Quick Answer: How Do You Troubleshoot A PCM?

What causes a PCM to fail?

PCMs typically fail for one of two reasons: voltage overloads (often due to a short in a solenoid or actuator circuit) or environmental factors (corrosion, thermal stress or vibration).

If water gets inside a PCM, it can short circuits and set up irreversible corrosion that ruins electronic connections..

How long does it take to replace PCM?

The process takes around about half an hour, but keep in mind that most auto-electricians charge you for at least one hour of work. PCM reprogramming is also one of the few times we’ll recommend a dealership over an independent mechanic.

Where is the PCM fuse located?

The fuse box is located on the passenger side next to the battery.

Can you reprogram a PCM?

Reprogramming a PCM requires a J2534 Pass Thru device. Only 2004 and newer vehicles can be reprogrammed. … To reprogram a PCM, the tool must comply with SAE Standard J2534-1. You can also use a J2534-2 pass thru tool that can reprogram other control modules as well as the PCM.

Can a bad PCM cause transmission problems?

For example, poor performance or unexplained drops in fuel economy or efficiency are often related to onboard car computer problems, or faulty ECU issues. A damaged ECU can cause problems when shifting gears in an automatic transmission, or cause sudden jerking or stopping that’s similar to transmission problems.

What does flashing a PCM mean?

Powertrain Control Module reflashingPowertrain Control Module reflashing is essentially a software upgrade. … You might hear the terms PCM programming, PCM reprogramming, PCM flash, or PCM reflash. Dealers or car repair shops might call it a PCM or ECM reprogramming service. They all refer to an upgrade of your PCM’s microchip.

How do I reset my PCM?

How Can I Reset the PCM on My Car?Open the hood of the vehicle.Disconnect the negative battery cable from the battery. Use a wrench to loosen the lock nut, and pull the cable off. This cuts the power to the PCM. Wait for five minutes. Reconnect the negative battery cable to the battery and close the hood of the vehicle. The PCM is now reset.

Will a bad PCM throw a code?

The PCM should give you a code for P0600 through P0606 indicating that the computer has a processor error. However, if the PCM is corrupt, then just like a desktop computer, there is no accessing anything and no codes are put out for the computer would have no way of sending a signal.

Can I use a junkyard PCM?

It wouldn’t run for more than two seconds. I took it all to the dealer and paid $84, and haven’t had a problem for 2,000 miles now. Shifts fine, fuel pump primes, engine light is off, it’s all good. The short answer in my experience is: no, you can not plug a junkyard PCM in without flashing it to your VIN.

Can a PCM cause misfire?

3 Answers. If PCM is bad it would give a random misfire,check the compression on the cylinder that is not firing,may have bad valve on it.

Is the PCM and ECM the same thing?

PCM (Powertrain Control Module) – This is a combined engine and transmission control unit which will provide management and correct function of the engine and transmission from one control unit. ECU (Engine Control Unit) / ECM (Engine Control Module) – This is an electronic control unit that manages the engine only.

How do I know if my ECM relay is bad?

Symptoms of a Bad or Failing ECM-Power RelayNo power when the key is inserted. One of the first symptoms of a problem with the ECM power relay is no power when the key is inserted. … Engine will not start. Another common symptom of a problem with the ECM power relay is an engine that will not start or turn over. … Battery drain or dead battery.

Why would a PCM need to be reprogrammed?

PCM Reprogramming is also necessary to change the engine idle speed, spark timing, fuel mixture or other emission control functions. PCM Reprogramming may be required to resolve a hot or cold starting issue, idle roughness, stalling, or an emissions failure.

What are the symptoms of a bad PCM?

A bad PCM can cause the vehicle to not have any engine management control. Without any control, the engine won’t be able to start at all. The engine might still be able to crank, which shows that the engine is working fine, but the computer is not sending the correct signals to start the engine.

How much does it cost to fix a PCM?

The PCM controls more than 100 factors in your car, and for that reason, is very important – and expensive. A typical pcm replacement cost comes to between $500 and $1,500 on average.

Will disconnecting battery reset PCM?

So, Disconnecting the car battery to reset the (PCM) on late model vehicles; can do more than just erase the keep alive memory. It can also erase vital learned information; that is absolutely necessary; for other modules to function normally.

How do you tell if your car’s computer is fried?

Usually a bad or failing ECU will produce a few key symptoms that can alert the driver of a potential issue.Check Engine Light comes on. An illuminated Check Engine Light is one possible symptom of a problem with the ECU. … Engine stalling or misfiring. … Engine performance issues. … Car not starting.