No start?

TRMISOK

MEMBER
2000 GMC YUKON
5.7L
V8
2WD
AUTOMATIC
200,000 MILES

I have a 2 part Question.
1. Does 2000 GMC Yukon have a chip key?
2. Can I replace the PCM with a used PCM without creating some kind of security or key fob issues?

As of now, during troubleshooting, I'm not getting any signal to the coil module or the coil. And the crankshaft position signal stays constantly at 5 volts reguardless of cranking the engine or not.

PS, could Crankshaft position be bad?
The reason I ask is the positive signal at the sensor is the same source line voltage as the coil and coil module. (12 volts) not the PCM 5 volt.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,254 POSTS

Hi,

First, yes there is a sensor in both the key and ignition cylinder. If you replace the PCM with a used one, you need to be careful to make sure it is the same part number. It will likely need to be programmed to your vehicle.

Note that the security light will stay on if there is an immobilizer issue. I you suspect that is the case, turn the key to the run position and allow it to remain on for approximately 10 minutes. If the security light turns off, see if it will start. That is the override procedure.

Now, here is what I need to know. (I am basing this on a 5.3L V8. The 5.7L is only listed in the 4wd Denali. Please confirm that for me.

If you have a live data scan tool, see if there is an RPM signal when cranking the vehicle. If you don't have a live data scan tool, pay attention to the tachometer to see if it moves a bit.

Take a look through this link and let me know if anything mirrors what you experienced:

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

Let me know.

Joe