Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Chevy Silverado and GMC Sierra Electrical and Computer Questions



  • 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
  • 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 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 Posts: 8,054
    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.
  • 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!!
    Joe in Jersey
  • 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?
  • yosh1995yosh1995 Posts: 2
    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 Posts: 4,251
    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
  • 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 Posts: 8,054
    You need to disable Onstar. Not sure how you go about it. Perhaps a search on the web might turn something up.
  • 340mopar340mopar Posts: 1
    I came across your article on Edmunds and am curious about your fuel regulator. When running my AC in my 98 Silverado, NOT ALWAYS, the engine will begin to surge and act like it is running out of fuel. The engine then dies, and will not restart until the engine cools completely down, then it is ok, until the next time, Was this what your vehicle was doing? Would appreciate any help.

  • Hi oregonmarine. My 2001 GMC Sierra is having similar problems. My Automatic transmission will not shift unless you do it manually and I have no power to the tach, speedometer and my transmission indicator on the dash (PRND321) will not lite up. The gas gauge and the temp gauge also does not work. Then the next day, everything works perfectly. Then it goes back to not working again. Then back to working perfectly. Did you ever find out what is causing these issues? Please, Can anyone help?
  • pat110pat110 Posts: 1
    edited April 2010
    I purchased this truck over a year ago and have had significant problems with GMC's PASSCODE system, but have seemed to work those issues out. Now the when you shut down the truck and return to start it cold, no electrical power -no lights, no gauges, no interior lights, nothing. Here's the interesting part, if you hook-up jumper cables, (no need to jump the vehicle or even involve another car), the whole electrical systems springs back to life and the truck starts normally and runs fine only to have to do it again to start it next time. I've read a number of the previous posts, but I know my battery is good (tested, new), there is no abnormal power draw from the starter, my repair manual is hinting to the ignition switch, but am asking for any advice. Thanks
  • denhamdenham Posts: 76
    Have you checked your battery cable ends? From what I read this may well be your problem were the wires go in the cable end.
  • chevyk9chevyk9 Posts: 3
    I have a 09 chevy silverado. the cluster lights on the insturment panel stay on all the time while the truck is running. is this normal or something that i need to look into getting fixed? i thought the lights are suppose to be on only when the truck lights or on at night but they are on all the time. can some help???
  • paul707paul707 Posts: 1
    can anyone please tell me how to replace this thing!
  • gmcustsvcgmcustsvc Posts: 4,251
    I am from GM Customer Service. If you have automatic lights the instrument cluster will stay on. If you turn the lights off the instrument cluster lights will go off. Thank you,
    Mariah GM Customer Service
  • yosh1995yosh1995 Posts: 2
    UPDATE: For anyone that is having the issue described above with the turn signals and cruise control here is an update on my 2006 2500HD. I took it to the dealer and they fixed the issue by replacing the "multi-function switch on the column"....they replaced the turn signal switch. Costs was $348.00 for the diagnosis, parts, and labor to fix it. Not too bad. Sometimes its better to just take it to the dealer rather than wasting hours and and money replacing the wrong parts to track down an electrical issue!
  • akjbmwakjbmw Posts: 231
    In addition to what "gmcustsvc" said about the automatic lights staying on, you may notice that the dash lights will change brightness dependant on the light sensor at the center forward area of the dash. Mine works fine as long as I don't cover the sensor and cause a low light condition that makes the dash lights stay bright.
  • chevyk9chevyk9 Posts: 3
    In response to GM cusserv. I have turned off the lights to the vehicle and the cluster instrument lights still stay on. The sensor at the center area of the dash is never covered. This is driving me crazy.
  • gmcustsvcgmcustsvc Posts: 4,251
    Hello ChevyK9,
    I am going to research the lights to see if the vehicle is operating as designed. I will get back with you shortly to let you know what I have found. Thank you,
    Mariah GM Customer Service
  • steve302steve302 Posts: 1
    truck runs and starts great. runs good for 1st 20 mins of day. then radio goes off and on, wipers are slow and turn signals interfere with radio also engine hesitates and stalls. all things seem to be related. no one can solve my problem and the stalling is getting worse. after it stalls it does start up but as soon as its in drive it may stall again, any ideas appreciated
  • chevyk9chevyk9 Posts: 3
    Okay. I will wait to see what you say. Thanks
  • mrmremrmre Posts: 1
    had a local shop change out the distributor cap, and double check the computer for timing issues. The only codes that show is an oxygen sensor and 2 codes for the EGR valve.

    Since replacing the distributor cap and fixing timing issues the truck runs smooth and accelerates fine; however, after some extended driving, especially driving over 40 up to 50mph, the truck will accelerate by itself.

    The acceleration and changing of gears are smooth. The engine does not lag or feel like it misses a beat. After some time this issue goes away, but upon placing the truck in park the RPMs will shoot to 3000.

    My shop has disconnected the EGR valve(for a trail run) and asked if I notice the acceleration issue come back. Well it has, but this time it goes away rather than staying.

    Any advice or insight is appreciated.
  • obyoneobyone Posts: 8,054
    Have your throttle position sensor and idle air controller checked out.
  • whatsup3whatsup3 Posts: 2
    I have a 2001 Silverado 1500 5.3 L. Instrument panel lights are going crazy. Some times all the guages work and somtimes none of them work. Checked all fuses nothing blown. Anybody have any ideas on what's going on with these guages? Any ideas would be appreciated. :mad:
  • obyoneobyone Posts: 8,054
    GM had a bunch of defective clusters and had a limited recall on them. I'd try and check with a dealer if yours was covered under it.
  • whatsup3whatsup3 Posts: 2
    Thanks obyone,I will check with a Gm dealer about a recall.
  • bigmick11bigmick11 Posts: 1
    Does anyone know where the lighting control module is on a 2003 GMC Sierra?
  • I had to replace the whole gaslines on our 2003, due to rot!!!! Please have yours checked, as you could be losing gas or even be flammable!!!!
Sign In or Register to comment.