2008 Silverado Electrical Issue

crunchnd · August 19, 2012

I was driving my 2008 Silverado (42K miles) this weekend. I had the cruise set going down the highway and as soon as I used my turn signal to pull out, my cruise kicked out. I was driving about 100 miles and was able to repeat this every single time. First though through my head is that there is an electrical short coming from the multi-function stalk. So next thing I tried is pulling on the stalk to turn on the high beam and WHOA...my entire electrical system appeared to re-boot. Every light in the dash turn on, I saw a Stabilitrak Off flash, Airbag light flashed, my clock on my radio reset to 12:00, the HVAC reset. So after all these lights went off, I got to my destination, shut the truck off, hoping the computer may have needed to reset and attempted to start it again. I turned the key on and nothing, no power. Key cycled it a few times and still no power. Waited a minute, and then it started fine. I also have noticed since this happened that when I turn my key off, my radio and other accessories immmediately shut down, instead of staying on until I open the driver door. I have driven a it a few times over the weekend, and I keep noticing that the clock and HVAC continue to reset themselves intermittently. Also, the radio will cut out briefly when I tap the brakes with cruise on so it makes me wonder if there is a short somewhere in the harness in the dash.

I have noticed twice during the past two weeks that my truck hasn't started using the factory remote start and the day before this bizarre behavior, when I went to start the truck, it gave me a security system type error on the cluster when I attempted to crank it. The second time it started fine.

I came across TSB # 09-08-68-001, but that does not seem as bad as the issue I am experiencing. I haven't checked for a bad ground cable yet, but thought I would see if anyone has experienced anything similar. The battery was replaced back in December.

mdauwald · August 19, 2012

I'm not sure if this can apply to our trucks because I haven't had to change a tail light bulb yet. One time in another vehicle I experienced similar havoc that was due to both filiments in a 1157 bulb fusing together. I had changed many 1157 bulbs over the years but never saw the filiments fuse together. It caused all kinds of problems with lights and signals. I'd look to see if our tailights share a single bulb for tail light and brake light. Just a wild guess

crunchnd · August 20, 2012

I came across this on a different forum and describes my issue almost exactly. The only thing that confuses me is that the TSB number is in a different format than what i am used to seeing (ie. XX-XX-XX-XXXX). Is this something the dealer will recognize if I bring it in to them?

#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.

white07gmc · August 20, 2012

I have this same problem. I was driving down the road and I used my blinker when I changed lanes and my door locks started locking and unlocking and my ISP went CRAZY. freaked me out something fierce because I was going 80 on I95. I checked my batter terminals and found a shit load of corrosion on the negative terminal so I cleaned it with COKE and I have only experienced it once since then. I think I need to replace my Ground cable. It's weird because I always thought the Ground cable was terminated on the frame of the vehicle but mine is terminated on the alternator.

one more thing. Where is the 175 amp Mega fuse located?

VT_Z71 · August 20, 2012

Check your battery for corrosion. If it all looks good, get it tested. The least little change in electrical current from the battery causes the GMT-900 electrical sytem to go all kind of haywire.

After fixing all of that, getting a new Optima Yellow Top and still having issues similar to what you described, I went to the dealer thinking I had a bad ground somewhere. Turns out, I had a crimped positive battery cable that was causing all of the problems. Replaced the cable under warranty and nothing more to report. By the way, I believe there is a GM TSB out for this issue on certain model years of the GMT-900.

pjp · August 21, 2012

I had a similar issue with my 08, but I kept noticing that the A/C would just quit. Then it progressed to a limp mode out of the blue and had it towed to the dealer. The first dealer couldn't find anything and sent me on the way. A week later it happened again and had it towed to another dealer. They ended up changing out the whole main electrical box (with the relays) on the drivers side under the hood. It's been 2 years now and 25,000 miles and no more problems.

Tycu · December 14, 2013

I had silmiar symptoms listed in this thread, not starting with remote starter...sometimes, thinking there was a battery issue. I took my truck to dealer and they load checked the battery. It failed and was replaced.

After a week or so the symptoms actually got worse, clock resetting, instrutment back lite flickering, Stabili-trac going off, etc. After reading this thread I checked the battery connections and found that the postive lead coming off the battery going to the 175 Mega fuse was not tight at the fuse(located on the firewall near the battery), and I was able to wiggle it loose. As an Indusrtrial Electrician, I know the importance of tight electrical connections. This post, lug and nut did not have a lock nut on it, so I added one to keep this connection tight in the future.

Added this reply after finding this problem, and will reply again if this did not clear the isssues I was having.

northside1908 · December 14, 2013

this summer I went to start my truck in the morning and got nothing. Every light on dash on, cd's turning around, door locks going crazy. After work put charger on it and after a while it started as normal, no lights on dash. I went to auto zone to have battery checked out (their battery) everything ok. All summer I kept jump box in truck just in case. Fast forward to Nov 27 . I go to start truck , but before that I put in the range technology v4 disabler that I have been using and again all lights on dash come on but it starts this time. I didn't have the range when this happened in summer. Called dealer and he said it sounded like a battery problem with all the lights on dash going on. Again off to auto zone, this time after I restarted truck only check engine stayed on. Battery was checked out as good but I had a bunch of codes. Next week off to dealer (gm extend war) where they found that the neg battery cable was "355-ma out of specs". Service writer said one of the techs son had the same thing on a Tahoe he has and they think this was the fix, as it has not happened again. There is a post on here (believe the range tech. thread) where somebody had same problem as me and using the range. This person went to dealer but never came back to say what happened. I hope the range tech v4 disabler is not the problem because man with that thing in truck runs way better.

birdizzo · March 7, 2014

I had a similar issue also. I have a new battery that I replaced in early November, it was 5 years old, the original.

Early Feburary during the bitter cold here in WI, I had a 1/4 tank of gas, -15 degrees, and when I tried to start the Suburban it just freaked out, dashboard lights flashed for a moment and no crank. 3 or 4 tries later I got the same results. I pulled the Range Tech V4 Disabler I had installed in the ODB port, tried cranking again and it worked.... I did hear a noise this time in the rear that sounded like a Fuel pump running.

I have not put the v4 disabler back since this happend, and I have not seen it happen again.

I'm going to inspect my 175 amp Fuse this weekend.

this summer I went to start my truck in the morning and got nothing. Every light on dash on, cd's turning around, door locks going crazy. After work put charger on it and after a while it started as normal, no lights on dash. I went to auto zone to have battery checked out (their battery) everything ok. All summer I kept jump box in truck just in case. Fast forward to Nov 27 . I go to start truck , but before that I put in the range technology v4 disabler that I have been using and again all lights on dash come on but it starts this time. I didn't have the range when this happened in summer. Called dealer and he said it sounded like a battery problem with all the lights on dash going on. Again off to auto zone, this time after I restarted truck only check engine stayed on. Battery was checked out as good but I had a bunch of codes. Next week off to dealer (gm extend war) where they found that the neg battery cable was "355-ma out of specs". Service writer said one of the techs son had the same thing on a Tahoe he has and they think this was the fix, as it has not happened again. There is a post on here (believe the range tech. thread) where somebody had same problem as me and using the range. This person went to dealer but never came back to say what happened. I hope the range tech v4 disabler is not the problem because man with that thing in truck runs way better.

GMCustomerService · March 8, 2014

birdizzo,

Hi! I understand that you are looking to resolve this issue yourself and I might not be able to provide much in the way of do-it-yourself information. If you find that you are unable to resolve this yourself and may have some lingering concerns, please contact me via private message.

Jennifer T.

GM Customer Care

Sir Dan · March 9, 2014

Sounds like a battery or battery cable issue to me.

saxdogg · March 29, 2014

Search for all the posts on this already. You'll need to clean up some grounds on the body as well if you want to be thorough. I haven't seen prob again since cleaning every electrical connect from the battery I could find.

northside1908 · March 29, 2014

I haven't had any issues since dealer replaced the ground cable. My range has been plugged in just about the whole time. I must admit I cross my fingers when I go to start . My truck is in my unheated garage and started every time this winter even after sitting for 3/4 days. Oh and it was cold this year in Chicago . Your truck did the same thing as mine but I didn't have a range at that time. The second time I had trouble the truck started but every light on dash was on; this was with the range in. I would look into that neg battery cable. It's not that its loose but it is out of spec. as far as resistance. That's what my service ticket said.

do you have an update on this ?

Schmitter · May 5, 2014

I have a similar issue with my 2007 Silverado HD (New Body Style). Mine is the basic truck with plastic floors, just power windows and door locks. No cruise or keyless entry or fancy mirrors. When I drive down the highway and use the turn signal as legally required, the radio shuts off for a second and reboots. Sometimes it only happens once, sometimes more than once. Sometimes it will do it when I tap the brakes. This wouldn't really bother me, but when I get to my destination, and turn the truck off, it is as if the battery is dead, so I make sure the windows are up before I turn the truck off. A code reader says "no battery voltage". If I turn the key, it will send the tach to bounce negative numbers a couple of times, but I can't start the truck. The only way I can fix it is to disconnect the negative battery terminal and reconnect it. The truck will then run normally for a random amount of time before it happens again. Sometimes the same week, sometimes the same month and sometimes it will skip a month without acting up. I have had it to the dealer, and they cleaned the ground and wanted to keep the truck until it happened again. The problem is that once I disconnect the ground to get the truck to run, the problem goes away for longer than I am willing to be without my truck. If they cleaned the ground, would that mean that they checked for voltage drop?

truckin720 · April 20, 2015

I have a very similar issue with my 2008 Sierra SLT as the original poster. It is an intermittent thing, but it seems to occur when I have all my friends in the truck on a road trip, not when I'm just driving around town on my own. I've taken it to the dealer twice, and they replaced the ground cable, but it's still occurring.

Is there anything that I can do to fix it permanently? Anyone have any luck?