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Chevy Silverado and GMC Sierra Electrical and Computer Questions

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Comments

  • canayjun64canayjun64 Member Posts: 34
    Thanks barnowl3... Humm I guess I'll have to see if a bulletin comes out indicating a contradiction to what they said. So far nothing out there for the 2009 models.

    Like you said, it helps to provide the info.

    Cheers!
  • rogerpwillisrogerpwillis Member Posts: 2
  • rogerpwillisrogerpwillis Member Posts: 2
    I have a 2003 Chevy 1500 with 148,300 miles (owned since new)....Has been a Great truck.....recently the message display will go from english to french to spanish...it will get stuck on hours used or trip...sometimes the trip will reset itself...it will let me set it on english and it will stay sometimes... Anybody got a clue???????????? Thanks Roger
  • barnowl3barnowl3 Member Posts: 70
    Sounds like you need to have the gauge cluster replaced. The erratic gauges and speedo issues are part of the bulletin and lawsuit. If you get there before 70,000 miles they'll cover it. Between 70 and 80,000 miles, you only get the parts for free and may need to send the info in to get the credit. The lawsuit covers you from 70,000 to 80,000 miles.

    I have also had the radio cut out normally on my '03. The first time the dealer put in some kind of software update. It has happened 1 or 2x since then and just seems to correct itself.

    The other problems may be related to your gauge cluster, get that fixed first and before it is not covered.
  • kb52kb52 Member Posts: 1
    The a/c, heater electronic display flashes on and off and I have no control of the temperature. The display unit has been replaced once, with the same symptoms. The condensor coil was replaced and the system re-charged when the problem started. I understand the display had to be removed in order to have access underneath the dash. Any ideas on to how to repair this would be greatly appreciated by both me and my mechanic!!
    Thanks, Kenneth
  • canayjun64canayjun64 Member Posts: 34
    kb52...I had a similar issue with my 94 Concorde. It turned out to be a cold solder on the display control. By banging the display slightly, I was able to re-gain control of the temperature temporarily. It was a bit tricky to find but with the help of a magnifying glass, I was able to locate the problem and fix it.

    Who knows...it might be just that. Good luck!
  • johnny_tjohnny_t Member Posts: 1
    I have a old but well kept silverado from -89 it is a 6.2 diesel, and everything is working just smoothly. the "service car soon" lamp is lit, and i would like to know what the warning lamps indicates. therefore i am looking for a owners manual on the internet, but seem to find only for newer models. anybody know where to find this? i actually bought the heyes manual, but cannot locate it there,
    Regards
    J
  • canayjun64canayjun64 Member Posts: 34
    johnny_t.... did you tray a Haynes manual? Thet are quite good. Try this link.

    http://www.haynes.com/products/year/1989/make/Chevrolet/model/Pick-Up/productID/- - 246

    I've been using them fo all of my vehicle I owned and they are very helpful.
  • bob2007chevybob2007chevy Member Posts: 1
    I have a new body style 2007 Silverado, quad cab. When I use my left blinker, my blinker and my back up light both blink. After a few moments, the blinker blinks very fast. I changed the bulbs. I have over the 35,000 miles on the truck.
    Any suggestions?
  • obyoneobyone Member Posts: 7,841
    Take it back to the dealer before your factory warranty is up.
  • seabeemaxseabeemax Member Posts: 5
    Have you changed any wires on the pig tail :sick:
  • whatnxtwhatnxt Member Posts: 3
    The alarm in my 2000 Sierra went off and I couldn't stop it no matter what I did. I used the remote and the key to no avail since this would only stop it for a few minutes to a few hours, then it would go off again and the only way to stop the noise was to disconnect the battery. I tried for a couple of weeks to figure it out myself but was not able to resolve anything. This was in mid June

    I finally took it to an alarm specialist and they checked the truck out from top to bottom and concluded that the problem was not with the aftermarket alarm the dealer had installed but with the factory alarm that came with the truck. I did not know they were separate but still functioned with the one remote. He showed me by changing the sound in the aftermarket alarm, then triggered the alarm in different ways to activate first one then the other. This was possible because the factory alarm doesn't have motion sensors, but is activated by the opening of the doors and such. By doing this I was able to distinguish the two alarms going off by their different sounds, with the factory alarm sounding the horn while the aftermarket sound was a siren. They did all this so that I could take the truck home and the next time the alarm went off I would know which one had gone off by the sound, i.e. the horn or siren. That night the alarm went off and just as he said, it was the factory alarm since the horn sounded and lights flashed. I disconnected the battery and next day called the alarm place. He said they would not be able to help me since they only worked on aftermarket alarms because the factory alarms are tied into the BCM which he thought needed to be reprogrammed in order to fix the problem. He said it was a computer problem not a physical problem (as in wiring) and for this I needed to take it to the dealer.

    The following week I took the truck to the dealer and explained everything that had occurred and the information from the alarm specialist. Dealer had never heard of this problem. He said they would look into it and call me when they had any information. Next day I got a call and was told that they needed it for one or two more days. Two days later I was called and told that all physical components were okay, and that the problem was with the BCM. BCM was replaced, I took the truck home, and unfortunately, the alarm just went off last night again. Will be contacting the dealer again.

    This is also an answer to post #30, #221, and #260. I will keep you informed as I find out additional information. If anybody can help, please answer. Thanks.
  • obyoneobyone Member Posts: 7,841
    I took the truck home, and unfortunately, the alarm just went off last night again.

    Which alarm?

    When did you install the aftermarket alarm?

    Which remote are you using?

    If I'm not mistaken, the aftermarket alarm also ties into the BCM.
  • whatnxtwhatnxt Member Posts: 3
    The factory alarm is the one that keeps going off, and the aftermarket alarm was installed when I bought the truck. I am the original owner. They are both intergrated into the remotes. The way I understand it, both are programmed to the remotes you get when you buy the truck but are still two separate alarms that can function as one. I was told by both people that worked on it that the main alarm will always be the factory one and that only the dealerships can work on them because of the programming issue, since it's tied into the BCM. Aftermarket companies do not and will not touch the BCM. This also means that if you ever need a new remote you have to get it from the dealer because it has to be programmed to that vehicle via the BCM. This leaves me and anyone else with this kind of problem at the mercy of the dealers. That is unless someone out there can help with new info. Thanks for the response.
  • obyoneobyone Member Posts: 7,841
    The dealer installed the aftermarket alarm when you originally bought the truck?

    Sounds like something is shorting to ground as in bad wiring.
  • ffkc120ffkc120 Member Posts: 1
    :sick: I have had many similar problems. I have a 2006 GMC sierra 1500 4x4.. and my brake lights will burn out almost every other month, along with the parking amber lights. Just the other day i was headed to work and pushed in the cigg. lighter and smoke started rolling out from under my dash. I had to pull over and let the smoke clear out. I could smell burnt rubber. then the next day, I stopped at the gas station and turned the truck off, and it wouldnt even turn off. then it said service 4x4 system, which had never been used. I drove home unhooked the battery to turn it off, still wouldnt turn off, then i unplugged fuses untill it would turn off. I took it to the dealership and talked to gmc customer service .. it now needs 1400$ worth of parts and new wiring harness. gmc tells me they cant assist in payment because there was no mechanical defect?? im not to sure how it was my fault at all, and how it wasnt a defect. hopefully this doesnt happen to your truck, i know i won;t buy another one.
  • grampa2grampa2 Member Posts: 5
    truck only goes 40 km/h- light on dash says engine power reduced-truck is in great shape-what could be the problem-never heard ot this type of waring light????
  • himiehimie Member Posts: 4
    I have a 2003 2500 Sierra with factory alarm thatbis going off in the middle of the nigh. I was wondering if you ever came up with a solution to your problem.
  • grampa2grampa2 Member Posts: 5
    disconnedted battery for a few minutes, it must have reset.try e-mail the alarm company and ask them, they usually try to help???
  • idaho3idaho3 Member Posts: 1
    Anyone know how to turn the tire pressure monitor off. I have changed wheels and tires. I do not what to unmount the original wheels to get the tire pressure senders
  • himiehimie Member Posts: 4
    I disconnected my battery for about 10 hrs. After reconnecting it my factory alarm went off like it did previous times in the middle of the nite. Took about 1 hr after being reconnected before it went off again. Anybody know who to contact about a factory alarm. GMC dealers want $100 to check it out. Trying to save some money if it is something simple.
  • 2004ssguy2004ssguy Member Posts: 2
    I have a 2004 SS and the left turn signal won't work sometimes. It won't light up any of the lights even the dash and is very sparatic. Won't ever do it when it's in the shop. I have already but in a new turn signal switch which changed nothing. Sometimes you can hear a really clicking really fast.
    Help
  • 2004ssguy2004ssguy Member Posts: 2
  • vhdvhd Member Posts: 2
    Does anyone know how to over ride the system so that the DVD player will play on the riding screen while the truck is in drive..
    Agin this is a very important question so i can watch football while my wife is driving!!

    Seirra Danali 2009
  • himiehimie Member Posts: 4
    I have a 2003 GMC SIERRA PU. Security Alarm will go off anytime. I have tried to disconnect the battery and for a period of time, but still sounds off anytime. Has anybody had this problem and how did you fix it?
  • shaneoshaneo Member Posts: 2
    I have a 2001 chevrolet silverado 1500 and my lights just like yours comes on and stays on I personally have a relative that works at the dealer ship and he too put my truck on a dianostic machine and it gave two codes.The machanic said it was a computer module that went bad so I read your story and I wanted to share it with you....maybe it could be the same problem. Write back to me at shane_denais@yahoo.com. Shane
  • embiarembiar Member Posts: 1
    I have the same problem, it is in your tilt steering column not the fuses or headlights, I have not broken it down yet to find the answer that is why I looked to here to see if anyone had similar problems, if you raise your tilt all the way up they should come on intermittently, I am not sure if it is a wire degraded from the strain of being bent back & forth or it has some type of contacts since the travel is extensive, but I have had to jar the steering column sometimes to get it to temporarily work, I hope this at least points you in the right direction, I will let you know if I find the permanent fix, is seems it is a common problem with that design & is used in numerous GM vehicles
  • levin1levin1 Member Posts: 8
    My 2001 Chevy 2500 HD 6.0 liter is misfiring on #'s 2,4,6,8 cylinders and if I understood it correctly it is all on the passenger side. It just happened over night. It came up on the computer as being one of three things. Intake gasket, bad plugs or wires. Had the gasket replaced and drove it home about 7 miles and it ran fine. Sat for two days started it up and it was misfiring again with the service engine light flashing as before. I do have a bad catalytic converter that has been rattling for about 4 months, I don't know if that has any bearing on the problem or not. Thanks for any help.
  • himiehimie Member Posts: 4
    While driving the truck last weekend my dash was reading "Right Door Ajar". My lights were also staying on. A couple times I couldn't get my inside lights to turn off after the alarm sounded until I disconnected my battery. So I took it into the dealership and told them what was going on. They said my switch in the right door was tested and said it was bad, It cost me $427 for parts and labor. It has been 5 days and the alarm has not sounded, and it was happening alot if I had the battery connected. Keeping my fingers crossed.
  • carnut69carnut69 Member Posts: 1
    2007 Siverado 1500HD battery dies when truck is not used for more than 3-4 days, I have had the dealer do many tests and no real answers, the battery has been changed out twice, the truck is optioned up pretty good, so there are a lot of draw functions on it, but the parasitic draws are not out of line according to the dealer, I would like to use a bigger better battery, but the space won't allow this....any one had this problem???, the truck is well maintained, and had about 21K on it
  • greywrenchgreywrench Member Posts: 2
    if the rattling cat is on the passenger side it may be your problem. if the cat is not burning off unburned fuel the post cat oxygen sensor will read a rich condition and the computer will deliver considerably less fuel to that bank of cylinders causing misfires.
  • levin1levin1 Member Posts: 8
    Thanks for your response. I haven't had any trouble with the misfiring for a week. The rattling at the cat area has stopped, actually right before the misfiring started. I did get a diagnostic check run on the truck after the intake gasket was replaced and it misfired again and nothing came up, cats are good at the current 77,000 miles. I thot for sure the cats were bad, something was rattling under there and I never could find out what it was, everything was tight. Its purring like a kitten now, I'll keep on trucking. Thanks again.
  • kodak1kodak1 Member Posts: 1
    just joined this forum hope this helps you it was my problem my battery would always run down on my 06 4x4 it ended up being my windshield wiper motor shorting against the body try unplugging it for a few days. later
  • denhamdenham Member Posts: 76
    Service Engine Light with Code 440 emission fault, can not seem to find the problem.
    Have checked the wires and plugs, gas cap,etc. The canister is ok, but not sure how to check the purge solenoid? Anyone who has had this problem or idea I can use!
    With the code cleared you can start and drive maybe three times before the service engine light comes back on.
  • shaneoshaneo Member Posts: 2
    here is your solution unplug the battery for 3mins just enough to reset your truck and pllug back the battery and turn your ignition back on a wham bye bye service engine light.....keep me posted
  • obyoneobyone Member Posts: 7,841
    P0440


    DESCRIPTION
    The EVAP LARGE LEAK TEST is based on applying vacuum to the EVAP system and monitoring the rate of vacuum decay. The Powertrain Control Module (PCM) uses the input from the Fuel Tank Pressure (FTP) sensor in order to determine the rate of vacuum decay. At an appropriate time, the PCM turns the EVAP canister purge valve ON (open) and the EVAP canister vent valve ON (closed). This allows the engine to draw a vacuum on the system. At a calibrated time or vacuum level, the PCM turns the purge valve OFF (closed), and tests the system vacuum. If the system is unable to achieve the calibrated vacuum level, the PCM will set DTC P0440.

    CONDITIONS FOR RUNNING THE DTC

    •DTCs P0107. P0108, P0110, P0112, P0113, P0115, P0117, P0118, P0121, P0122, P0123, P0125, P0443, P0449, P0452, P0453, P1106, P1107, P1111, P1112, P1114, P1115, P1121 or P1122 are not set.
    •The system voltage is between 10-18 volts .
    •The startup (ECT) engine coolant temperature is between than 4-30°C (39-86°F) , but the start up ECT is not more than 8°C (14°F) more than the startup IAT temperature.
    •The startup (IAT) intake air temperature is between than 4-30°C (39-86°F) , but the start up IAT is not more than 3°C (7°F) more than the startup ECT temperature.
    •The fuel tank level is between 15-85 percent .
    •The Barometric Pressure (BARO) is more than 75 kPa .
    •The Vehicle Speed Sensor (VSS) is less than 75 mph .
    CONDITIONS FOR SETTING THE DTC
    The EVAP system is not able to achieve or maintain vacuum during the diagnostic test.

    ACTION TAKEN WHEN THE DTC SETS

    •The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
    •The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.
    CONDITIONS FOR CLEARING THE MIL/DTC

    •The control module turns OFF the Malfunction Indicator Lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    •A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    •A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    •Use a scan tool in order to clear the MIL and the DTC.
    DIAGNOSTIC AIDS

    •Use the EVAP pressure/purge diagnostic station in order to pressurize the EVAP system to aid in locating intermittent leaks.
    •Move all EVAP components while testing with the Ultrasonic Leak Detector.
    •A temporary blockage in the EVAP canister purge valve, purge pipe or EVAP canister could cause an intermittent condition. To repair a blockage in the EVAP system refer to Evaporative Emission (EVAP) System Cleaning. See: Emission Control Systems\Evaporative Emissions System\Service and Repair
  • denhamdenham Member Posts: 76
    Yes undo the battery will clear the code and the light will go out, but not fix the problem. The gas tank must build up pressure and most often it is the gas cap weak from use and you get the check engine light. This was my problem and I would say that anyone who has check engine light what any type auto they should first replace the gas cap as it could very well be the problem at little cost.
    Dennis
  • ahuff12ahuff12 Member Posts: 3
    03 1500 silverado..left turn signal will stop blinking when i put foot on brake pedal
  • ray102ray102 Member Posts: 1
    my gadges go up and down and my batt. light comes on for a couple second and the gadges go crazy, rpm,speedomoder, oil,water temp, alt gadges go crazy and then quit working. does any body knows the problem please let me know. I change the alt. still not working. ray.
  • azjasazjas Member Posts: 6
    It is the ignition harness causing you all the problems.
    Replace it -
  • silveradoz71silveradoz71 Member Posts: 2
    We just bought a 2003 Silverado 1500 Z71, today we were leaving a store and all the lights on the instrument panel lit up (all of them at the same time) and the headlights dimmed for a second, then everthing was fine, went to another store and when I shut off the truck the electric door locks did not unlock, so I tried to start the truck and it was dead, nothing would come on, after a few attempts to start it, it just suddenly started, so we decided to go straight home, a few seconds after we pulled out the lights all came on again, Ive tried starting it a few times since with no problem, has anyone had a similar problem or any suggestions for me? i dont want to be left stranded somewhere.
  • silveradoz71silveradoz71 Member Posts: 2
  • tcbusatcbusa Member Posts: 4
    huff, I had this problem with my 99' silverado 4.8,i replaced the fuel press. regulater & solved the problem.Got the part @ napa 84$,hope this is it.do it yourself job. tcbusa
  • bambam25bambam25 Member Posts: 2
    I have a 2006 silverado with 2 codes 1 is p0102 mass airflow sensor low circuit frequency and p0449 vent solenoid control circuit how can i fix these 2 problems
  • bambam25bambam25 Member Posts: 2
  • mark2003z71mark2003z71 Member Posts: 1
    Short story long, I had to jump my truck in the dark and like a big idiot I crossed the cables on the battery for about 30 seconds. Noticed the black cable on the positive post glowing. Quckly switched them and the truck started ok and made it home. I know, very stupid. Since then I have been getting a rough idle at stop signs where it feels like it might stall and the battery gage begins jumping from about 11 to 16 or so and it normally sits right at 14. I am also getting behavior where the radio will change stations or jump to new cd tracks if I hit one of the seat location buttons in the drivers side door and back to the original when I hit the other. The seat changes position to the correct position like normal. I have also had the radio turn off and reset itself back to 12:00. I have checked all of the fuses that I could find in the dash and in the box by the battery and they all seem good. Any thoughts on what I might have fried and how I can fix this?
  • mcnasty333mcnasty333 Member Posts: 1
    my passenger side door is "dead". I cant roll up or lock that door and the remote lock is not working either. It also stalls out while driving once and a while. Checked all the fuses?????? any help is appreciated
  • seabeemaxseabeemax Member Posts: 5
    :sick: Hate to say but it sounds like your door is unplugged maybe on the inside.
    Your going to need to pull the door panel and check the connection.
    Good luck
  • stlcty79stlcty79 Member Posts: 1
    I have a 2003 GMC 1500 (5.3L V8) with 107,000 miles, which has been acting up recently. About a month ago, on a dark rainy night, I took the truck out to run some errands and noticed that while having the headlights, wipers, and windshield defroster on the truck seem to strain at Idle or when I came to a stop (strain= headlights would dim, the engine/electrical system would cycle, then return to normal). When I was driving no issues. After this happened a few times, I turned the defroster off and it strained again but no issues after that.

    The next day, early am (still dark) I had to ran into a similar situation, but the truck then stalled. I promptly replaced the alternator, thinking that it was faulty due to the mileage and age of the truck. Still had issues, many close stalls when I would come to a light but no stalls.

    After a few more issues, and some wondering if I would get stranded somewhere, I put a volt meter on the truck. Read 14V when it was idling, but when the headlights and defroster were turned on the volts dropped to 8 or 9. So, I figured it may be the battery and replaced that with a "red top" Optima battery.

    Even after all that, I am noticing some of the same issues with running the windshield defroster at night and the headlights. The truck strains, but does not stall and the volt meter will return to 14V on the dash after it cycles. I have noticed lately that this is also happening with the rear window defroster (even if it is on and the windshield defroster is off).

    Anyone have any ideas? I want to point the final finger at the heater motor/heating system but am not sure. Could this also be a relay issue? Anybody hear of this happening to others?

    Only other issues to date are, the instrument panel has a light burned out on the speedometer. The 4WD switches stopped working one day (months ago), but came back and are fully functional again. Last year I replaced all the plugs and wires as a DIY tune up and have had no issues with them. Truck came back to life when I did that..

    The truck runs like a champ all the other time. I still love my truck.
  • barnowl3barnowl3 Member Posts: 70
    I had problems with my charging system on my 2003 2500 when it was about 2.5 yrs old. Voltage took wild swings high and low. Dealer replaced wire harness to alternator 'for proper continuity' per bulletin /PI. 73170D. That did the trick. 2 months later though, they did need to replace the 'intermittent' alternator due to undercharging. I did need to replace the alternator again this year ( 7.5 yrs old, 55,000 miles).
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