Electrical Issue 2004 Tahoe Z71

[bandroidx]

add a new symptom, today the heat got stuck on no matter what temp i set on the controls. next time i drove the car it worked normally.

 

[corvette744]

I would take it in and get it checked out,with the correct test equipment-or run it into a wall.It would drive me insane with all those problems.

 

[bandroidx]

I would take it in and get it checked out,with the correct test equipment-or run it into a wall.It would drive me insane with all those problems.

Im probably going to get a new body control module and try that before i bring it to the dealer. I havent been able to find anyone with a tech2 tool and its going to cost about the same to get a new BCM and have it programmed than it will to go to the dealer to have a diagnostic. if that doesnt fix the problem then I will get the diagnostic done. i personally think its the BCM, and if its not i will have a new one that i dont have to worry about moving forward.

 

[retiredsparky]

Did you say that you replaced the battery with a new one? I have found similar symptoms in other GM vehicles which were eliminated by replacing the battery.

I believe that GM's electronics are sensitive to poor quality power. Batteries can seem to work and test normally but can cause strange non-functional controls. I don't have any opinion about the actual reason this occasionally happens, but replacing the battery even if only a couple of years old may solve the issue if nothing else works.

Non working radios, mirrors, power seat controls, HVAC controls, transmission mis-shifts, gauges acting up, interior lighting malfunctioning are all things I have fixed by replacing a supposedly good battery. Not always a fix, but not at all uncommon.


Larry

 

[renderingrocks]

With your gauges going crazy, I would check the ground that is located next to the cam sensor. Its behind the intake on the passenger side of the engine. Follow the wire down, its tough to get at but you'll see it. If thats dirty, corroded, loose, etc, that will drive that cluster crazy. The other grounds that usually are a problem with this generation are the battery ground located under the driver side bumper area, and the ones underneath the car under where the driver sits. But with cluster issues, BCM, go for that engine ground I first mentioned. You can always move it to a better area.

 

[bandroidx]

I ended up buying a new BCM from Amazon and sending it to Gm-flash.com who flashed it for me and so far no issue after installing the new BCM except that I have my airbag light on and it says service air bag. the GM-flash.com guy said this is because I didnt send him my old one and I didnt time the 30 min relearn perfectly so I either need to do the 30 min relearn on my old BCM, then do it again on the new one or bring it to GM to get a 10min relearn done which will clear the airbag error. I am waiting to make sure the issues dont come back (to make sure the new BCM actually fixed my issue) before I bring it to the dealer. Unforunately I think they are going to charge me $100-$120 even though its a 10min procedure as they likely have a min 1 hour service charge.

I checked all the grounds before I replaced the BCM and all looked in really good condition.

 

[bandroidx]

well bad news, the BCM didnt fix the problem after all. After working great for over a week today the car started slowly like the battery was low and the guages stopped working again. I let the car charge the battery, then started it again at 12.5v but it didnt help. I also started the truck with a 12v battery attached to boost the power just to see if a battery issue was to blame but it didnt matter (not surprised since it measured 12.5v).

What happens is this. I turn the ignition to on, the check engine light turns on for a moment, its the only thing that lights up on the dash. I then start the car and the guages light up and the blinker indicators work fine but all the guages are dead at zero and dont move and none of the indicators work and the gear indicator and driver information screens are also dead.

 

[bandroidx]

I ordered a new dash cluter since this seems to be a common issue with my year, hopefully it fixes it, worse case I have a nice new dash cluster with working lights. mine half the lights are dead or dying

 

[bandroidx]

New dash cluster fixed my issues. I am going to keep the new BCM since i also had other weird issues.