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Chevy Silverado and GMC Sierra Electrical and Computer Questions

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  • chevytrucker44chevytrucker44 Member Posts: 1
    So Im kinda going crazy and hoping someone can help!!! A day ago my voltage on my display was acting up and the battery message was displayed. It went away so i thought it was not big deal. Later on it proceeded to do the same thing only this time the voltage did not come back up to 14...instead the battery completely drained and killed all the electrical.

    I have since replaced the alteranator and the battery thinking this would solve everything and it ofcourse did not. The battery message is still displayed. It doesnt constantly stay on...comes on for about 5-10 seconds and then goes away. I have had both the new battery and the alternator checked and the computer says that they are fine. Anyone have an idea of what is up with the message?
  • myrvhaulermyrvhauler Member Posts: 4
  • myrvhaulermyrvhauler Member Posts: 4
    have a 2003 2500HD with the Allison Transmission.

    While driving this morning, the truck seemed to stutter and wanted to stop running. The truck did continue to run, but the engine light immediately came on.

    I used a Actron CP9135 diagnostic tool and received the following codes:

    P0087 - Fuel Rail Pressure Too Low
    P0700 - Transmission Control System Failure

    Does this diagnostic system work for the duramax?
  • tl54889tl54889 Member Posts: 1
    This morning my wife left with our 2001 Silverado, she got about a mile down the road and all the dashlights started flashing, the headlights started to dim and she barely made it back home. Truck ran fine but no lights.
  • dswartzeldswartzel Member Posts: 1
    My truck is haunted! AC goes nuts, DS seat heater comes on and roasts me intermittently. Dash instruments intermittently work, DS AC intermittently blows hot air when PS blows cold. Please any suggestions? I think the problem is a ground going bad somewhere. Can anybody point me in the right direction? Thanks,
  • gerossiegerossie Member Posts: 3
    Hello,

    I have a 2003 GMC Sierra 1500. For Christmas my wife bought me a remote starter for my truck. It was a pretty simple installation after I deciphered the instructions. In summary, the remote starter module hooks up to a bypass module and the bypass module talks to the truck through the OBD2 port to make all the functions work. The only interface points to the vehicle are the brake switch, the OBD2 connector, and a harness that plugs into the tumbler the is turned by the key. So there isn't any wire hacking going on here. So I get it all hooked up and it's working great. Now it's time to neatly tuck everything away and put all the plastic trim back on. While doing this I realize the harness that plugs into the tumbler is going to get in the way of the bezel that goes around the ignition. Under the steering column is this sort of large metal plate that is held in place by 4 10mm nuts. It's obvious that if I remove the plate and tuck the harness under the steering column and replace the plate that everything will fit quite nicely under the dash.

    How wrong I was.....

    After replacing the plate the truck will no longer start. It cranks. The instrument cluster lights up. It catches but does not stay running. Power door locks, dome light, power windows, and probably other stuff also do not work. The power mirrors do work. I completely removed all the remote starter related components and plugged the original plug back into the tumbler but still all the same problems.

    Can anybody help me diagnose this? I checked all the fuses that seemed relevent to any of the failing systems. At this point I'm in over my head, and I have a dead truck. I have no idea what to do.

    Happy New Year and many thanks in advance for any replies.
  • obyoneobyone Member Posts: 7,841
    If everything was replugged correctly, most likely a short somewhere caused the problem. At this point you might try and disconnect the negative terminal of the battery for 15 minutes and see if that works. If it doesn't you may have to do a wire by wire trace looking for an exposed or shorted wire with a meter. Not something real pleasant to do.
  • I have a 2004 GMC Sierra 1500, extended cab Z71, 5.3 ltr, automatic. It has the heated leather memory seat option. When I went to use the heated seat, neither side will remain on. When I press the seat heater buttons, the lights come on for a fraction of a second and then go out. This started simultaneously on both sides. I also noticed that if I turn on seat heaters while moving seats forward and/or backward, the lights stay on while moving seats and for a second or two after I quit moving seats. I also noticed a click (sounds like a relay making/breaking) from the module under drivers seat when I press seat heater buttons. Prior to this problem, I OCCASIONALLY had a problem with seat memory trying to move the seats all the way forward when keys were inserted. This was only an occasional problem, so I ignored it (out of warranty anyway). Is is possible both are related and can the bottom line be the module under drivers seat? Also: can it be reprogrammed or must I replace it ( if so, what is the official name for it?)? Dealer wants $115 to "check for electrical problem".
  • obyoneobyone Member Posts: 7,841
    The factory manual has a procedure to troubleshoot your problem. At $115 the dealer is charging about an hours worth of labor which is fair for what you've described.

    FYI, what you're describing is called the memory seat control module.
  • paladin3paladin3 Member Posts: 3
    For some time I have had electrical issues:
    I think I have a ground/return issue.
    With lights off, turn signals cause dash gauges to fluctuate in time with the flasher.
    With headlights on, dash lights go out, all gauges to to "zero" & the regular & high beams are reversed, i.e. the indicator is on high beams when they are not.
    Also, I believe something is draining the battery. Connecting a multimeter at the battery reveals a .25A discharge with everything off. Only thing I can see requiring power is the radio clock & .25A (250mA) seems like more than it should be.

    Any thoughts?

    Thanks, John
  • gerossiegerossie Member Posts: 3
    Turns out, coincidental or perhaps not, the bypass module I had installed with my aftermarket radio must have died. I remembered that when I installed the radio the dome light went out when I unplugged the factory radio. On a hunch I reinstalled the factory radio and the truck started right up and is running like a champ.
  • gerossiegerossie Member Posts: 3
  • obyoneobyone Member Posts: 7,841
    Cool. Glad it worked out.
  • shannadshannad Member Posts: 1
    I have a 2003 GMC 1500 and I was driving down the road from work the other day and it just died. All the dash lights, windows, door locks and lighs work but the truck wont turn over. The battery and alternator tests fine. Do you have any ideas.
  • obyoneobyone Member Posts: 7,841
    Bad ground.
  • bigblue7819bigblue7819 Member Posts: 2
    On new vehicles batteries sit on a shelf of up to 2 years before they get put in to the vehicles and people think that they bought a new truck or car it should have a new battery but new vehicles have a battery that is 1 to 2 years old.
  • bigblue7819bigblue7819 Member Posts: 2
    I have a 2005 silverado and the electric fans where kicking on in the middle of the night and killing the battery. i jump started it and then it started missing. i had it towed to the dealer and payed $95.00 to diagnose the problem they told me that it would stop missing if i turned off the A/C but i did that and it was still missing. they told me that i needed to replace the computer and that it would be almost $1,000.00 and 400 of that was labor. i had it towed back to the house and pulled the computer and found water in the harness. i cleaned up the connections and the fans have not come on any more and the truck ran great for about 2 weeks. then i was on my way back home and the truck just died. i took it back to the house and pulled the computer agen and found some more water in the harness. i cleaned up the harness and put electrical grease in the harness and used RTV to keep the water out. the truck runs fine now but the gauges and light in the dash start looking like a christmas tree. wile that was happening i turned off the truck and the doors did not unlock and the windows would not work. the dinger that tells you that your key is in the ignition would not go off when the truck was running.
    I am wondering if i should change the computer?
    I also wonder if the harness is bad?
  • gxr11gxr11 Member Posts: 1
    im having the same issue with my 91 c1500.

    intermitantly, when ever my parking lights are on, the gause cluster doesnt light up and all the gauges drop to zero, but at some point the temp gauge starts to slowly climb untill its pegged, i used to be able to get away with just giving the top of the dash a good pounding... now i need to buy a new dash...lol either way, let me know if you come up with a solution.... and i'll do the same
  • paladin3paladin3 Member Posts: 3
    Ok, so it has been diagnosed as the instrument cluster? That was posed to me as one possibility. Is that one whole assembly or is individual gauges? I guess if they are individual gauges maybe it is possible to disconnect one at a time......

    Thanks!!
  • gagjamgagjam Member Posts: 1
    I have a 2003 Chevy Silverado and was having a remote starter and an after market CD player put in.The truck will start up and run for about 1 to 2 seconds.The guy that worked on the truck pulled everything back out so he doesn't get blamed for it.The truck was towed to a repair facility and they worked on it for about 3 hrs.They looked at wire diagrams and traced all the wires they can't seem to figure it out.I forgot to mention that they put the factory radio back in and that doesn't work either.They have checked all the fuses and traced the wires with no luck,they even tried to hook up a computer up to the plug under the dash to try and diagnos the problem with no luck.The hand held computer is getting can't communicate with the vehicle.I am very frustrated and need some help trying to figure this one out so I don't get hosed by the repair facility.The guy that was putting in the remote starter and the radio is saying it has nothing to do with what he was doing and had the truck towed to a buddy of his who is singing the same tune.I have a hard time believing that esp when the truck was running fine until they touched it.Please help.
  • obyoneobyone Member Posts: 7,841
    The radio gets disabled via the theft programming. Looks like you are going to have to take this back to the dealer to reset the code on the anti-theft programming. Should you take it back to the dealer, you can ask them to disable the anti-theft.
  • goldenarchesgoldenarches Member Posts: 2
  • goldenarchesgoldenarches Member Posts: 2
    After turning my cruise control on, I tapped the button to increase the speed a little.

    The engine stuck wide open and will not idle down now. I took the fuse out for the cruise and the electronic throttle control, but it still will not idle down.

    Any idea would be appreciated.
  • 1998lincoln1998lincoln Member Posts: 108
    the engine temperature sensor! It was failing so it was telling the throttle positioning sensor that the motor was cold so it kept dumping allot if fuel. So when the gas was pushed it flooded it and it would die!

    Chevy Silverado's are having a problem with this !

    the low idle was a common problem on these engines. Actually, the real problem is that the accelerator is sticking (although this is not as evident as the low idle; this is why you feel the surge, instead of a smooth acceleration. The low idle is a by-product of this problem). The problem is due to hydrocarbon (sludge) buildup inside the throttle body, and possibly the air flow sensor.
  • 1998lincoln1998lincoln Member Posts: 108
    I know someone else that is having the same problem you are going through !
    It had something to do with his Key to the ignition ! It is programed to start the truck
    but it was acting up, and the truck would not start. He went to the dealer and they had to get him another key, just any key will not work !

    Hope this helps you ! Good Luck !
  • 1998lincoln1998lincoln Member Posts: 108
    Try installing a ground wire from the fire wall to the engine block !
    If this is not grounded good it will cause the dash gauges to act up !
  • bob2003bob2003 Member Posts: 1
    My 2003 Silverado electrical system is completely dead today. I noticed while driving yesterday all the gages went to zero and all alarm indicators came on for a few seconds then went back to normal. First time I ever saw this. Now today , no lights , nothing , everything dead. Battery is fully charged.
  • 1998lincoln1998lincoln Member Posts: 108
    I know the Silverado has this problem alot. One owner pulled the computer and found water in the computer and wiring harness, he cleaned the computer and the harness, and put some type kind of grease on the computer and harness to seal it up so water will not get back in to the system. Also, make sure you have a good ground wire from the fire wall to the engine block! This has always been a problem on any make, if this ground is bad it will cause these kinds of problems !
    Good Luck !
  • paladin3paladin3 Member Posts: 3
    Replaced Dash cluster. Everything appears fixed

    JDH
  • opc167opc167 Member Posts: 14
    I bought an 03 1500 6.0l. Is there an aftermarket computer you would suggest that setting may be applied to help gas mileage? I was expecting better than 13.2.

    thanks
  • 1998lincoln1998lincoln Member Posts: 108
    Surge Performance Chip
    Manufacturer: Surge Engineering

    http://www.yourhotcar.com/product/list/2003/Chevy/Silverado/Ignition_Systems/

    Maybe you would prefer to beef up your old computer !
    This chip is for Chevy Silverado ! Copy and Paste the web address above and check it out !
  • steels34steels34 Member Posts: 1
    edited February 2010
    What happened? Battery went dead needed a jump, after the jump i lost power and now the transmission will not seem to engage forward or reverse. help please
  • dave282dave282 Member Posts: 1
    Mine did that too. The instrument panel cluster is defective, but GMC has a 7/70 warranty on the panel. I took mine in and they completely replaced the IP.

    But your warranty is only good to 70,000 miles or 7years ownership. Plus they never sent anyone a notice about the defect. Hope this helps.
  • 1998lincoln1998lincoln Member Posts: 108
    your transmission has electric solenoids, that need power to work,also your computer could have some how been damaged when you where jumped !
    Also, check your fuse for the O2 sensor, your trans is on the same fuse !
    Replace it and then try out your transmission again !
  • denhamdenham Member Posts: 76
    A weak or bad battery will kill power as the needed voltage is not there as it is lost going into the battery.
  • tnt6ft7tnt6ft7 Member Posts: 1
    i cant get my dome light to come on when i turn the key off and open the door, i have checked the fuse in the side of the dash and it is good, the bulbs are good you can actually turn the lights on with the knobs and the lights them self but not when you open the doors or turn the key off. this is on my 07 gmc 3500hd
  • barry_wbarry_w Member Posts: 1
    Hi All
    Just purchased a Sierra 2500HD Classic with the Duramax diesel. The hand book refers to a number of settings that can be changed via the DIC. I do not have the buttons on the steering wheel to access these functions, does anyone know whether the same module is used in all trucks, and is there a way to add external control buttons to access the info?

    Barry
  • usmcothusmcoth Member Posts: 1
    ELECTRICAL FIRE HAZARD THAT AFFECTS THE HEATER, AIR CONDITIONER, CRUISE CONTROL, ABS, AND BRAKE SYSTEMS ON 2005 CHEVROLET SILVERADO MODEL TRUCKS. A SHORT IN THE ELECTRICAL SYSTEM IS COMMON ON THESE VEHICLES AND KNOW BY THE DEALERSHIPS TO EFFECT MULTIPLE POINTS AS A DIRECT RESULT OF A SHORT IN THE ELECTRICAL SYSTEM WHICH COULD LEAD TO AN ELECTRICAL FIRE OR SERIOUS INJURY FROM SYSTEM FAILURES. ITEMS THAT ARE AFFECTED INCLUDE BUT ARE NOT LIMITED TO FUSE BOX, WIRE HARNESS, WIRE CONNECTORS, THE HEATER/AC BLOWER MOTOR, FUSES, RELAYS, AND MANY OTHER PARTS. THE SYSTEM SHORT THAT OCCURRED IN THIS VEHICLE WAS IDENTIFIED BY THE DEALERSHIP WITHOUT EVEN SEEING THE BURNED PARTS.
  • barnowl3barnowl3 Member Posts: 70
    Do you have more info, such as TSB or recall info? I have 2003 Sierra. It had the charging system wiring replaced under warranty due to some kind of short (was a TSB) which wiped out the alternator. I seem to smell slight electrical burning smell occasionally in the cab. Luckily, insurance is current :)
  • scott_62scott_62 Member Posts: 1
    have you found a solution to this problem yet? I have an 02 silverado 2500hd with a diesel that is having the same problem.
  • traveler6962traveler6962 Member Posts: 1
    i went out this morning to start my 08 2500hd chevy put the key in the ignition turned the key only to see this icon ,which is, a little picture of a truck n a lock on it /in otherwords the security icon which is prohibiting my truck from starting. all gauges are fine have new oil n fuel filter but turn the key n nothing . anybody else have this problem
  • oregonmarineoregonmarine Member Posts: 1
    Hi, I have a 2003 Chevy Silverado 1500 4x4 with a 5.3 and 135,000 miles. I was driving home today and had the cruise control set out on the highway. The "ABS" and "Check Braking system" lights came on, and at the same time my speedometer dropped to zero and kept jumping up to random speeds then falling back down to zero in the same manor as a blinking dome light due to a door ajar. Like it wanted to work but couldn't maintain connection. I pulled in to a rest stop and was able to slow down and stop without a problem. Brakes felt normal and at that point I thought that my problems could be solely electrical. It wasn't until I tried getting back on the road that I realized my transmission wasn't working right either. I could hear the engine rpm's going up with a bit of a whine but the darn thing wouldn't shift. Then it decided to work, Then it stopped shifting again. Didn't hear any grinding or clunks or anything and I was able to manually select gears but it's as if my tranny just didnt know when to shift but at times everything worked like normal. For the last 20 miles it was hit and miss. SO everything combined I'm scratching my head thinking maybe its electrical?? My knowledge, and funds are very limited. I'm a disabled vet on a very fixed income and I'm starting school in ten days.. I don't have the time or the money to get jerked around by a mechanic. If it was a 1963 model my dad would know how to fix it, but he's just as lost as I am and he's my go to guy when it comes to stuff like this. Does anyone have any advice? I poked around under the hood. Checked fuses, checked my tranny fluid. Everything seems fine. Fuses were all good and the tranny fluid was good and red and didn't smell burnt or anything. My tranny and braking system has been working great up till today. Havent had any problems with either and I had everything checked at 100,000 and again at around 120,000 before my extended warranty expired. Any advice anyone could offer wold be greatly appreciated and I'm sorry for adding any unnecessary details. Just hoping something mite ring a bell to someone and hopefully someone can help me. Thanks for reading.
  • jlp09jlp09 Member Posts: 1
    edited March 2010
    My 2001 Chevy Silverado 1500, 5.3 vortec, is misfiring on multiple cylinders while idling in drive. When I stop at a red light, some times, the misfiring is so bad that it noticeably shakes the whole truck like I'm in the middle of an earthquake. The hotter the engine temp, the worse it is. I bought a Diablo Sport Predator programmer/tuner/diagnostic tool to help find out what the problem is. The Predator has the capability of live data feed,a.k.a.- real time data. I plugged the Predator in and it says that everything runs good while driving, but when I come to a stop, idling in drive, like at a red light or stop sign, the Predator says my engine is misfiring on multiple cylinders, but as soon as I get rolling again, its fine. Also, when I give it gas to get rolling from a stop, it does the weird jumping/ hesitating/ stalling thing( I honestly don't know what to call it), but just for a second. The Check Engine light doesn't come on and the Predator shows NO trouble codes. I've replaced spark plugs and wires, throttle position sensor(TPS), BOTH knock sensors, cam sensor,and today I am going to put in a new fuel filter. Assuming the fuel filter isn't going to help, what is the problem? Please, someone help!!!
  • obyoneobyone Member Posts: 7,841
    When was the last time you cleaned/replaced your IAC (idle air controller)? Manufacturers recommend replacing as the chemical (throttle body cleaner) may damge the IAC.
  • jerseyjoe6jerseyjoe6 Member Posts: 2
    Hello All...
    New to this forum, and I'm looking for a wiring diagram for 2006 Sierra seats.
    I'm not sure what options are in these electric seats... I picked the seats up out of a wreck... put them in my Willys Jeepster, now would like to make them work.
    Any help and assistance would be greatly appreciated. (Printed pdf file would be superb!!
    Thanks,
    Joe in Jersey
  • gmsteve85gmsteve85 Member Posts: 1
    hey im having some issues with my truck, my starter is acting up. it has been replaced and still have trouble starting. some days it works no problem, then another day ill go to start it and it wont. i turn the key and it almost starts the stalls, then i turn it off and try again it starts rite up. people have been sayin its my ignition swtich is bad, also today my heat is control is acting up it will on turn on if i put the switch a 5 and then it comes on. any suggestions what is goin on with my truck?
    thanks
  • yosh1995yosh1995 Member Posts: 2
    Hi,
    I was wondering if you found what the problem was on your truck. My 2006 model is doing exactly the same thing, started a few days ago. Any help would be much appreciated.
  • gmcustsvcgmcustsvc Member Posts: 4,252
    Hello,
    I am from GM Customer Service. I would recommend taking your vehicle to a dealership, and at least having them diagnose the problem. That way you know what you are dealing with, and figure out how to proceed from there. Thank you,
    Mariah GM Customer Service
  • thorodinsonthorodinson Member Posts: 1
    With a 2009 Silverado 2500 4X4 HD everything from my mileage to tire pressure and percentage of engine oil still OK is monitored and sent to my email address. I can imagine that the location can be monitored and length of trip recorded. Too much big brother. Can this be shut down or bypassed. Does it take a replacement of the original computer with something that allow me to retain my privacy? The mileage odometer is electronic. Can't imagine that a simple battery change will wipe out that stored info--maybe there is another power source on the motherboard.

    I don't want or need the big brother approach. This replaced a 1973 Chev 2500 that had two engines replaced and I knew every nook and cranny. Now I have to let the computer run certain operations but want to keep the rest private. Ideas? Thor
  • obyoneobyone Member Posts: 7,841
    You need to disable Onstar. Not sure how you go about it. Perhaps a search on the web might turn something up.
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