How to read live data from OBD II? (Solved)

Scan tools plug into the OBD II port and display the data on the tool’s screen. But you can also access OBD II data by using a Bluetooth or WiFI dongle and a corresponding Bluetooth or WiFi OBDII app. The dongle plugs into the OBD II port on your vehicle and broadcasts the data to the app on your phone or tablet.

What is live data on scan tool?

Live Data allows you to view vehicle sensor, switch and relay inputs in real time, while the engine is running. LIVE data information helps pinpoint the problem components for a faster diagnosis.

What should O2 sensors read on live data?

An oxygen sensor will typically generate up to about 0.9 volts when the fuel mixture is rich and there is little unburned oxygen in the exhaust. When the air/fuel mixture is balanced or at the equilibrium point of about 14.7 to 1, the sensor will read around 0.45 volts.

In which OBD2 mode can a technician view live data?

In addition to the status of the monitors, Mode 1 is home to Current Data, also called Live Data. This is the screen showing the PID information live. Unlike some OE enhanced PIDS, however, Global OBDII PIDs are ACTUAL data.

What is Ltft B1?

LTFT B1 is Long Term Fuel Trim engine cylinder Bank 1. LTFT B2 is Long Term Fuel Trim engine cylinder Bank 2.

How do you read a freeze frame data?

Another example of how to interpret freeze frame data

  1. Fuel System 1 Status = 1.
  2. Fuel System 2 Status = 1.
  3. Fuel System 1 Status = 1.
  4. Fuel System 2 Status = 1.
  5. Calculated Load = 22. 16 %
  6. Engine coolant temperature = 87 deg C.
  7. Short term fuel trim (Bank 1) = 0%
  8. Long term fuel trim (Bank 1) = +11.65%

What is Calc load OBD2?

Let’s define OBD II calculated load: Reaches 1 at full open throttle for any altitude, temperature and pressure or rpm for both naturally aspirated and boosted engines. Indicates percent of peak available torque. Linearly correlated with engine vacuum. Often used to schedule power enrichment.

What data can you get from OBD2?

The presence of the OBDII allows telematics devices to silently process information such as engine revolutions, vehicle speed, fault codes, fuel usage and more. The telematics device can then use this information to determine trip start and finish, over revving, speeding, excessive idling, fuel consumption, etc.

What is live data in automotive?

Using the live data function of the FIXD scanner and app allows you to literally talk to your car when diagnosing most check engine light problems.

What are the symptoms of a bad oxygen sensor?

Here are some of the most common signs that your oxygen sensor is bad.

  • A Glowing Check Engine Light. The bright orange Check Engine light in your dashboard will usually glow if you have a bad oxygen sensor.
  • Bad Gas Mileage.
  • An Engine That Sounds Rough.
  • An Emissions Test Failure.
  • An Older Vehicle.

What can OBD2 read?

A good OBD2 scanner can also be used to troubleshoot things like the oil pressure, spark-plug misfires, and even pull the vehicle’s identification number from the internal computer.

What is Mode 6 on a obd2 Scanner?

Mode 6 is defined as test results and other component/system monitoring. The vehicle runs self tests on its various systems and components to determine everything is running within the operational standard. Mode 6 is where the engine computer stores all of the results from these tests.

What is Mode $0 A?

Mode $0A— Request emissions-related diagnostic trouble codes with permanent status after a clear/reset emission-related diagnostic information service. The purpose of mode $0A, referred to as Mode 10, is to allow a scan tool to obtain DTCs that are stored as “permanent codes.” These are codes only the module can clear.

What are the 10 obd2 test modes?

OBD Modes

  • Mode $01 – Request Live Data.
  • Mode $02 – Request Freeze Frames.
  • Mode $03 – Request Stored Trouble Codes.
  • Mode $04 – Clear/Reset Stored Emissions Related Data.
  • Mode $05 – Request Oxygen Sensors Test Results.
  • Mode $06 – Request On-Board System Tests Results.
  • Mode $07 – Request Pending Trouble Codes.

How to Read Live Data From OBD II Scan Tools

Hello, my name is Matt– In most cases, a basic OBD2 scan tool will suffice, and we’ll show you how to read live data from OBD ii diagnostic scanners in this tutorial today. It makes no difference whether you have a wired or wireless code reader, or if you choose Wi-Fi over Bluetooth depending on the device you’re working with. Developing an understanding of how to analyze live data from an OBD2 scanner is a valuable skill for diagnosing drivability issues in your vehicle. Prior to the widespread availability of low-cost OBD2 scan equipment, technicians were required to acquire pricey manufacturer scan tools.

However, even the most basic OBD2 scanner can now not only scan for and read diagnostic problem codes, but it can also read them (DTC).

And while the data alone will not disclose the precise solution to any difficulties with the motor, it will provide you with a bird’s eye perspective of the situation, allowing you to pinpoint the source of the problem.

First Things First

It is necessary to have a code reader, also known as an OBD2 Scanner, before you can begin your engine diagnostics. Please read the following articles if you do not already own a scanner: If you do not yet own a scanner, please read the following articles: Brief Recommendation The BAFX is an excellent choice for Android users. If you have an iPhone (or an Android device), the Bluedriver app is a fantastic option. Sale Additional choices include: After you’ve completed that, ensure sure the device is properly connected to the port and that it is associated with your phone (if you have a wireless one).

This just indicates that the engine has been warmed up to a comfortable 180-190 degrees Fahrenheit, allowing you to view the genuine figures from the sensors rather than the general values from the computer.

How to Interpret Generic Scanner Data

You’ll need a code reader, also known as an OBD2 Scanner, to get started with your engine diagnostics. In case you don’t already have a scanner, we’ve prepared a number of articles regarding the many models that we use: Advice in a Hurry The BAFX is a fantastic Android-based choice. Bluedriver is an excellent choice if you have an iPhone (or Android). Sale Optional extras include the following. Afterwards, make certain that it is properly inserted into the port and that it is properly associated with your phone (if you have a wireless one).

Just know that the engine has been warmed up to a comfortable 180-190*F, allowing you to see the genuine numbers coming in from the sensors rather than the computer’s bogus readings.

STFT (short-term fuel trim) and LTFT (long-term fuel trim).

When reading live data from any OBD2 scan tool, it is always a good idea to double-check the STFT (short-term fuel trim) and LTFT (long-term fuel trim) (long-term fuel trim). The fuel trim is critical in determining how the engine’s electronic control unit (ECU) controls the distribution of gasoline to the engine. The scan tool expresses both the STFT and the LTFT as a percentage of the total time. A value in the range of 5 percent is good for both the STFT and LTFT; anything higher or lower than 10 percent or lower than -10 percent is not acceptable.

  • This indicates that the vehicle may be experiencing issues with the fuel system, injectors, oxygen sensors, or mass air flow sensor.
  • The bottom line is as follows: Whether you’re looking at SHRTFT, LONGFT, or negative and positive levels, you want to see single digit values!
  • A Negative/Lower fuel trim, on the other hand, indicates that the CPU is attempting to alter the fuel mixture to lean in order to compensate for a rich mixture.
  • If the STFT or LTFT readings are greater than 10%, this indicates that there is an issue with the fuel delivery system.
  • By itself, this will give you a good understanding of the likely reasons of any engine problems you may be experiencing in your car.

If everything goes according to plan, the STFT data reading should swiftly move between rich and lean. The LTFT should reflect a more consistent percentage in comparison to the previous one. It’s important to remember that the fuel trim should be checked three times:

It is critical to monitor the fuel trim during all of the essential operational phases. Using the above example, suppose the LTFT is at 20 percent during idle but adjusts correctly to 5 percent between 1,500 and 2,500 rpm. In this case, the focus should be on specific problems that are causing the lean engine condition at idle speed. However, if the LTFT remains at 20 percent throughout the process, this might indicate an issue with the fuel delivery, such as a faulty fuel pump. Ratchets and Wrenchescreated an excellent video showing in detail how to adjust fuel trims.

Plug for the Engine Coolant Sensor

Engine Coolant Temperature

Ideally, the engine coolant temperature should be 190 degrees Fahrenheit or greater while the engine is operating at its optimal operating temperature. In order to compensate for a cold motor, the ECU will enrichen the fuel mixture and increase the idle speed when the ECT is lower than normal.

Intake Air Temperature and Air Injection

In order for the engine to operate at its optimal temperature, the coolant temperature should be 190 degrees Fahrenheit or greater. In order to compensate for a cold motor, the ECU will enrichen the fuel mixture and increase the idle speed when the ECT is lower than the specified value.

Mass Airflow

The information from the MAF sensor, also known as the mass airflow sensor, will be presented in grams per second or pounds per minute. The majority of current automobiles’ MAF sensors are fitted with a hot wire that estimates the volume of air being drawn in. If the wire is unclean or broken, it might result in an incorrect reading, causing the ECU to change to either a lean or a rich condition depending on the reading.

Manifold Absolute Pressure

The manifold absolute pressure sensor, often known as the MAP sensor, is used by the ECU to determine the engine load. According to the make and model of your car, it may or may not be equipped with a MAF and MAP sensor, or it may have both. When the engine is not running, the usual MAP sensor reading is 29.6 inches hg at sea level, and it is roughly 9.6 inches hg when the engine is running at idle speed. When the engine is running at full power, the reading might go as high as 29.6 inches.

Ignition Timing

The ignition timing live data will show the amount of time the CPU is adding or deducting based on certain sensor inputs, and it will be shown in real time. If the MAP sensor sends out a lean command, the CPU will alter or advance the time to accommodate the situation. If the MAP reading is very rich, the CPU will delay the execution of the program. Because of the increased workload on the engine, the CPU will additionally delay the ignition time to avoid an early explosion.

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Oxygen Sensors

To manage the fuel mixture in the motor, the CPU uses the output voltage of the O2 sensors as a control signal to operate. To examine the state of the catalytic converter, you may also utilize real-time data collected from the oxygen sensors. The oxygen sensors will need to measure voltages more than 0.8 volts and less than 0.2 volts, and they will need to shift swiftly as you step or snap-test the accelerator pedal. The switching rate of the rise and fall in O2 sensor voltages should be less than 100 milliseconds in order to ensure proper operation.

According on the vehicle’s make and model, there will most likely be two or more oxygen sensors installed in the exhaust system. If the catalytic converter is functioning properly, the voltage reading from the rear O2 sensor will remain constant.

Engine Revolutions per Minute or RPM

The engine speed is measured in RPM, or revolutions per minute. The ECU makes use of the RPM information to fire the ignition coils and pulse the fuel injectors, among other things. When driving a car with an automatic gearbox, the RPM data will be used by the ECU to regulate the operation of the torque converter as well as the shift points as the vehicle is being driven forward.


It is hoped that this article has provided you with a solid foundation for reading live data from OBD II scanners. There’s surely enough material for each of these sensors to fill a full blog article, so you’ll have to rely on this guide as a road map for your research. If we get the opportunity in the future, we will expand on this. Matt

Here’s How To Become a Car Whisperer Using OBD2 Live Data

Modern vehicles are packed with cutting-edge technology that are controlled by a variety of computer systems, each of which is controlled by a plethora of sensor inputs. Any system malfunction is instantly communicated to the driver through the use of a check engine light, and the use of anOBD2scan tool may assist identify which part of the vehicle is having a malfunction. All of these sensors and computers are capable of displaying live data in real time in order to facilitate diagnostics; however, in order to do so, you must first have the appropriate scan tool.

Benefits of Live Engine Sensor Data

Identifying the diagnostic issue code that resulted in the malfunction indicator light turning on isn’t always enough to correct the problem. It is possible that a malfunctioning sensor or defective wiring can cause the check engine light to illuminate, so before you head to the junkyard to replace a component, take the time slow down and attempt to thoroughly diagnose and repair the problem. Furthermore, some powertrain and driveability concerns will not always result in the illumination of the check engine light.

When you watch live sensor data, you can observe how the engine and its computerized systems are performing in real time, which is a significant advantage.

This encompasses everything from the air and fuel mixture to the emissions and engine speed, among other things.

The ability to monitor live OBD2 data through theFIXD scannercan make the work a little simpler, even for a seasoned technician who is accustomed to dealing with such situations.

Additionally, if the diagnostic issue code indicates a defective sensor, double-checking the live data might confirm that the part is indeed faulty (and not another ailment such as improper wiring) before investing the money on a replacement sensor is a wise decision.

How to View Your Car’s Live Data with FIXD

When utilizing live data to diagnose a problem with your automobile, the first step is to connect the FIXD scanner to your vehicle’s OBD2 port and launch the FIXD mobile app on your smartphone. The engine must be operating in order to make use of the scanner and app. Although it varies depending on the sort of issue you are attempting to identify, most diagnostic tests need that the engine be working in a closed loop, which means that the engine must be warmed up before being used. Essentially, this refers to the engine’s computers and sensors being in a closed loop, and you can generally hear when this occurs after you start your engine and the idle speed lowers to a lower, more silent rpm as the engine warms up.

View Live Data and Track Down Your Problem

A FIXD scanner with an OBD2 port is accessible on all gasoline-powered cars, trucks, SUVs, and vans (as well as diesel vehicles constructed in 2008 and after), however the parameters that are displayed in the FIXD scanner live data display will differ based on the year, make, and model of your vehicle. My vehicle (a Kia Telluride) was equipped with a sensor that was capable of reading over four dozen parameters from the Engine Control Module, which were then displayed in real time (up to four parameters at a time) on my smartphone.

Below Is the List of Live Data Feeds Allowed Through the FIXD App As Read From A Kia Telluride SUV

Engine Load Estimation Calculation Engine Temperature of the coolant Engine RPM Vehicle Speed Throttle Position Run Time Since Engine Start Distance Traveled with MIL On Warm-Ups Since Codes Cleared Distance Traveled Since Codes Cleared Distance Traveled Since Codes Cleared Distance Traveled Since Codes Cleared Control Module is an abbreviation for Control Module. Voltage Fuel TrimBank for the Short Term 1 Fuel Trim Bank for the Long Term 1 Fuel Trim Bank for the Short Term 2 Fuel Trim Bank for the Long Term Two-stage intake manifold with absolute pressure timing and advance intake.

System for measuring fuel tank level input and evap Absolute Barometric Pressure Vapor Pressure Absolute Barometric Pressure Oxygen Sensor1 Current Oxygen Sensor5 Current Catalyst Oxygen Sensor1 Current Oxygen Sensor5 Current Bank of the Alps Temperature: Temperature of one sensor and one catalyst: Bank 2 Sensor 1 Catalyst Temperature: Bank 1 Sensor 2 Catalyst Temperature: Bank 2 Sensor 2 Absolute Load Value: Bank 2 Sensor 2 Catalyst Temperature: Bank 2 Sensor 2 Absolute Load Value: Bank 2 Sensor 2 Absolute Load Value: Bank 2 Sensor 2 Absolute Load Value: Bank 2 Sensor 2 Absolute Load Value: Bank 2 Sensor 2 Absolute Load Value: Bank 2 Sensor 2 Absolute Load Value: Bank Equivalence of Fuel and Air Commanded Ratio Throttle Position in Relation to the Environment Throttle Position B Absolute Air Temperature Absolute Throttle Position Throttle Position D is the absolute position of the throttle.

As long as the trouble codes have been cleared, the absolute throttle position E command throttle actuator time run with the MIL on time has been in effect.

Actual Engine Torque as a Percentage Torque Reference for the Engine

How to Read and Interpret Live Sensor Data

You can see from the Kia example that FIXD displays a wide range of real-time sensor information. This list, on the other hand, may appear very different to you. It doesn’t matter what data you can access on your vehicle’s make and model; here’s an overview of what to look for in the most frequent OBD2 live data readings:

Fuel Trims: Short Term Fuel Trim (STFT) and Long Term Fuel Trim

Because of the Kia example, it is possible to observe a wide variety of live sensor data. This list, on the other hand, may appear completely different for you. It doesn’t matter what data you can access on your vehicle’s make and model; here’s an overview of what to look for when viewing the most frequent OBD2 live data readings:

Oxygen Sensor Voltage

You may use the oxygen sensor to find out what the air-to-fuel ratio of your exhaust is so that the engine can make changes if more or less fuel is required to operate the vehicle effectively. This level will be represented in terms of voltage by FIXD. A measurement of 0.45V should be obtained if the oxygen-to-fuel ratio is perfectly balanced. However, due to the fact that this is almost seldom the case, the voltage will most likely oscillate around 0.5V.

Engine Revolutions Per Minute (RPM)

The number of revolutions per minute, or RPM, indicates how quickly the engine turns. Having an understanding of your engine’s revolutions per minute (RPM) can help you decide when to shift gears in a manual transmission, maximize your mileage by shifting at the appropriate time, determine if your engine and transmission are in proper working order, and drive your car safely without damaging the engine. While your automobile is idle, keep an eye on the RPM. The speed should be between 600 and 1000 rpm.

Motorcycles will have a higher rpm range, ranging between 1000 and 1500 rpm.

Intake Air Temperature

The number of revolutions per minute, or RPM, indicates how rapidly the engine turns at any one time. Having an understanding of your engine’s revolutions per minute (RPM) can help you decide when to shift gears in a manual transmission, increase mileage by shifting at the appropriate time, determine if your engine and transmission are in proper working order, and drive your car safely without causing damage to it. Keep an eye on the RPM of your vehicle when it is idle. You want it to spin at a rate of 600 to 1000 rpm.

Motorcycles will have a higher rpm range, ranging between 1000 and 1500.

Engine Coolant Temperature

When an engine is working at its optimal temperature, it is between 190°F and 220°F. The ECU will add more fuel to the mixture and increase the idle speed in order to compensate for colder temperatures if the measurements fall below this threshold.

Ignition Timing

Setting the proper ignition timing in a spark ignition internal combustion engine is critical to the engine’s performance. When a spark occurs either too early or too late, it can create vibrations and harm to the surrounding area.

The timing of the engine’s ignition has an impact on the engine’s lifetime, power, and fuel consumption. The amount of time the engine’s computer is adding or removing based on sensor inputs may be determined by looking at the engine’s ignition timing live data.

Mass Air Flow

It is the Mass Air Flow (MAF) sensor that determines how much air is entering the internal combustion engine’s intake system. Hot wire mass air flow sensors are the most common form of mass air flow sensor, however there are other varieties available. Typically, an internal air temperature (IAT) sensor is fitted within the MAF sensor to measure the temperature of the internal air. With this air flow sensor, you can optimize your engine’s air-fuel ratio while also determining when to change gears in the gearbox and lowering the quantity of exhaust emissions.

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However, the output is frequently represented in terms of grams per second or voltage.

If your engine has a defective MAF sensor, it may be difficult to start, may hesitate when under load, may run rough, or it may be abnormally rich or lean when it is running.

If you believe that there is a problem with your mass air flow sensor, utilize FIXD to scan for check engine code information.

  • P0100
  • P0101
  • P0102
  • P0103
  • P0104
  • P0171
  • P0172
  • P0173
  • P0174
  • P0175
  • P0100
  • P

Manifold Absolute Pressure

To function properly, your engine requires the proper mixture of air, gasoline, and spark. The manifold absolute pressure (MAP) sensor contributes to the smooth operation of this combination, allowing you to get to where you’re going without incident or delay. More specifically, the MAP sensor monitors the volume of air entering the manifold, the temperature of the air entering the manifold, and the number of rotations the engine is making. Your ECU may make adjustments to fuel and airflow based on this information to guarantee optimal operating efficiency.

It is necessary to understand how the OBD2 scanner interprets MAP sensor data in order to correctly interpret it.


Normal MAP readings at sea level with the engine off are 29.6 inches of mercury, and when the engine is idling, the readings are approximately 9.6 inches of mercury.

Congratulations Car Whisperer

If you understand what live data is and how to interpret it using the FIXD scanner and app, you’ll be on your way to being a genuine vehicle whisperer before you know it. Diagnose issues like never before and save hundreds of dollars in diagnostic costs from repair shops! If you don’t already have an easy-to-use OBD2 scanner, such as FIXD, to read your car’s live data, make sure to check it out right now! Automobile fanatic throughout much of his life, with a particular fondness for offroading.

I’m a former wrencher who now works as a writer, but I still like tinkering with just about anything that has an engine. A tie between a ’71 Hemi ‘Cuda and a ’91 GMC Syclone for the ultimate dream automobile. GirlDadSaveTheManuals

How To Read Live Data From OBD II

With the introduction of OBD II, vehicle diagnostics got significantly easier. The technology was an improvement over the original On-Board Diagnostics (also known as OBD 1) system that was previously in use. Following the introduction of this specific sort of computerized system in 1994, automobile manufacturers began to rely on it more frequently. All automobiles made after 1996 must be equipped with the more advanced OBD II diagnostic technology, which was mandated by the United States in 1996.

Several OBD II scanners are already available on the market, making it easy for the average person to collect diagnostic data for their car.

In this post, we’ll go over the fundamentals of how live data works in an OBD2 scanner and how to use it.

Also interesting: How to read live data from OBD II? (Solved)

How Does The OBD2 Technology Work?

It is necessary to understand how the technology works before we can examine the real-time data provided by a scan tool that connects to the OBD II port on a vehicle. This will give you a better understanding of what to expect, as well as allowing you to determine the accuracy of the prediction. AnOBD2 scanner attaches to a port situated on the dashboard of your vehicle. However, while the exact position of theOBD IIport varies from one automobile to another, the overall concept of the port stays the same.

  1. The On-Board Diagnostic system is capable of diagnosing a wide range of problems in your car.
  2. These sensors work together to establish a full network that runs throughout the vehicle.
  3. Because the sensors are dispersed throughout the vehicle’s structure, it is possible to collect a variety of various forms of information.
  4. Some of these devices are designed to only be utilized while the check engine light is illuminated, while others are not.
  5. A scan tool that allows you to access real-time data, on the other hand, will often provide you with more information to work with.
  6. Aside from that, they may be used to assess the overall performance of a vehicle as well.
  • It is necessary to understand how the technology works before we can examine the live data shown by a scan tool that connects to the OBD II port. In addition to providing you with a greater understanding of what to expect, this will also allow you to determine the accuracy. In order to use anOBD2 scanner, you must connect it to a connector on the dashboard of your vehicle. However, while the exact position of theOBD IIport varies from one vehicle to another, the overall architecture of the port stays same. There is a connection between the port and the computer system that is integrated inside the automobile. The On-Board Diagnostics system is capable of diagnosing a wide range of problems in your car, including engine and transmission problems. Along with the port and computer, the system is comprised of a number of other sensors. Throughout the vehicle, these sensors work together to establish a network. Each of the sensors transmits data to a computer system that is part of the On-Board Diagnostics technology that is utilized in the automobile to diagnose the vehicle’s condition. Because the sensors are dispersed throughout the vehicle’s structure, it is possible to collect a variety of various forms of information. Specific information about the data that may be read will vary depending on the OBD2 scanner you choose to use. When the check engine light is illuminated, several of these gadgets are only intended to be utilized. This implies that the scan tool’s sole goal will be to provide you with the error codes that the engine has provided to you. When you use a scan tool that offers you access to live data, on the other hand, you will almost always be able to get additional information to use. When the check engine light illuminates, these tools can be utilized. Additionally, they may be used to assess the overall performance of a vehicle. An OBD2 scanner may be able to supply you with the following real-time data:

Of course, this is only a partial list of the live data that is available to you.

These scan instruments are typically equipped with extra features to guarantee that you can detect even the smallest problems with your car. Because the scan tools give real-time data, you can detect an issue early on, which can help you avoid more serious problems down the road.

Understanding OBD2 Live Data Codes

Once an OBD2 scanner has been synced with your vehicle, a variety of codes can be shown on the screen. Each code is associated with a specific part of the vehicle and gives information derived from data collected by the sensor network. In this part, we’ll take a look at some of the most frequent codes, as well as the data that goes along with them. Being familiar with live data codes and their meanings can aid in making the diagnostics procedure more efficient.

Oxygen Sensor

As soon as an OBD2 scanner is synced with your vehicle, it will show a variety of codes. Each code is associated with a specific part of the vehicle and gives information derived from data collected by a sensor network in the vehicle. Following that, we will look at some of the more frequent codes as well as the data that goes along with them. An in-depth understanding of live data codes can aid in the optimization of the diagnostics workflow.

Fuel Trim

Your automobile is equipped with an engine control module, often known as an ECM, which is responsible for delivering fuel from the tank to the engine. This mechanism is also in charge of adjusting the ratio of air to fuel in the combustion chamber. The emission control system is regulated by it, and it plays a part in that regulation. When it comes to fuel trim, you’ll often get two values. There are two types of fuel trim: long-term fuel trim and short-term fuel trim. The codes that are often used to describe them are LTFT and STFT.

  • When the figure is more than zero percent, it indicates that extra gasoline has been added.
  • The optimal STFT measurement should fall between 10 percent and -10 percent of the maximum value.
  • The STFT reading should be continually fluctuating between positive and negative percentages while keeping a watch on this real-time data.
  • Looking at the LTFT reading, on the other hand, you should observe a value that is more consistent over time.
  • Similarly to STFT and LTFT, vacuum leaks have the potential to cause measurements to differ from one another.

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When using a high-quality OBD II scan equipment, it should be possible to obtain information about the temperature at specified places. This covers the temperature of the intake air as well as the temperature of the engine coolant. Throughout the day, the IAT sensor continuously monitors the temperature of air moving towards the engine. The information is given back to the ECM, which uses it to aid in the process of blending the air and fuel. This is significant because the density of hot and cold air differs.

For engine coolant temperatures, a desirable range would be somewhere between 190 and 220 degrees Fahrenheit, according to the manufacturer’s recommendations.

When the temperature of the engine coolant decreases to a lower level, the ECM will respond by increasing the amount of fuel supplied to the combustion mixture. This will also lead the ECM to begin increasing the idle speed of your vehicle.

How Do I Read Live Data From OBD II?

According on the device you choose to use, the particular technique for diagnosing problems with a car utilizing OBD II data will vary. Also critical is an understanding of the device’s operation and operation. Checking the manufacturer’s instruction booklet that comes with the OBD2 scanner is an excellent place to start. Despite the fact that these devices may appear to be identical to one another, the particular operation instructions may change significantly across the various possibilities.

  • Portable solutions are preferred by many individuals since they are equipped with wireless technology and allow you to keep reports on a linked device.
  • Before you can use it, you’ll need to download an application to your smartphone to get started.
  • There are, however, certain choices that make use of specialized applications that have been developed by the company.
  • Make certain you read and follow the manufacturer’s directions.
  • Following are a handful of the highest rated universal applications that are supported by a large number of OBD2 scanner devices.
  • Torque Pro
  • OBD Auto Doctor
  • InCarDoc Pro
  • EOBD Facile
  • HobDrive
  • Dash
  • OBDeleven
  • EO
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Some of these programs, such as Torque Pro, are paid subscriptions. The premium versions of the apps often provide you a greater number of features that you can use to diagnose problems with your vehicle. The functionality of the app is dependent on the exact software that you choose to download. You will need to make sure that the Bluetooth function on your smartphone is enabled. Most of the time, the app you use will assist you with synchronizing your smartphone with the scanner. Before attempting to link the device with your smartphone, you will need to turn the ignition of your car to the ‘drive’ position.

To begin the sync process, follow the instructions provided by the app on your phone.

Most applications will provide you with a dashboard that displays the most relevant data – such as the fuel mixture, short-term fuel trim, and data from the oxygen sensor – in one convenient location.

Besides obtaining data from your vehicle, such as the fuel system utilized, the OBD2 scanner may also present suggested fixes that take this information into account.

How To Read And Interpret live Sensor Data?

The mechanism that is utilized to read the live sensor data is primarily dependent on the app that has been loaded on your smartphone. The app will most likely display a message along with certain codes if you connect to the scanner after the check engine light has illuminated. Each code corresponds to a defect that has been discovered by sensors in the vehicle. Some applications will provide you with information about each of the codes that are presented. The procedure of understanding the live sensor data becomes substantially simpler as a result of this.

Alternatively, if the app just provides codes, you may be required to search them up on the internet or on another mobile application. As soon as you figure out what each code is meant to indicate, you’ll have a better grasp of why your car is having specific issues.

Benefits Of Live Engine Sensor Data

Live data from the engine might provide you with a variety of advantages. In order to compare scanners that give live data with those that just produce fault codes, it is critical to understand the advantages of each type of scanner. The most important thing to remember in this situation is that merely being able to view an error number may not be indicative of much. A code related to air fuel or an issue with the coolant temperature may be shown on your dashboard. Despite the fact that the code is informative, it may still be necessary to go through a number of diagnostic steps in order to pinpoint the exact problem.

  1. It is at this point that the advantages of a live engine sensor are realized.
  2. You can narrow your attention to data from certain aspects that contribute to the error code being shown.
  3. It also makes it possible to locate the particular area that requires your attention.
  4. As soon as you have cleared the fault codes that are now recorded in the memory of the OBD II system, you may restart the vehicle and wait for the check engine light to illuminate once more.
  5. This not only simplifies the diagnostics procedure, but it also improves the overall accuracy of the results you obtain.
  6. To further appreciate how an OBD2 scanner might save you money, let’s take a look at a hypothetical situation.
  7. This indicates that it is time to connect to the scanner and do a fault code investigation.
  8. The first notion that comes to mind is to purchase a new sensor.
  9. After analyzing all of the data and performing a thorough inspection of the components, you realize that faulty wiring is the root cause of the sensor’s failing.

The above is only one possible situation, and each individual’s experience with an OBD2 scanner to identify problems with their car will be unique. Also see: Best OBD2 Splitter Reviews.


When the check engine light illuminates, OBD II technology enables you to obtain diagnostic information. With the capacity to display real-time data, you can more effectively diagnose problems, which makes the process of obtaining the appropriate repair easier overall. People who are utilizing an OBD2 scanner for the first time may find the information given to be a little puzzling. It is critical to comprehend what the information presented means, whether you are checking for long-term fuel trim, intake air temperature, or any other data.

Pilar is a Brazilian editor on the road who currently resides in Bali.

She is one of those minimalists who like to purchase just the greatest items in order to do it only once.

Interpreting Generic Scan Data

When the check engine light illuminates, OBD II technology allows you to obtain diagnostic data. With the capacity to display real-time data, you can more effectively diagnose problems, which makes the process of obtaining the proper repair easier overall. A lot of the information given by an OBD2 scanner might be overwhelming for folks who are using one for the first time. If you’re looking for long-term fuel trim, intake air temperature, or any other data, it’s crucial to understand what the information represents.

The writer Pilar is a Brazilian travel editor now based in Bali.

She identifies as a minimalist, meaning she prefers to purchase just the nicest items that she will use once.

Additional OBD II Parameters

Let’s have a look at some of the more current OBD II parameters that have been introduced. These characteristics were added to cars equipped with CAN in 2004, however they may also be found on previous models or vehicles that are not equipped with CAN. For example, the air/fuel sensor data were previously accessible on Toyota OBD II cars from prior generations. Picture number two was obtained from a 2005 Dodge Durango and displays several additional characteristics that were implemented. The following are the parameter descriptions from Fig.

  • Status: The fuel system status will show more than simply Closed Loop (CL) or Open Loop (OL) operation (OL).
  • It is possible to utilize this parameter to determine when a certain problem occurs during an engine run cycle.
  • This parameter can be very useful in determining how long a customer has allowed a problem to persist while MIL is activated.
  • A COMMAND EGR = EGR PCT indicates that the commanded EGR is reported as a percentage and is normalized across all EGR systems.
  • Keep in mind that this parameter does not indicate the quantity of EGR flow; rather, it reflects simply the amount of EGR flow that the PCM is dictating.
  • It is also possible to normalize the EGR Error for all different types of EGR systems.

Suppose the EGR valve is ordered open by 10% but only moves by 5% (5 percent x 10%) x 10% Equals a 50 percent mistake in the opening of the EGR valve As an example, if the scan tool displays EGR Error at 99.2% and the EGR is requested to be turned off, this implies that the PCM is receiving information indicating that the EGR valve position is larger than 0 percent.

For all types of purge systems, the parameter EVAP PURGE equals the value of EVAP PCT.

When EVAP Purge Control is turned off, the percentage displayed will be zero, and when EVAP Purge Control is turned on, the percentage displayed will be one hundred percent.

Because of typical purge operation, it is possible that fuel trim measurements will be aberrant.

When trying to complete system monitoring and identify particular problems, the fuel level input (FUEL PCT) is an extremely valuable parameter to have on hand.

You may have difficulties running the misfire monitor if the fuel level is less than 15 percent when attempting to mimic a misfire scenario by monitoring misfire counts.

WARM-UPS = WARM UPS: This option will keep track of how many warm-ups have been performed since the DTCs were cleared.

If you’re seeking to reproduce a certain code that takes at least two warm-up cycles to complete, this option will be beneficial in confirming the warm-up cycles.

Check the correctness of this parameter KOEO in relation to your elevation by entering it into the calculator.

The temperature value can be received directly from a sensor or inferred from other sensor inputs, as in the case of a thermometer.

This parameter, CTRL MOD (V) = VPWR, astonished me because it was not included in the original OBD II specification.

In order to be accurate, the voltage shown must be near to the voltage existing at the battery.

Keep in mind that the PCM receives voltage from a variety of sources.

ABSOLUT LOAD = LOAD ABS: This parameter represents the normalized value of air mass per intake stroke, expressed as a percentage of the total air mass per intake stroke.

The information is used to plan the ignition and exhaust gas recirculation rates, as well as to calculate the engine’s pumping efficiency for diagnostic reasons.

During open-loop operation of traditional oxygen sensor vehicles, the scan tool should display 1.0 in closed-loop operation and the PCMcommanded EQ ratio in closed-loop operation.

To find out what the real A/F ratio is that is being requested, multiply the stoichiometric A/F ratio by the equalization factor (EQ).

Using the example above, the commanded EQ ratio is.95, and the commanded A/F is 14.64 0.95 13.9 A/F.

2 will be beneficial in diagnosing problems with the system.

The vehicle does have more parameters that may be of interest, but they are not shown or accessible on this vehicle.

Additionally, wide-range and linear air/fuel sensors are reported per sensor in either voltage or milliamp (mA) readings, if they are made accessible.

5 above is taken from the Vetronix MTS 3100 Mastertech system.

The blue circle around the equal sign (=) indicates that this parameter is supported by more than one ECU and that equivalent values have been received for this parameter.

), which indicates that no answers have been received for this parameter, despite the fact that it should be supported by the system.

As you can see, general data from the OBD II has progressed significantly, and the information may be quite beneficial during the diagnostic procedure.

Taking the time is essential.

The benefits will begin to accrue immediately.

Please keep in mind that not all manufacturers adhere to the OBD II generic specification, making it necessary to thoroughly examine the vehicle service information for deviations and requirements prior to performing the diagnostics. Obtain a PDF version of this document.

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