What the P0508 code means. The P0508 code means that the powertrain control module has sensed that there is some type of inconsistency in the engine idles RPM. Whenever the PCM discovers that the engine is idling too high or too low, it will try to correct the RPM.
- P0508 Lexus Idle Air Control Valve Sense Circuit Low Possible causes – Dirty throttle body – Electric throttle control actuator misadjusted or damaged – Faulty Electric throttle control actuator – Intake air leak – Poor electrical connection to the Intake Air Control (IAC) valve
How do you know if your IAC valve is bad?
Common signs include irregular or unusually high idle speed, the Check Engine Light coming on, and stalling while idling.
How do I fix code P0508?
Clean the electrical connections and circuits in the IAC to make sure it’s working properly. Repair or replace connections as needed, such as burnt, corroded, or damaged electrical connectors. Check the engine for vacuum leaks that might be contributing to uncontrollable engine RPM.
What happens when IAC valve goes bad?
If the idle air control valve (IAC) fails completely; it may leave the vehicle, without a source of air to maintain a proper idle. This may result in the engine stalling while operating. And, in some cases, may result in an engine that will not idle at all; or stalls as soon as it is started.
How do I reset my IAC sensor?
If you removed the air intake, ensure you reconnect the MAF sensor (if equipped). Turn the ignition ON and leave on for several seconds then turn the ignition OFF to allow the ECM to reset the IAC valve. You should be good to go.
What happens if IAC is stuck open?
An obstructed or stuck-shut IAC will result in a rich air-fuel ratio at idle, so the engine will start very easily while cold and then die suddenly after a slight puff of black tail-pipe smoke. A stuck-open IAC might start fine while warm and may continue to run if the engine reaches high-enough RPM.
Can IAC cause hesitation?
Your IAC Valve May Be To Blame. You press down on your gas pedal and expect your car to take off smoothly, but that may not always happen. You might be experiencing hesitation due to a bad IAC valve (or idle air control valve).
What is engine code P0508?
What the P0508 code means. The P0508 code means that the powertrain control module has sensed that there is some type of inconsistency in the engine idles RPM. Whenever the PCM discovers that the engine is idling too high or too low, it will try to correct the RPM. If they can’t, it will store the code.
Can a bad IAC valve cause no start?
A faulty IAC can also cause a crank no start. You also have a code for the oil psi sensor which can also cause a no start on some vehicles. This may require that you track down a service manual for the vehicle you’re working on.
Can I drive with a bad IAC valve?
Technically, you may be able to drive with a bad IAC —but you should not continue doing so. A bad IAC can potentially lead to stalling, which can compromise vehicle safety. Plus, you won’t pass a state emissions test if the check engine light is on due to a bad IAC.
Can a bad IAC valve cause a misfire?
IT CANT CAUSE A MISFIRE UNLESS YOU HAVE A LEAK AROUND THE INTAKE MANIFOLD TO IDLE VALVE SEAL. Disconnect the wire leading to it with the engine off but ignition on. Then start the engine and see if it idles. If the idle speed is higher or lower than normal it is probably working.
How do I fix code P0505?
What repairs can fix the P0505 code?
- Replacing the IAC valve and cleaning the throttle body and passages.
- Removing carbon from throttle body and IAC passages and clean IAC.
- Repairing a vacuum leak in the engine intake manifold vacuum system or gaskets.
P0508 IAC valve sense circuit low.
This article will explain how to deal with a P0508 IAC valve sensing circuit low problem on a Chrysler car in the event that you experience one. In order to bypass air around the closed throttle plate that happens during idle, the Idle Air Control is controlled by a linear solenoid valve that opens in response to computer signals. The IAC has a tapered pintle, and the throttle body has a matching seat in the pintle. The PCM regularly checks the return voltage from the IAC to see if it is functioning properly, and it compares the actual RPM with the desired RPM.
The computer determines the ideal idle speed by analyzing the data from the throttle position sensor, crank position sensor, coolant temperature sensor, manifold absolute sensor, and switch situations such as brake, transmission range selection, and air conditioning.
It is closed during off-throttle driving, except when decelerating rapidly, when it opens slightly to function as a dashpot to gradually lower the idle speed down and prevent stalling.
Test the IAC
Battery voltage must be more than 10 volts when the engine is running in order to do the IAC testing. You’ll need a digital voltmeter as well as an ammeter for this project. Start the engine and listen for the engine to idle at 800-1,500 RPM, depending on the temperature of the engine. Then, using the gray/red wire that connects to the IAC, do a current draw test. The current must be less than 146 milliamps (mA). After checking that the current is within specification, turn off the engine and measure the resistance value across the IAC terminals.
- If it isn’t, the IAC should be replaced.
- Check for voltage at the PCM IAC terminal, which is the next step.
- A shorted IAC can cause damage to the drivers in the PCM, which can result in the occurrence of a P0508 IAC valve sensing circuit low fault code being displayed.
- Rick Muscoplat’s 2015 Rick Muscoplat’s Rick Muscoplat posted a blog entry on
Error Code P0508: Idle Air Control Circuit Low
Idle Air Control Circuit Low is the definition of the error code P0508. This indicates that the idle air control system circuit is operating at too low a voltage, which is manifested as irregularity in the engine’s idle RPM. This is a general issue code, which means that it applies to any vehicle equipped with an OBD-II system and manufactured between 1996 and the present day. Chrysler, Dodge, Hyundai, Mazda, and Jeep are among the companies that use it. There are differences between each vehicle’s make and model when it comes to the definition, diagnosis, and repairs, which is to be expected.
Any time the engine’s idle RPM is inconsistent, whether it is too high or excessively low, the PCM will attempt to fix the RPM issue by adjusting the engine’s speed. After attempting to resolve the issue, it will save the code. Other similar error codes are as follows:
- P0509 Idle Air Control System Circuit High is the error code that is shown. Error Code P0511 Idle Air Control Circuit
- Error Code P0518 Idle Air Control Circuit Intermittent
- Error Code P0511 Idle Air Control Circuit
- Error Code P0519: Idle Air Control System Performance Idle Air Control System Performance
This error code, like all other error codes, causes the Check Engine light to illuminate and the code to be stored in the vehicle’s memory system. Other signs and symptoms to look out for are:
- When the engine is running at a low speed or when the accelerator is not pushed, it stalls because of the low or high idle RPM. When the throttle is withdrawn, the engine comes to a complete stop. Noises coming from the throttle body locations that are unusual
It is possible that other IAC-related codes are present in some instances.
The following are some of the most common reasons of this code:
- IAC motor harness that is open or shorted
- Poor electrical connection in IAC as a result of the motor circuit
- IAC failure
- Throttle body bore contamination
How to Check
Connect an OBD-II scanner to the vehicle’s computer system in order to troubleshoot this error code. Check to see if any additional codes are present, make a note of the data, and then reset the codes to their default values. Check to see if the code reappears when driving the car. If the code returns, then it is time to investigate the various reasons, which may include the IAC. Check the bore of the throttle body. Make certain that it is clean. Then, during your test drive, observe if the code reappears after you have reset the device.
Whenever possible, repair or replace connections that are broken or corroded, such as burned, corroded, or damaged electrical connectors.
Vacuum leaks should be repaired, and the system should be checked again.
Alternatively, the PCM can be replaced, but this is highly unusual.
How to Fix
Depending on your diagnosis, the following common fixes may be necessary:
- Electrical contacts at the IAC system are repaired or replaced when they become broken
- Vacuum leaks are repaired
- The IAC is replaced
- The PCM is replaced (in rare cases).
Consult the vehicle’s information source for the suggested technique of testing the IAC motor with the DVOM before beginning your testing. If your results do not conform to the manufacturer’s standards, the most typical remedy is to replace the IAC motor or valve with an equivalent model.
P0508 Idle Air Control Circuit Low
The following article was written by Stephen Darby, an ASE Certified Technician.
What does that mean?
In this case, the diagnostic problem code (DTC) is a general powertrain code, which means it applies to any cars manufactured after 1996. (Dodge, Chrysler, Hyundai, Jeep, Mazda, etc.). Despite the fact that they are general, the particular repair processes may differ based on the make and model. An illuminated malfunction indicator lamp (MIL) and the recorded code P0508 on your OBD-II-equipped car indicate that the powertrain control module (PCM) has identified a fault with the intake idle air control (IAC) circuit, in this case a value that is lower than intended.
- Regulating the quantity of air that is permitted to bypass the throttle plate is beneficial for controlling engine RPM while the engine is running at a low speed.
- With such a little amount of air, the engine would be unable to maintain an idle and would most likely stall.
- Of course, when the throttle plate is opened, the auxiliary vacuum source would have a negative impact on the engine’s performance and fuel economy (upon acceleration).
- The plunger housing of the IAC valve is designed with two different apertures that allow air to travel through them to function properly.
- If the valve is open (when the plunger moves out of the opening), ambient air can flow through it and into the manifold; if the valve is closed (when the plunger fills the aperture), ambient air cannot flow through it and into the manifold.
- The PCM analyzes input data from the oxygen sensors, the throttle position sensor, and a variety of other sensors to calculate how much air should be allowed to skip the throttle plate and into the combustion chamber.
An error code P0508 will be saved and a MIL may be lit if the engine RPM levels do not correspond to the required restrictions that have been specified. The following are related idle air control system circuit fault codes:
- P0509Idle Air Control System Circuit High
- s P0511Idle Air Control Circuit
- s P0518Idle Air Control Circuit Intermittent
- s P0519Idle Air Control System Performance
A fault in the idle air control system might cause the engine to stall or to idle at an unusually high RPM, resulting in the engine being forced to stop. This code should be viewed as a serious matter that must be handled as soon as possible. Symptoms of a P0508 error code include the following:
- High engine revolutions per minute
- Engine stalling, particularly at idling
- Strange sounds coming from the throttle body region
- Additional IAC-related codes
The following are examples of possible causes for this code:
- Engine vacuum leak caused by a faulty IAC motor/valve. IAC control wires or connections that are open or shorted
- Carbon accumulation in the throttle body or in the IAC valve, for example A faulty PCM or a programming problem in the PCM
Diagnostic and Repair Procedures
The first step is always to look for technical service bulletins (TSB) for your specific vehicle, which may be found online. It is possible that your problem is a known issue with a known fix that has been released by the manufacturer, which can save you both time and money throughout the diagnostic process. The following tools and resources would be required in order to diagnose the code P0508: a diagnostic scanner, an electronic volt/ohmmeter (EVOM), and a reliable vehicle information source (All Data DIY will do).
- Aside from that, I’d look for any vacuum leaks in the engine that might be contributing to the engine’s unmanageable RPM level.
- After that, I’d attach the scanner to the vehicle’s diagnostic connector and collect all of the stored codes and freeze frame data from the vehicle’s computer.
- Now I’m going to clear the codes and put the car through its paces to determine whether it’s been reset.
- Additionally, look for any technical service bulletins or safety recalls that pertain to the vehicle and the fault in question.
- When the engine idle RPM is really high, I use a shop rag and my fingers to regulate the engine RPM at idle as a simple means of checking the IAC system.
- Following the removal of the IAC valve, I am able to maintain control of a high idle situation, which indicates that the IAC system is not operating properly.
- Large engine vacuum leaks can be caused by a leaking PCV valve or hoses, a leaking vacuum hose, a leaking vacuum brake booster, a leaking check valve or hoses, an EGR valve that has been jammed open, an EGR gasket leak, or an intake manifold gasket leak.
The suggested technique of testing the IAC motor with the DVOM should be obtained from your vehicle’s information resource. If the IAC motor/valve does not operate according to manufacturer’s requirements, it should be replaced. Additional diagnostic observations include:
- Before evaluating circuit resistance with the DVOM, make sure all relevant controllers are disconnected.
Related DTC Discussions
- The p0123 p1297 p0508 engine code in a 2002 Dodge neon has been fixed. P0123 p1297 p0508 engine code repairs The idling speed of the automobile is low. I can’t get my car to start without putting my foot on the throttle
- I need assistance. P0508 and P0509 for the 2003 Dodge Dakota My vehicle is a 2003 Dodge Dakota with a 4.7-liter engine. The truck refused to start. When the gas pedal is pressed, the vehicle will start and run, but it will stall. Codes have been checked. P0509 was the result of this brainstorming session. I double-checked the wiring as well as the IAC. Everything appeared to be in order. I unhooked the IAC and cleared the code on the computer. When I disconnected the IAC, I received the error code P0508. My IAC is only equipped with two wires. 4 is not the correct number. P0123, P0122, P118, P0508, P0522 2009 PT Crusader codes P0123, P0122, P118, P0508, P0522 2009 PT Crusader codes P0123, P0122, P118, P0508, P0522 09 PT Crusader Please assist me. there is no commencement
- The check engine light is illuminated. Cruiser p0032, p0508, p0038 (PT Cruiser 2004). pt cruiser from 2004 (not turbo) 112,000miles Item Numbers: 0032, 0508, and 0038.
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OBD code reader works
The good news is that, after much frustration, I have finally managed to get my VAG COM (FTDI chip-based) code reader to function properly. From here on out, I’ll be attempting to fill out the higher-level OBD capabilities for the T4 ecu (which should be lot simpler now that someone has supplied a link to @cybernet’s wiki page for the T4e). The bad news is that I have a total of ten codes: Individual packets of the following form are returned by the OBD response: 72,107,16,67,X,X,X,X,X,X, Each pair of X and X (two bytes) together makes up a single check engine code.
the first code is 4 128: 00000100 10000000: the second code is 4 128: 00000100 10000000: -00 = P, 00 = 0, 0100 = 4, 1000 = 8, 0000 = 0-P0480 Fan 1 Control Circuit 33, 0000 = 0-P0480 Fan 1 Control Circuit 33, etc.
20 1 114: 00000001 20 1 114: 00000001 20 1 114: 00000001 20 1 114: 00000001 20 1 114: 00000001 20 1 114: 00000001 20 1 114: 00000001 20 1 114: 00000001 01110010: P0172 system is overloaded 20 It goes like this: 18.104.22.168.5 7 0.0.0.0 0 185.07: 00000101 00000111: P0507 Idle Air Control System RPM Greater Than Expected 35.
I’ll be inspecting my ground wires and harness as soon as possible to confirm this.
Is there something more going on with this miraculous cocktail?
Diagnostic Codes – Arctic Cat PANTERA 7000 2015 Operator’s Manual [Page 15]
Indicator for engine oil pressure, not engine oil level; nonetheless, if the level of the engine oil is too low, it may have an effect on the indicator’s reading. If the oil pressure is lost, the oil level should be checked. If the indication does not turn off or if the engine does not start, take the snowmobile to an authorized Arctic Cat Snowmobile dealer for repair or replacement. If the snowmobile is not covered by a warranty, this service is provided at the discretion and expense of the snowmobile owner.
- Fuel Level Indicator – The indicator will illuminate whenever there is insufficient fuel in the tank.
- If a code is shown while the engine is running, this indicates that the ECM is receiving input that is outside of the parameters that have been defined.
- If the snowmobile is not covered by a warranty, this service is provided at the discretion and expense of the snowmobile owner.
- 4The barometric pressure sensor may be open or short circuited.
- 6In the case of water temperature, open or short circuit – 7In the throttle position, open or short circuit the circuit.
- code 7000 Pantera Pantera 7000 Code P0031 O2 Heater Control Circuit has a low resistance.
- P0107 Low absolute pressure circuit in the manifold P0108 High absolute pressure circuit in the manifold P0112 Intake air temperature sensor circuit has a low voltage.
P0115 Engine coolant temperature sensor 1 circuit is a diagnostic code.
P0118 Engine coolant temperature sensor 1 circuit high P0118 Engine coolant temperature sensor 1 circuit high Sensor.sensor is a source of trouble.
P0122 Throttle position sensor circuit is not functioning properly.
Circuit for the oxygen sensor P0130 P0131 O2 sensor circuit has a low voltage.
P0171 The system is overly lean.
P0201 Injector circuit/open – cylinder 1P0202 Injector circuit/open – cylinder 2P0203 Injector circuit/open – cylinder 3P0217 Injector circuit/open – cylinder 1P0217 Injector circuit/open – cylinder 1P0217 Injector circuit/open – cylinder 1P0217 Injector circuit/open – cylinder 1 Overheating of the engine’s cooling system P0261 Cylinder 1 injector circuit has a low resistanceP0264 Cylinder 1 injector circuit has a high resistance P0267 Cylinder 2 injector circuit is underpowered.
P0268 Cylinder 3 injector circuit is underpowered.
P0523 The engine oil pressure sensor circuit is overloaded.
P0780 Shift Error is a kind of error.
P1686 Main relay circuit lowP1688 Reverse relay open circuitP1689 Reverse relay circuit lowP1691 Forward relay open circuitP1692 Forward relay circuit lowP1694 Headlight relay open circuitP1695 Headlight relay circuit lowP2228 Barometric pressure sensor A circuitlowP2228 Barometric pressure sensor B circuitlowP2228 Barometric pressure sensor C circuitlowP2228 Barometric pressure sensor D circuitlowP2228 Barometric pressure sensor E circuitlowP2228 Baro P2229 A circuit for the barometric pressure sensor is quite high.
Primary control circuit for the ignition coil (P2300) is low.
P2306 Ignition coil C primary control circuitlowU1000 P2306 Ignition coil C primary control circuitlowU1000 Vehicle that is not registered or is ineligible PINU1001 Vehicle is not registered, and lim-its are activated on the vehicle. U0155 Communication with the ECMTrouble11 has been lost.