What to do if your GMC Truck wont start?

No relearn is necessary. In this situation, the vehicle will start and run with no problem. If the vehicle won’t start, check your scan tool for a VTD (Vehicle Theft Deterrent) Fail-Enable Mode trouble code, or if the security light on the dash is illuminated.

How does the PCM control the idle speed?

The PCM monitors idle speed and operates a solenoid or small electric motor to move a valve that regulates airflow through the air bypass circuit. If the ISC valve is gummed up with fuel varnish or dirt, it may stick, preventing the engine from maintaining the proper idle speed when the throttle closes.

Why is my PCM not working in my car?

This generally happens because of a faulty sensor, or because water has damaged some of the circuits in your car’s PCM or TCM. If your automatic transmission vehicle isn’t shifting normally, take it to a mechanic immediately. A failed PCM or TCM can cause the car to get stuck in gear, which can be a serious safety issue.

How long should I Leave my ECM at idle?

You will want to leave your vehicle at idle for at least 10 minutes which will give your ECM enough time to “learn” any new modifications installed on your vehicle.

Can a car stall with a bad throttle position sensor?

The engine can stall for no reason and without any warning. This happens when the TPS gives incorrect information to the ECM. The engine can stall at high speed, at low speed, or even at idle. A faulty throttle position sensor will not let your car accelerate normally. Though this doesn’t happen all the time.

How does the throttle position sensor work on a GM Truck?

Like the majority of throttle position sensors on modern fuel injected cars and trucks nowadays, the GM TPS is a three wire sensor. Each wire provides a specific type of signal to the TPS or to the PCM (Powertrain Control Module=Fuel Injection Computer). Below are the circuit descriptions of each:

What happens when you disconnect the transmission module?

The transmission may not feel the same; until the (PCM) or transmission control module, relearns the shift adjustments. The affected module may; prevent the (ABS) or airbag systems from working.

How can I Reset my GMC Yukon shift?

I pulled back in and put it in park and tried to drive and it failed again. I disconnected the batteries and reset the system and it ran great like it used to. A week later the same thing happened again. The same problem as well followed with the rough shifting as well. Then a couple days ago it did it to me again.

How to reset the computer on a GMC Truck?

Click to expand… Click to expand… Click to expand… Click to expand… Click to expand… This system consists of: the Powertrain Control Module (ECM or PCM), Body Control Module (BCM) or Passkey theft deterrent module, and the ignition lock and key. In most cases, the theft deterrent duties are handled by a Passkey module.

Why is my Duramax diesel engine not working?

The trucks computer keeps track of how much fuel needs to be added or subtracted from each individual cylinder to make the engine run smoothly, and this value is called the balance rate. If one cylinder is contributing too much or not as much as the rest, the cause is usually a bad injector and the cure is a replacement.