Close

User Tag List

Results 1 to 12 of 12
  1. #1
    onefast84's Avatar
    Join Date
    May 2007
    Location
    United States
    Posts
    217
    Post Thanks / Like
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)

    01 SC2 need to replace BCM, anyone have a Tech2 nearby?

    The car is DOHC, 5 speed, sunroof, power windows and locks, all original.

    I've been through all the other possibilities-
    The speedometer works.
    The cruise works (yes I know this is a function of the PCM).
    The car runs fine, no trouble with the ignition or the locks (car has keyless entry).
    The odometer is stuck at 168535 and does not advance.
    The trip odometer is stuck at 0.0 and does not advance.
    There are no OBD2 codes, only the service wrench. I have not had the dealer scan it.

    I bought this car with this condition. The previous owner had a mechanic look at the car and also diagnosed the problem as a bad BCM.

    I'm trying to save some dough anywhere I can. Otherwise I'm looking at ($293 for BCM + labor + $90 flash) = ~ $400 - $500.

    So there are really two questions:

    1.) Rock Auto lists two part numbers, making a designation between the two as either with or without keyless entry. Are there only 2 possible BCMs for the car? OR perhaps, there are only two still available?
    Could I potentially get a JY or new BCM and just plug and play as long as the options matched? Or maybe I have to swap and do the passkey procedure?
    My dad works at the local GM dealership (and has 30+ years as an ASE Master Tech at Goodyear), but he works the parts counter and I feel like the techs are not giving him the full truth of what will work versus what they are willing to do. The techs say I have to buy a new BCM, and have it flashed there (plus labor). I'm wondering if a JY unit would work, but the dealership won't touch that due to liability or theft concerns. The previous owner threw in a JY BCM (part # 21031589) with the car. My car actually came with part # 21031588. Which brings me to my next question.....

    2.) Assuming the JY or Rock Auto unit would work, does any one on here have or have access to a tech 2 scanner that is close somewhat close to upstate South Carolina and that would be willing to help me flash the BCM after install? I know the BCMs on Rock Auto don't match these part #s, but these are the old #s and dad gave me a supercede # that is different and might match one of the Rock Auto units. I just don't have that info in front of me at the moment. I will add it when I get home.

    Any help is appreciated, even if you don't have a Tech2 (Tech II).

  2. #2
    Resident Electromotive Expert importsdontlikeme's Avatar
    Join Date
    Feb 2010
    Location
    Westminster, Maryland
    Posts
    2,937
    Post Thanks / Like
    Blog Entries
    3
    Mentioned
    26 Post(s)
    Tagged
    0 Thread(s)
    I can sell you an Electromotive TecS


    Sent from my iPhone using Tapatalk Pro

    Interested in a solid engine management system? Ask me about Electromotive engine management.

  3. Likes leighv liked this post
  4. #3
    onefast84's Avatar
    Join Date
    May 2007
    Location
    United States
    Posts
    217
    Post Thanks / Like
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Please tell me more. What all can it do?

  5. #4
    Resident Electromotive Expert importsdontlikeme's Avatar
    Join Date
    Feb 2010
    Location
    Westminster, Maryland
    Posts
    2,937
    Post Thanks / Like
    Blog Entries
    3
    Mentioned
    26 Post(s)
    Tagged
    0 Thread(s)
    It's a full standalone ECU, it controls every aspect of the engine and it's 100% PC programmable.


    Sent from my iPhone using Tapatalk Pro

    Interested in a solid engine management system? Ask me about Electromotive engine management.

  6. #5
    onefast84's Avatar
    Join Date
    May 2007
    Location
    United States
    Posts
    217
    Post Thanks / Like
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I knew that much already. But since the car runs like a top already, I'm just trying to get the Odometer to work again, because it bothers me that it does not. I don't suppose it can it run the odometer, too?

    A standalone system might be nice in the future whenever I start really tinkering. I already had you in mind for this.

  7. #6
    Resident Electromotive Expert importsdontlikeme's Avatar
    Join Date
    Feb 2010
    Location
    Westminster, Maryland
    Posts
    2,937
    Post Thanks / Like
    Blog Entries
    3
    Mentioned
    26 Post(s)
    Tagged
    0 Thread(s)
    Well the odometer is driven off the speedo at least in the older cars. Not too sure on the 3 gens though. With a standalone the speedo is still triggered by the factory speed sensor in the trans.


    Sent from my iPhone using Tapatalk Pro

    Interested in a solid engine management system? Ask me about Electromotive engine management.

  8. #7
    onefast84's Avatar
    Join Date
    May 2007
    Location
    United States
    Posts
    217
    Post Thanks / Like
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Correct about the older cars, I saw this up close and personal with my 94 SC2 since I replaced the little red drive gear in the cluster 3 times. And though the Odometer and Speedometer have to be related by sensory input somehow, there is a separation between the final user readable outputs at some point on the 3rd gen. So the Speedometer functions perfectly, but the Odometer is stuck at 168535.

    I know the BCM stores the miles and sends them to the cluster at each startup, and that clearly isn't happening. So, I'm pretty sure the BCM is bad, but I'm not certain on how specific they are to each vehicle, and as a result, how much trouble it would cause if I just plugged in a JY unit (previous owner included one with the car). The dealership says this would be VERY BAD, but I'm not 100% convinced that there isn't a plug and play option, even if it involves a passkey relearn. Yes, a JY BCM would almost certainly not match my current mileage, but at least I could prove that was it before I drop big dollars. And maybe if the miles were close enough, I wouldn't care.

  9. #8

    Join Date
    Nov 2007
    Location
    Innisfil, ON
    Posts
    2,021
    Post Thanks / Like
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    If the miles are close enough you can swap the set (pcm, bcm, ign) and carry on... lol . not sure what they would charge out there for that.
    http://our6thplanet.com/
    40 something saturns.. oh who fraking counts anymore

  10. #9
    onefast84's Avatar
    Join Date
    May 2007
    Location
    United States
    Posts
    217
    Post Thanks / Like
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Yeah, I've heard of that too, but then I either have to swap the door locks too, or have two keys. I have too many keys (and fobs) already. With all the trouble (labor time), it's probably a wash vs. the new BCM at dealer. I could do the swap work myself, but I have better things to do at the time.

  11. #10

    Join Date
    Nov 2007
    Location
    Innisfil, ON
    Posts
    2,021
    Post Thanks / Like
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    Swap the tumblers.... Or the chip on the bottom of the ign is all you actually need to change .
    http://our6thplanet.com/
    40 something saturns.. oh who fraking counts anymore

  12. #11
    onefast84's Avatar
    Join Date
    May 2007
    Location
    United States
    Posts
    217
    Post Thanks / Like
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I did not know it was possible to swap the electronics without changing the whole cylinder. I've swapped tumblers in other locks before, but not in an ignition. I'm guessing it would not be much different. I'm curious now, will have to look at that next time I'm in the JY.

    I still think that it might be possible to swap the BCM without swapping the other stuff (I might be wrong). My main question is the option dependence of the BCM. From my understanding, the BCM on this car only controls keyless entry and the odometer. So clearly there is a difference between keyless and non-keyless entry. This would be nearly impossible to determine in a JY (one could speculate if they found a fob hanging from the ring of the key in to ignition, but people do weird things in the JY, I don't trust it), unless part numbers match, and there have been at least one round of part numbers that supercede the factory equipped units. So, even if it is possible, I'm not sure which BCM part number(s) will work, or if I swap one to test it and it was wrong, if that will lock the PCM, or worse.

  13. #12
    ultraviolet's Avatar
    Join Date
    Aug 2015
    Location
    Denver Metro, CO
    Posts
    44
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by onefast84 View Post
    I did not know it was possible to swap the electronics without changing the whole cylinder. I've swapped tumblers in other locks before, but not in an ignition. I'm guessing it would not be much different. I'm curious now, will have to look at that next time I'm in the JY.

    I still think that it might be possible to swap the BCM without swapping the other stuff (I might be wrong). My main question is the option dependence of the BCM. From my understanding, the BCM on this car only controls keyless entry and the odometer. So clearly there is a difference between keyless and non-keyless entry. This would be nearly impossible to determine in a JY (one could speculate if they found a fob hanging from the ring of the key in to ignition, but people do weird things in the JY, I don't trust it), unless part numbers match, and there have been at least one round of part numbers that supercede the factory equipped units. So, even if it is possible, I'm not sure which BCM part number(s) will work, or if I swap one to test it and it was wrong, if that will lock the PCM, or worse.
    it is indeed possible to swap just the bcm, but it will engage the passlock anti-theft system as you suspect. luckily, it's easy to relearn that system, as indicated below. all 3rd gen bcms support rke, but you would have to have the new bcm programmed to work with your remotes, and i'm not sure if rke is enabled on all bcms (for example on a car with no power locks). i'm also not sure how well other devices on the class 2 bus (like abs and airbag controllers) take to swapping the bcm, but i'm inclined to believe it wouldn't be much of a concern. having swapped pcms in my 2000 sc2 multiple times, i know for a fact that the only procedure required to do that is the one attached.

    http://pcmperformance.com/programmin..._PROCEDURE.pdf

    Passlock – coded lock cylinder
    The Passlock anti-theft system requires the presence of a key in the lock cylinder to enable
    starting. The lock cylinder contains a stationary Hall effect sensor and a rotating magnet. When
    the key is turned in the lock cylinder, the magnet creates a signal on the Hall effect sensor.
    The cylinder then sends a coded signal to the instrument panel cluster (IPC) or body control
    module BCM. If the IPC/BCM receives the expected coded signal, the IPC/BCM will send a
    message over serial data to inform the PCM that the vehicle may be started.
    To perform a relearn on a Passlock system, make sure there is a fully charged battery in the
    vehicle. The battery will be used for 30 minutes without the alternator available for charging.
    Connect a battery charger to the battery to ensure power is available while programming.
    Both the IPC/BCM and PCM must be working and communicating with each other.
    1. Turn ignition on.
    2. Attempt to start the engine, and then release the key to the “ON” position.
    3. Observe the “SECURITY” indicator light. After 10 minutes the “SECURITY” indicator light
    will turn off.
    4. Turn ignition to the “OFF” position, and wait 10 seconds.
    5. Attempt to start the engine, and then release the key to the “ON” position.
    6. Observe the “SECURITY” indicator light. After 10 minutes the “SECURITY” indicator light
    will turn off.
    7. Turn ignition to the “OFF” position, and wait 10 seconds.
    8. Attempt to start the engine, and then release the key to the “ON” position.
    9. Observe the “SECURITY” indicator light. After 10 minutes the “SECURITY” indicator light
    will turn off.
    10. Turn ignition to the “OFF” position, and wait 10 seconds.
    11. Vehicle has now learned the new password. Start the engine.
    12. With a scan tool, clear any trouble codes.
    Last edited by ultraviolet; 05-28-2017 at 07:08 PM. Reason: the bcm is programmed not the remotes
    tethys - 1994 sw2 ll0+mp3 - dark blue and white - current dd, rescued from 4+ years sitting in a field. power nothing.
    mimas - 1996 sw1 l24+mp3 - gold - utility/hauler wagon. previously someone else's parts car.
    rings - 1996 sl2 ll0+mp2 - purple and gold - my first car and former dd. finally repaired after being rear-ended. "soon" to be a lot faster.
    phoebe - 1995 sl1 - silver and teal - got me into wrenching. perpetually a roller. racecar?
    janus - 2000 sc2 l24+mp2 - very sunburned red and purple - yes, sohc. 243kmi on the 2000 sl1 motor/transmission... 32-35mpg. boyfriend's dd.

    russel - 1991 jeep cherokee sport 4.0 i6+aw4 auto+np231/d30/d35 4wd - silver, primer, and rust - body modded 4x4 toy/welding practice -- no lift whatsoever! kicks ass on the trail anyway.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •