Help with Troubleshooting Problem with Chevy SUT

[rick-l]

Originally Posted by kaisen

Rick hates GM, btw

That would be true based on personal experience as a vehicle owner and investor.

I grew up in Minneapolis so I know where you are coming from.

[ErVikingo]

Boosted, Thanks for the info.

I'll start by checking that ground and then setting aside circuits.

I spent some hours looking over the wire spaghetti under the dash. Nothing looks frayed or with heat damage.

The engine compartment is very clean but I gather that unless I lift the fuse box I won't know for sure. Rodents are not a big problem here.

Not sure if related (or if my local station is selling bad gas) but the engine started knocking/pinging upon hard acceleration. This has never happened in 9 years of driving.

The search continues...... Look forward to any other ideas. THANKS!

[kaisen]

Originally Posted by ErVikingo

Not sure if related (or if my local station is selling bad gas) but the engine started knocking/pinging upon hard acceleration. This has never happened in 9 years of driving.

But no "Check Engine" lights or codes from the knocking/pinging?

[ErVikingo]

No check engine light. Hammer it and you hear it.

Only thing I found out when looking underdash is that the brake controller (Prodigy) is showing a bad connection to the trailer when I have nothing connected to the truck. FYI, the wiring harness to the Prodigy is the factory supplied one.

[kaisen]

Originally Posted by ErVikingo

No check engine light. Hammer it and you hear it.

Until you have a light, it's not really an issue. Likely bad gas. If it still does it after your next fill, think more about it.

Only thing I found out when looking underdash is that the brake controller (Prodigy) is showing a bad connection to the trailer when I have nothing connected to the truck. FYI, the wiring harness to the Prodigy is the factory supplied one.

Try disconnecting/unplugging your Prodigy controller. It's all on the same circuit in terms of feedback. If you no longer have the issue, the controller itself could be the culprit.

Just a thought

[ErVikingo]

OK Thanks!

[boosted 89]

Usually brake controllers will give you a bad connection at trailer reading only because there is no load, but it wouldn't hurt to dissconnect it at the small break
out box by the brake pedal.
It looks as though the only circuits that fuse powers is the PRNDL switch on the side of the trans(which may water instrusion casuing a short to ground) the
a/c compressor relay (which you can just remove) instrumnet panel cluster(which I know has been replaced but it doesn't mean it can't be faulty) and the turn signal switch. Luckily it doesn't run a lot of circuits so you can eliminate stuff one by one to try and locate the fault. I have seen replaced(mostly repaired by aftermarket company)clusters fault so it wouldn't be the first time. I'd be more inclined to look at the PRNDL switch for fault only because the fuse only blows when cranking.

Chris

[ErVikingo]

argh, just got towed to dealership. Left me stranded at gas station. Turns but won't start. DIC reads "Unknown Driver". All accessories are dead too.

I figure security system but alarm did not go off. No blown fuses this time.

Frustrating.........

[kaisen]

Originally Posted by ErVikingo

argh, just got towed to dealership. Left me stranded at gas station. Turns but won't start. DIC reads "Unknown Driver". All accessories are dead too.

I figure security system but alarm did not go off. No blown fuses this time.

Frustrating.........

Unknown driver means that it doesn't recognize the PATS code in the key. Try the other key, just to be sure that the key you just tried didn't lose or break its RFID chip

[ErVikingo]

2nd key + key fob did not work either......

Service writer just called. They diagnosed back to "the computer" (could not say which) and found some frayed wires and did a "reset".

I can see that they are not sure as he said that a note is in the record that if the problem returns, I won't be charged for diagnosis.

We'll see.

THANKS Eric!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[kaisen]

If neither work, then the PATS system isn't working correctly.... I can't recall whether that's the Body Control Module (BCM) or Powertrain Control Module (PCM)

Hopefully this is the end of it

[ErVikingo]

Eric,

I guess they might have found something! No communication to any module.

Bulletin 03-08-50-014A: reroute harness under seat and under battery tray. Do hard reset on all computers.

So far so good!