2002 Tahoe Electrical Issues

[Blackedout02]

My 2002 Tahoe has had an intermittent turned permanent no start.
Crank no start issue.
When I turn the key on the right turn signal gets power through the fuel pump relay (same when cranking), the service 4WD light is on, and the rear wiper comes on; both for no reason. When the headlights are on it turns on the ABS light , Park Brake light, turn signal, and fuel reads empty. Headlights off and those go away but still no start.
There are no codes relating to the issue in the system

I have inspected as much wiring as i can see (no visible damage or shorting wires), I have now replaced: BCM, Fuse box, coolant temp sensor, ignition switch and wiring, battery-engine ground cable, and fuel pump. I’ve also cleaned and verified the ground to the back of the cylinder head and under the driver door.

What else do I need to check or replace to get this truck going again?

 

[S33k3r]

There is a ground on the driver's side to check as well, the positive lead from the alternator to the fuse box (this line is known to look good, but have rusted internally, separating a lot of the little wires); it could also be a short in a wire or wires in your dash. I'd check the wires in the steering wheel and/or behind it. You also may have a stowaway, or previously had a stowaway. Check for evidence of rodents (droppings, fur, nests, chewed wires), especially in and around the fuse box under the hood, and in your dash. May have evidence in your floor console, if you have one.

Good luck!

 

[Blackedout02]

There is a ground on the driver's side to check as well, the positive lead from the alternator to the fuse box (this line is known to look good, but have rusted internally, separating a lot of the little wires); it could also be a short in a wire or wires in your dash. I'd check the wires in the steering wheel and/or behind it. You also may have a stowaway, or previously had a stowaway. Check for evidence of rodents (droppings, fur, nests, chewed wires), especially in and around the fuse box under the hood, and in your dash. May have evidence in your floor console, if you have one.

Good luck!

There was a small amount of debris (maybe beginnings of a nest) under the fuse box but no wires looked damaged when I replaced it. All of the driver side dash wiring looks good now. I replaced the ignition switch which got rid of the poorly installed and non-functional remote start and security bypass modules. Now most of the wires are fresh. I’ve been told there’s a ground next to the cluster by the A-Pillar but I have yet to find it.

 

[S33k3r]

We had an issue, recently, where we had water intrusion at the ECU. This resulted in the wiring coming into the ECU becoming rusting and brittle, with some of the wires actually breaking. So that's something else you can look into.

 

[Blackedout02]

Already checked ECM wiring and connections. All look brand new. No visible water intrusion

 

[S33k3r]

Have you checked the body control module? I'm guessing in the dark, here. But figure it is worth a look. Otherwise you are back to chasing wires.

 

[rockola1971]

Pull connectors at PCM and check for green/blue corrosion.

 

[Blackedout02]

Have you checked the body control module? I'm guessing in the dark, here. But figure it is worth a look. Otherwise you are back to chasing wires.

Already tried replacing it and no change. I’ve looked at as many wires as I can and I see nothing broken or exposed

 

[Blackedout02]

Pull connectors at PCM and check for green/blue corrosion.

Already checked and everything looks clean

 

[Fless]

Basic test for spark on both banks.

Fuel pressure test at the rail. In addition to verifying fuel pressure, are the plugs getting wet?

Use a noid light to see if the injectors are getting pulsed.

Also, there is a small ground on the passenger side firewall behind the back of the head. I think this comes from a harness and may make the ground for the injector harness, but the noid light test will verify. Could make a temporary injector ground from battery negative to the ground on the fuel rail harness.