So here's what's been happening. Every once in a while, I turn the key to start and nothing...no clicking just the instrument cluster lights up but engine will not crank. It's been going on for two years? It has done this first thing in the morning when it is cool and during a long trip in traffic in hot weather. There are no codes.
This is what I've done so far:

1. New start/run and crank relays
2. New ignition switch
3. New starter
4. New battery
5. Removed and cleaned engine to chassis ground. Also cleaned the ground next to the battery.

Any thoughts on where to look next?

 

did you test any voltage before shotgunning parts at it?

 

Yes…unfortunately all the voltages were what I would expect. The one item that appeared to be the culprit was the starter. It didn’t sound the same as in the past and it did stay engaged a couple of times after the engine started.
This is a very intermittent issue that has been going on for a couple of years.

 

Is there an anti theft system?

 

Not certain about the anti theft…how can I identify if it has one?

 

Did you buy it used? I'd suggest eliminating things such as the starter, can you jump across the solenoid see it it cranks?

 

I have a ‘15 3500, that had that off and on starting, and it turned out to be the PCM. I had eliminated the Starter, and Relays. About a month after I got it back….yep, the Run Start Relay went out, no biggie, but it was ouch on the PCM.

 

Lakeman, are you referring to the body control module under the dash or the ECM under the hood near the fuse box?

 

I went and pulled my Receipt, and they say “Found Theft Deterrent Feature Locked.” Replaced PCM and Reprogrammed 3 Keys…Installed SL-N-MODULE (03670-CT
it shows 3 HR = $450.00 then 1 HR @400.72 ( this later labor cost is shown with the Module.)

Possibly mountain Annie can decipher this and tell you.

Ron

 

Check your ignition key. Assuming its an OEM GM key if it has the small "+" sign on the key it has an encoded chip as part of the anti theft circuit. When this malfunctions, BCM will not tell the PCM to engage the starter solenoid. I have not had this problem on my express van however I have had it before on another GM vehicle. One thing easy to try is to shelf the key you are using and use the other key only. If you have no other key, have one cut at a GM dealer and program from your original then start using the new key exclusively and see if the problem persists.