Silver08

I have an 08 Silverado 4x4 LT 5.3 Flexfuel that I have owned for two years. Starting last September, I have had issues with the clock resetting, the AC was blowing hot out one side(air door actuator?) and after turning the truck off, I was unable to turn it back on. There was no power to locks, ignition, or gauges.

I have had the power issues maybe 4 times since then. On a couple of these occasions, I have attempted to jump start the truck. I left the cables hooked up for maybe ten minutes one time before it fired. A couple other times, I just let it sit for a few minutes and got it to start. On several occasions, I had my radio clock reset to 1200, my instrument panel indicated the stabilitrak was off, and my air conditioning blowing hot air out of just some of the vents. The A/C will usually reset after turning the truck off and on a few times.

Most recently, I had the power issue and also my front door control panels went crazy with clicking and buzzing sounds for about 15 minutes. I could take the key out of the ignition and the sounds would continue. If I put the key back in the ignition and turned, the sounds would stop temporarily before they started going again. At this point, I tried jiggling the positive and negative cables on my battery, got back in the truck and it fired right up.

Through these several months, I have had the battery, starter, alternator, mega fuse, battery connections, and grounds check out by multiple mechanics. Everything has checked out. The battery cables appear to be snug and are showing no corrosion. I noticed another post on this forum with similar issues and recommended changing out the positive cable but my local GM service center didn't see any problems with it. I have also had the following similar issues but they appeared to not be the issue either. Does anyone have any experience with this?

I have found while searching the internet a TSB that mentions the following:
#PIT4816: Multiple Electrical Concerns With DTC C0900 - keywords battery c/k cable clock crank cycle door dimming flicker gage gauge gmc hvac inop inoperative instrument ipc lock no panel power radio stall - (Feb 27, 2009)


Subject: Multiple Electrical Concerns With DTC C0900
Models: 2007 -2009 Cadillac Escalade, ESV, EXT

2007-2009 Chevrolet Avalanche, Silverado, Suburban, Tahoe

2007-2009 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon Denali XL

(Equipped with Gasoline Engines)

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:

Some customer may experience one or all of the following concerns.
1) Intermittent No Crank or No Vehicle Power ( The customer may get the impression that the vehicle actually has a dead battery )
2) Volt gauge fluctuates, and seems to decrease when a high load accessory is turned on ie.. headlamps, wipers
3) IPC backlighting flickers or IPC goes blank
4) Diagnostic Code: B1325 set in several modules followed with a Dtc: C0900 set in the EBCM.
5) Radio clock resets
6) Intermittent Stall
7) Hvac temperature actuator defaults to hot
8) Door locks cycle
Recommendation/Instructions:

If you experience one or all of the following concerns and a cause for the concern can't be identified, please check the following items:
1) Remove the 175 amp Mega fuse and inspect for arcing, if any type of arcing is found replace the effected components.
2) When re-installing the 175 amp Mega fuse, torque fasteners that attach the mega fuse to the positive cables to specification in SI.
3) Check the voltage drop reading on the positive and negative battery cables. The voltage drop should be performed with the fuel injectors disabled and while cranking the engine. The voltage drop should not exceed 200 mV. If the voltage drop is above 200 mV, replaced the effected cable.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.