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Chevy Silverado and GMC Sierra Electrical and Computer Questions



  • ryan2274ryan2274 Posts: 2
    I'm dealing with the same problem. I have a 2007 1/2 ton GMC Sierra w/the VortecMax(6.0). Started having minor issues just like yours about a year ago but truck always restarted. Went to a local Chevy dealer and they said it was a ground. Truck ran fine for a while then slowly started doing the same thing until truck wouldn't start. Turn the key and lights(interior and exterior), radio, windows and locks, fuel pump, and the lights where the gauges are(DIC) would all work. I could also shift into gear. Unfortunetly the none of the gauges(fuel, oil, temp etc.) would not work and could not start the truck. Bought a new battery, still nothing. Had a local mechanic(non dealer garage) check every fuse, every ground, found nothing. After 3 days and him arguing with the Chevy dealership, he traced the problem to be in the BCM. So with the new battery installed he took his personal computer and cleared the codes. Then he went through a BCM restart. And that consist of turning key on waiting 14 minutes, taking key out(very important, take key out). He got this info from a friend in Texas, and i may not have all the steps correct. I will get back to you on this. Did this process 3 times and truck has run perfect every since. Truck will run normal until the battery runs down(which I know eventually will in time) or I have to disconnect a the battery cables(which I know I will at some point in the future). Long story short, truck will run as intended until one of the two happens. This is a temp fix, guess I just need to replace the BCM. Don't know what caused this to happen, wish I did. Sad thing is the Chevy garage is just gonna temp fix it for ya and send you on your merry way, and of course charge you, and of course not tell you anything so you can come back and spend some more of your hard earned money. Hope this helps and if you have any updates let me know.
  • did this ever get resolved...i have an 09 with the EXACT same issue and it is freaking me out. I cant find anything to really triggers it and it scares me to drive the truck.

    i took it to the dealer and they cant find anything and said bring it back while its acting up....which is hard to do when i cant really drive the thing while its going crazy....

    just this morning i was leaving and everything was acting weird when i hit the window switch so i pulled over and turned off the then was DEAD on the hwy for about a min and then everything came back on. ive had the crazy door locks going on and off and the downshifting as well as the stabilitrac turning off and on. I also get to where my AC is acting crazy and blows hot air on one side and cold on the other, again if i turn the truck on and off it all works correctly again.
  • '09 Silverado LT Crew Cab

    For me, it was a bad megafuse and new battery cables to fix. This should be a recall item but no help from GM other than the cursory response to my post - they didn't respond to my emails or follow up with my dealer. I do have video of the events including massive downshifting at highway speeds, cycling of ABS and traction control warnings, and even proof the passenger airbag light cycles. To me, it would seem this is a perfect storm and fatality waiting to happen - and one that GM is obviously aware of given their responses to many a post in these forums. Someday a lawyer will salivate over my footage.

    Now, a year later, still no issues - however, I now have power lock issues i believe are a result of the multiple lock/unlock cycles during the events.
  • jzblastjzblast Posts: 1
    I had a four door, 2011 Chevy Silverado that caught fire while driving. I have been spending the last two years to get compensated by Chevy. The concept of the fire was never determined, but in my opinion it was a short circuit in the fuel pump. It did short out the harness when the fire started.
  • obyoneobyone Posts: 8,054
    Was the damages paid for by your insurance company? Isn't up to them and their attorneys to go after GM if a defect is noted in the investigation. The insurance companies have the resources and the deep pockets to go after GM if their investigation indicated a flaw in design or manufacturing.

    Your quest, and you are entitled to pursue, may be a futile effort. As you indicated that the cause of the fire was never substantiated. It is unfortunate.
  • I recently bought a used 2006 silverado 1500. While I was checking things out I noticed that the BACKUP lights didn't come on in reverse, I checked thefuses and they are all OK I need to know if some one has had a simular problem and what could be wrong, I've check the switch and it seems to be working , this switch also controls the neutral and park start, it is rather hard to tell which one is for the BU lights and which is for the start funtion, I have a problem with the CARGO light also when the button is pushed to turn the light on the little light on the dash comes on telling me the light is on but it is lying, I have cheched every thing in this circuit also and it goes to the BCM, as does the BU lights. Does anyone know for sure if the BCMcontrols these 2 items are is it just a convient place for GM to run these wires to.
  • splinter8splinter8 Posts: 1
    I have a 2003 GMC. Recently the battery is being drained. I hooked up an ammeter and with ignition off there is a 15 amp draw on the battery which lasts for several seconds and then drops to 5 amps. This continues until the battery is dead. I can something happening inside the passenger door. Any ideas would be appreciated. Thx
  • cmnorthcmnorth Posts: 2
    GMC Sierra 1500 5.3 L - Charging system shuts down when towing and RPM over 2000. Inspected at dealer and found no issues. We have tried turning off the AFM system, replaced the alternator and am now looking at replacing the 5 year old battery as a temporary fix. Has any one had this issue and been able to resolve it?
  • bigman55434bigman55434 Posts: 22
    edited July 2013
    I have a 2013 Sierra 1500 with the 5.3L. Today, when backing into a parking space, my backup sensors started beeping like normal, then I put the truck in park. Backup beepers still beeping rapidly. Then I shut the truck off and took out the keys. Backup beepers still beeping rapidly. I opened the door, got out, shut the door, and locked it. Still beeping. I got back in the truck, restarted it, then shut the truck off again. They stopped beeping. I checked the sensors for dirt or obstructions. Nothing. WTF.
  • gmcustsvcgmcustsvc Posts: 4,251
    Hey bigman55434,

    You're still within your warranty. If this happens again or is a continued concern, have your dealership check into it.

    Amber N.
    GM Customer Care
  • lromjuelromjue Posts: 2
    Wshield washer stopped working. Pump motor runs but only makes loud SQUEELING noise. No water to Wshield. I guess the motor should be replaced.

    How do I get this fix? Can I do it myself. NE trouble shooting to be done first.

    Thanks, larry
  • Thanks Amber. After owning several newer GMC trucks, I have come to expect occasional weird electrical or computer related issues. These trucks are so dependent on computers, that I swear they "lock up" once in a while and need to be "rebooted" by restarting the truck. Like the time I backed out of my driveway, put the truck in drive, and it went nowhere. No throttle, no forward, no reverse, nothing. I had to restart the truck and then operation was normal again. This was on my 2011 Sierra 1500. Can we go back to the days of no computers in vehicles?
  • gmcustsvcgmcustsvc Posts: 4,251

    That is very strange what happened to your '11 Sierra. Computers in vehicles however is "the world we live in". If you happen to have any other concerns or just need to run an issue by me, do not hesitate to do so.

    Amber N.
    GM Customer Care
  • Yes, I agree that computers are a necessity in the world we live in. I just wish that GM software engineers would spend a little more time debugging their software. It is a little disconcerting at times when you know you are driving a vehicle powered by the equivalent of Windows Vista.
  • shopdog97shopdog97 Posts: 160
    A good friend of mine has a 2003 Silverado with the 5.3 V-8 and the other morning his check engine light came on for what he says is the first time and he bought the truck new, only has a little over 60K on it now. I used my code scanner and found 2 codes set. One is PO446 for which the explanation given is "Evaporative Emission Control System Vent Control Circuit Malfunction", and the other is PO452- "Evaporative Emission Control System Pressure Sensor Low Input". Is there anyone who has had these codes come up? What was/is the solution? Where is the location of these components in question? He says the truck runs just fine in his opinion, where I feel a slightly rough running engine. He told me when I asked him if he ever had the truck tuned up and he said NO! Original plugs and wires still in there after 10 years? Anyway if anyone can make a suggestion on this issue, I'd deeply appreciate it. Thanks!!
  • denhamdenham Posts: 76
    The vent control valve may stick open or closed when the computer cycles
    when engine is started. This control valve is at the fuel tank rear of the fuel inlet, and a bit difficult getting at. I have had this problem and it is because of dirt, dust and age. I have removed and cleaned a number of these after the customer has done spent big bucks and the light come back on!
  • chzzzitchzzzit Posts: 2
    I have a 2011 GMC Sierra 3500HD and I am having trouble with the headlights. They won't come on. I changed the bulbs, fuse and the switch. My marker lights and high beams still work. My headlights do not. Any ideas?
  • I had a very similar problem with my 2001 gmc sierra 2500. First signs of a problem was intermittent stalling. After a long drive all the gauges went haywire a couple of times. To get home I had to constantly feed it gas with my right foot and brake with my left. Took some advice from this site that the problem was in the ignition switch and it was. I have a repair manual for my truck and changed it myself. Saving $400-$500 bucks. Remove the old switch and the attached wiring harnesses and bring them with you as you may have several types to choose from depending on the number of pins yours has. The number of pins is really the number of wires leading to the module that has to be unbolted to be removed. Definitely buy a repair manual with pictures. Had some problems getting it to turn over after reinstalling everything. There is a trick to installing lock cylinder(found on Autozone repair site). When reinstalling ignition switch into lock cylinder prep the cylinder by sticking screwdriver into cylinder hole(in side of column) and turn internal latch clockwise and let it snap back(like the key would when starting) then seat the new switch in place. This little tip took me two hours to figure out. The rest was fairly easy. disconnect negative cable at all times except when trying to turn over engine. hope this helps.
  • lt_dlt_d Posts: 1
    I have a 2000 Chevy Silverado Z-71 5.3 litre. I've been having an intermittent problem with the dash lights blinking and when this occurs then the truck won't idle without pressing the accelerator. When this first started it was only the 4wd indicator lights that would all light up and blink. The last time this happened the 4wd indicator lights were blinking, the park brake light blinked, the abs light light blinked etc.. , and about every five seconds I would hear a click and all the gauges would fall to zero and then another click and they would work again. This problem only occurs at start up and when it happens then the truck will not idle without pressing the accelerator, and eventually the truck won't start again even when pressing the accelerator. I can disconnect the battery and then reconnect and it clears the problem. It happens randomly and usually works fine for weeks before it happens again.

    I thought that it might be a bad ground. However, since I can disconnect/reconnect the battery and it clears out the problem, I'm thinking it may be a computer related problem. Has anyone else seen this problem or know what I should check? Thanks in advance for any suggestions.
  • Hey all you out there. What do you think about a Dealer putting in 12 Qt of oil in in your 2013 Silverado 5.3 with 5000 miles on it and you drive it almost 40 miles before you see all the smoke coming out the tail pipe. How much damage did it do to my motor.
  • I own an '07 Silverado and about once per week when I am starting from a complete stop the transmission stays in low gear and the speedometer stays on "0" (even though the truck is moving). I have to come to a complete stop, nothing else, then everything works fine for another week or two. You never know when this is going to happen, but it has been going on for months now. I left with a local Chevy dealer for a week and they drove it, checked everything, and could find nothing wrong. Of course, as soon as I picked the truck back up it happened again that same day. It has to be some sort of electrical problem, but no one can figure it out. Any suggestions or similar problems to guide me in the right direction?
  • Just bought a 2006 Silverado 4.8, 2wd 1500.

    All of a sudden Saturday night, all 4 little gauges quit, and the ABS, Seat belt, and Battery lights came on. The power windows and interior lights with the door open also quit at the same time.

    This morning I cleaned the ground on the frame under the driver door and on the front driver side under the head lights.

    Anything else I can check? Is it the Dash? Is it the BCM? Is it still a ground?

    I have mechanical skills, just need to know where to look!!

  • nschevdrivernschevdriver New Glasgow NSPosts: 1
    I recently encountered the problem with the truck going bonkers and all lights on the dash lighting up, door locks going on their own and vehicle down shifting, then won't start at all (as if battery dead). Dealer replaced trailer brake and fuel pump modules. That solved issue for a few hours and then same issue and had to get towed for the 2nd time. I had a mechanic clean all the grounding points on the frame and the cab mount and so far there hasn't been an issue. As mentioned in a previous post, the ground on the frame under the driver's door was in poor shape and needed cleaned and tightened up. Crossing my fingers so far so good!
  • king80king80 Posts: 1
    My 2001 GMC light is on code reader at Auto Zone says misfire on coil1,3,5,7 and cylinder misfire on 7 bit there are no actual misfires except on 7 about once a day when the engine is cold. Sometimes I can go weeks with no misfires on 7. What could be causing this?
  • I recently liked one of your posts in hopes that maybe you can help me with this exact problem ... I have been to dealership 3 times and spent thousands and can show receipts to prove this and they are still unable to fix problem .... Long story short I am waiting for an entire EBCMwiring harness and it's about to get even more costly I am wondering if there is anything gm-chev do for there customers in situations like this ?
  • Old convo here I know.  But.    My father in laws 05 sierra recently had an electrical fire.   They got paid by insurance for the damage. And now  I own the truck....  so. It started like this. I just put all new brake lines on it.  Sent it back home to my mom... she calls and says the battery light came on and none of the gages are working. She shut it off and restarted it and all was well.   So I came up and hooked up my scan tool. Alt was putting out 15+. So identifix said if Alt is overcharging unplug the connector on alt if drops to 13 replace alt.    So I did.  All was well. Day after she said all the gages were going crazy. Then the next call was. Ring ring the truck burnt up. Fire fighters are pitting out the fire right now..... HUH? THOUGHT SHE WAS LIEING. But nope.   So I gutted the truck. And it looked like most of the fire damage was i n the dashboard above the dash support by the gas pedal. About behind the radio. . Bose wire harness had the most damage. While the main body harness in the dash had damage but it looked like that damage was caused by hot glass and melted plastic falling on it. And the roof harness and rear defrost was toast. There is NO rear defrost left in the rear window. I'm rebuilding this truck. But would LOVE I'm put on what gm screw up would cause this kind of fire I would post pictures but don't know how. There was only one blown fuse. For the 4x4. Right now I fixed the body harness. So it runs. No dash or anything installed only harness bcm andcsteeri MG colum.  No on star or xm. That's part of the bose harness.    
  • king80 said:
    My 2001 GMC light is on code reader at Auto Zone says misfire on coil1,3,5,7 and cylinder misfire on 7 bit there are no actual misfires except on 7 about once a day when the engine is cold. Sometimes I can go weeks with no misfires on 7. What could be causing this?
    Just had to clean out a fuel rail in a 6.0 06 sierra cause of missfire on 7     water gets in fuel and for some reason collects that side of the fuel rail. Rust also.   Pull out the whole fuel rail take all injectors out look in the top of each injector to make sure there isn't a lot of buildup in the screens .   Get new injector o rings andvreinstall.     And also gm used crappie valve springs and itc common to get a broken spring. 
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