Howdy, Stranger!

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

Chevrolet Impala Lighting/Electrical Problems



  • rstraubrstraub Posts: 6
    Guess what everybody who needs to get your BCM replaced! Go to NAPA, they have the BCM for just under $100.00. You'll still have to go to the dealer to get it "flashed" programmed. You can get a used one from your salvage yard but every dealer I spoke with said the same thing, "it may work for 20 - 40 key cycles then you're back where you started". That was enough for me to go to NAPA and spend the $30.00 more for their new one. Good luck, Rich
  • nosirrahgnosirrahg Little Rock, ARPosts: 872
    How much does the dealer charge to "flash" program it? And being totally ignorant on the subject, do you just hand it to them, they program it, and you install it later? Or does it have to be installed in the car for the programming to happen?
  • silverbugsilverbug Posts: 3
    Hello all. I have a 2001 Impala LS and recently, while I'm driving down the road, the headlights will flash (just the headlights, not the parking lights or high-beams), the AC compressor cuts off, and the battery light will come on, all at the same time. Then the car acts right for a few seconds and does it all over again. Even after I cut the car off, the headlights will still flash for about 10 - 15 minutes. It starts doing this early in the morning and gets progressively worse the hotter it is outside. All of the symptoms go away when the temperature outside starts dropping. Even with the BCM unplugged and the ignition in the On position, I have the same problem... any suggestions?
  • I called around to several different dealers and got anything from $150 to $95 (which is what I ended up going with). I drove to the dealership with the old BCM still in, told the tech I had the new one and would pop it in (it is pretty simple to get in and out if you are careful) and the tech just said "I will do it" and off he went. Took about an hour. It does have to be installed in the car for programming to happen. The dealer I ended up at didn't hassle me alot and was happy to get the $95 since the tech didn't have to be watching the thing the whole time and could work on something else while the BCM was programming. Good luck
  • I had this flashing thing happen a couple of times. I just finally had one of my friends disconnect the battery for about 15 minutes and then everything seemed to reset itself. I had tried going to the dealership a few times and of course they couldn't make the car do the same I've just decided that my car is haunted.
  • 0patience0patience Oregon CoastPosts: 1,638
    Man, I read these posts and just shake my head.
    Most of these BCM replacements are done needlessly and that is a shame. There is a known problem for the BCM connectors being loose and causing most of the problems described.

    If it is determined that it is indeed the BCM that is the problem, then you need to make certain that the updated BCM is installed.

    The BCM (Body Control Module) feed all of the body information to the PCM (Powertrian control module), which is essentially the main computer. If the BCM is unable to communicate properly with the PCM, then you have the problems.

    Bulletin No.: 04-08-47-003
    Date: August 31, 2004
    Security Light On, Engine Will Not Crank, Diagnostic Trouble Codes B2958 and/or B2960 (Repair Poor Terminal Connections at Body Control Module)

    2000-2005 Chevrolet Impala, Monte Carlo

    Some customers may comment on an engine that will not crank. Others may comment on the security light being on.
    Technicians may find DTCs (diagnostic trouble codes) B2958 and/or B2960.
    These conditions may have several different causes. In each case, however, testing of the BCMs (Body Control Modules) replaced for these conditions are frequently found to be operating to specifications and are believed to have been replaced needlessly. A change was made to the BCM hardware in February of 2003. An updated BCM can be identified by a GMAN169 or higher number found on the BCM part label. This hardware change was made to prevent the remote possibility that a BCM, built after the GMAN169 number, could be the cause of these conditions.
    The following are the likely causes of these conditions:
    1. Damaged or loose/unseated terminals in these BCM connectors may cause a security light or no start condition:
    ^ BCM connector C1 (24-way, pink in color), terminal B9 (white wire, circuit 1459)
    ^ BCM connector C1 (24-way, pink in color), terminal B12 (black wire, circuit 1835)
    ^ BCM connector C2 (24-way, grey in color), terminal A3 (yellow wire, circuit 1836)
    Important: Use only approved tools for removal and testing of terminals. Do not use unapproved tools to probe a terminal as this could cause damage. Use Probe Tool J 35616-6, from the J 35616-B terminal test kit, to test the terminals in the BCM connector.
    2. Check all the terminals in both BCM connectors, focusing on the three terminals listed above, for damage and proper seating of the terminal in the connector. If no damage is noted, follow the normal SI diagnostic procedures including clearing codes and attempting to duplicate the concern.
    3. Always check for and clear all DTCs after recharging or disconnecting the battery. Attempt to restart the vehicle only after all DTCs have been cleared. This will help prevent an unnecessary BCM replacement due to false DTCs being set while servicing the battery.
    4. A BCM should not be replaced when DTCs U1016 and/or U1064 have been set, even though the BCM is turning on the security light. Diagnose and repair or replace components as directed by the diagnostic procedures for these diagnostic trouble codes.
    5. A current or history diagnostic trouble code B2958 in the BCM and a loss of battery voltage due to a battery going dead or a battery disconnect may cause a no start condition upon recharging or reconnecting the battery. Clearing the diagnostic trouble code will allow the vehicle to start.
    6. The security light may turn on when the IPC (Instrument Panel Cluster) or PCM (Powertrain Control Module) does not receive a state of health message from the BCM within a specified window of time. DTCs U1016 or U1064 may set. Upon receiving the state of health message again, the security light will go out and diagnostic trouble codes will go to history. If this happens frequently, the vehicle may exhibit an intermittent or random flash of the security light.
  • slvimpalaslvimpala Posts: 14
    hey I'm an Owner of an 2002 Impala Base with the Crappy 3400 v6 and i noticed un like my other impala my 2004 Impala SS
    that my fuel Gauge Acts Up Very Bad and gets me Pissed off is no matter how much gas i have in there i can put 3 gallson of gas in there Give or take thats about quater Tank well time when i put in half tank and i go home or to the store and let the car sit the fuel gauge will show the low fuel light and it will stay right around the last line b4 the E line and it will not move up or down but yet when i gas it up it will show how much gas i put in like if i have 3 Gals in there now and i put in 3 more it will Regsiter 3/4 or it will be right on the full line and then it will just go down to the e mark after 12 miles of travel and gas light will come on and i dont have any leaks or anything Gm has just laughed and said Nothing we can do i told them if i crash this car into your Main Office you whouldnt laugh or if i sue gm for all the times this car has let me down and Ect ect
  • thekrautthekraut Posts: 7
    I started looking for info on 2003 Impala security/no start problem. Was directed to a Grand Prix discussion that had lots of these problems. One fix mentioned was cutting a wire in the Passlock harness and putting in a switch. Does this fix work on an Impala? Thanks for any help anybody can furnish!
  • 0patience0patience Oregon CoastPosts: 1,638
    One fix mentioned was cutting a wire in the Passlock harness and putting in a switch.
    Since the passlock uses resistance to activate it, I am not sure how cutting and putting a switch in will solve the problem. But, if you want to take a chance on your electrical system, then it's your vehicle.

    Personally, It's a whole lot better to fix the problem.
    My 02 Impala, I had to repair the BCM connector to fix the problem.
    Good luck with your problem.
  • okiejohnokiejohn Posts: 2
    Can anyone give me a reference or instructions on how to remove the light switch in a ’01 Impala LS? The dash lights don’t come on and I thought I would make sure the switch is bad before going any further but I don’t know the correct way to get it out.
  • I appreciate your concern! I actually removed the BCM from the black case it was in under my dash after all this started happening. There is a spot on the BCM where the solder is black and one of the resisters is loose. It looks like the resister burned up (maybe from the excessive Texas heat or from some surge) so I just went ahead and ordered a replacement BCM from the gmpartsdirect website ($300 cheaper than what it would've cost at the dealer). Reguardless, I still have to have it programed by the dealer when it gets here, which was quoted at being about $75. Now if that doesn't fix my AC/Blinking headlights/traction control problems, then I will be pretty upset. I'm pretty confident that it will though because once my car starts acting up, and I reach down and mess with that blown resister (or whatever) everything starts working fine again. It should be here by Wednesday (August 8th) so we'll soon see!!
  • kdconodkdconod Posts: 53
    I have a 2000 LS...and one of my fog lights, the driver side, is out. I replaced the bulb and cleaned the socket but it won't come on. Passenger side is OK, all the fuses are OK.

    What could cause only one fog light to be out?
  • I have a 2002 Impala that about a year ago started exhibiting strange electrical behavior. It starts fine and runs fine but all the electrical gauges including the speedometer "bounce". They all seem to bounce in time to a blinking light like the seatbelt light. The only way we can tell how fast we're going or how much gas we have is to see approximately the highest point of the bounce. Not the best of situations for a college kid's car. Has anybody else had this problem? Could it be the BCM I have been reading about? :confuse:
  • Shelley, does your speedometer "Bounce" only when a light is blinking? Like the blinkers, hazards, etc... or does it do that all the time. I am by no means a car expert but I really don't think it would be the BCM. Most gauges in cars are controlled by a vacuum of air (not sure about that in Imapala's though) same with the Air Conditioning controls. If I were to take a stab at your situation, it sounds more like the battery or maybe the alternator is starting to fail, and when a light blinks, more amps are being pulled from the battery which causes anything with any type of electrical relation, including the engine, to "drag". You can go to most auto parts stores these days and have both the battery and alternator checked for free, before spending an extravagant amount of money at a dealer or other shop. I would recommend that first.
  • nosirrahgnosirrahg Little Rock, ARPosts: 872
    The last time the battery went out in my 2000 Impala I noticed strange electrical stuff going on; mainly associated with the radio...things like pushing a steering wheel button to change the station, and it would go into seek mode but never lock in on a station and such. I couldn't figure it out and thought the radio was going bad, and then within a week or so the battery went dead. I replaced it and everything was back to normal. Could very well be the same problem in this case, but presenting itself in a slightly different way.
  • smucksmuck Posts: 1
    I have a 01 Impala and about a month ago my check engine light,hi beam out message,faulty fuel gauge,and my a/c compressor would turn on then off repeatedly.My transmission would shift hard at times.Took it to the dealer on tuesday the 7th of August and they said my valve body and PCS in the tranny needed rebuilding and my fuel level sensor needed changing.At first they couldn't figure out why the "hi beam out mesage" or the a/c problem.I must back up.While driving down the road the check engine light would come then go off as fast as it came on.Then day or night, brights or dims the "hi beam out" message would come on and also go out fast.The dealer wasn't really concerned about the a/c or the hi beam problem just the tranny problem.They said they never had one that flash that code.So I said there is a ton of Impalas on the road and there has to be someone else that had that error code.So I told them that they weren't touching the tranny until they could explain the "hi beam out" message and the a/c problem. Well it took 2 days but they finally changed the BCM.Any similar problems?My main concern is the tranny.They say its mechanical but I feel its electrical
  • nelsonrnelsonr Posts: 9
    I have an 04 impala base. about 4 months ago the security light would come on sometimes, I would turn off the engine and turned it back on and it would dissapear. but lately
    its been coming on at least 3 times a week. everything seems to be working fine under the hood. a couple of days while I was driving and putting my right signal light I heard the chime sound going off for at least 30 second. like when you open the doors with the key at the ignition.
    now that I recall it happened one time before long time ago
    but never pay any real atention to it.
    does anybody know what could it be ????
    any advise, coments ???????????????????
    thanks. :)
  • nelsonrnelsonr Posts: 9
    read mssg # 190 jul/29
    I had copied part of the mssg # 190 wich I think it would answer many questions, or at least give you more info about
    the BCM. now my next question ?? how can I have the BCM reset and tested, uploaded ,programed, before I replace it
    anyone ????????????try to avoid dealerships they're to expensive and they'd rather replace it. (I called)

    The BCM (Body Control Module) feed all of the body information to the PCM (Powertrian control module), which is essentially the main computer. If the BCM is unable to communicate properly with the PCM, then you have the problems.

    The security light may turn on when the IPC (Instrument Panel Cluster) or PCM (Powertrain Control Module) does not receive a state of health message from the BCM within a specified window of time. DTCs U1016 or U1064 may set. Upon receiving the state of health message again, the security light will go out and diagnostic trouble codes will go to history. If this happens frequently, the vehicle may exhibit an intermittent or random flash of the security light.
  • nosirrahgnosirrahg Little Rock, ARPosts: 872
    I think I read somewhere that the Impala will chime if you leave your turn signal on for an extended period of time. Not sure that was the situation in your case, but that's about the only logical answer I could think of.
  • No, it happens continuously. The turn indicators and etc. work fine, but the dash gauges all seem to have a heartbeat (Heartbeat of America? :{ ) Anyway, I am trying to diagnose a complicated situation with little or no knowledge. Thanks for your suggestions and any other help you can offer.
  • nelsonrnelsonr Posts: 9
    my wife works in a dealerhsip (chrysler) about the light coming on she asked one of the mechanics and he said the
    damn hated light might come on if the ignition key shows
    signs of excessive use (worn out)***this is only one of 1,000000 reasons **********************because the computer
    isn't getting a full reading of the key, and it can also
    kinda delay your ignition when starting up the car.
    he said to replace the key. I called the dealer it would
    cost me about $ 12 bucks.isn't too bad. im trying this first
  • How did this problem work out for you. We are having the same exact problem.

  • nelsonrnelsonr Posts: 9
    we have not done anything yet. the light hasn't come on since the last time I wrote about the problem. (6,days)
    but I am damn sure it will come on tomorrow just because im
    writing about it. I dont know anymore. I haven't had the chance to go get the key made, but I will some day.
    does anyone know about this problem ?????
    lowes got the key for $$4.80
    home depot for $$ 4.00
    wal-mart $$ 3.50
    dealer $$ 12.00
  • To all,
    I have recently had the same/similar problem. I now no longer have any instrument cluster light. The turn signal, cruise, idiot lights all work and so does the gear indicator (but it is extremely dim). I have checked the fuses and they all seem to be OK. I have no idea if it could be the BCM or not as it's only the illuminating lights in the dash that have been effected. Please help.
  • I have the same no start problem with my 02 impala since last May. Have been to dealer three times and they just can't duplicate it. I decide to take a look myself. Just wondering if anyone could point me to a step-by-step instructions on how to locate BCM and repair BCM connectors.

    Many thanks.
  • Hi, 0patience,

    I have the same security light/no start problem on my 02 impala.

    I tried to remove BCM from under dash but did not succeed. I can see a black box with 3 connectors ( I suspect it is BCM ). But somehow it seems hard to get it out since there is very limited space around. I tried to remove connectors first but did not find the right clip to disengage them.

    Just wondering if you could give me some glue on how to disengage the connectors and get the BCM out.

    Many thanks.
  • My IPC lights went out about a week ago. Did you get your's fixed. If so how did you repair? Thanks
  • I am having the same problem - Did you get yours fixed? Thanks
  • I have experienced no start/security problem for my 02 impala since last year. Decided to take a look by myself. Finally I managed to take the BCM off. I noticed a lot of yellow dots on solder points on the BCM board (both in front and back). Please take a look at

    Is it possible that the BCM is defective? Your inputs are greatly appreciated.
Sign In or Register to comment.