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Thread: Is my E38 ecm bad

  1. #1
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    Default Is my E38 ecm bad

    I'm back with an issue I've had for several years since the last time i assembled my car. Sent it to my body shop to get painted so haven't had to get into it. Now that the car is assembled, painted, new harness, injectors, map, cam n crank sensor I am still having issues.
    I thought the 6.2 LS3 seem to run well till I installed new Innovate wide-band sensors for my DLG-1 gauge. bank1 show 13.5-13.8 afr, Bank2 shows 17-22+ afr. I have put about 200mi on the engine lately but afraid to drive it for fear of melting something.
    DTC codes are P0204, P0300, and P0358. Well crap!
    I have replace the coil at cyl8 with no change. I put a spark tester inline with coil and no spark, connector has 12v sw and grounds check. Checked continuity on ecm wire from connector to ecm pin and its good. Spark plug looks like its firing.
    I did the same ohm meter tests with #4 injector and all show good. But, spark plug looks like it is not firing.

    Back story: This engine came from a 2010 Camaro SS flood car (fresh water lake) I got at auction. I am using the same ecm the engine/car had os:12633056 vin:2G1FT1EW7A9116154. I change the sensors because they were original to the flooded car.
    Is there a way to test the ecm if its bad? I am lost. Any ideas are appreciated.
    LS3 Manual 6 spd E38 os:12633056
    Texas Speed 1 7/8" headers w/3" exhaust
    Texas Speed cam 229/236 .629/.615 112 LSA
    Hi-Ram intake stock injectors 90mmTB

  2. #2
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    BUMP...still same issue but
    Called PSI were I bought the harness an explained pulse wires ohm out, swapped parts and coil and injector codes are still coil #8 an injector #4 (also no noid fire)
    PSI says its in the tune since all else checks out.
    PSI also sat HP requires a MAP patch to a 2bar setting for SD tune???
    Tune attached.
    I know the log is short but not driving the car till the lean condition is sorted.
    Someone please help.
    Attached Files Attached Files
    LS3 Manual 6 spd E38 os:12633056
    Texas Speed 1 7/8" headers w/3" exhaust
    Texas Speed cam 229/236 .629/.615 112 LSA
    Hi-Ram intake stock injectors 90mmTB

  3. #3
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    UPDATE!!
    All is fixed no codes and headed to a dyno Friday.
    Problem was with a BRAND NEW PSI harness. The pins 39 and 71 for E38 J2 ecm connector were not seated and 39 (injector 4 pulse) and 71 (coil 8 pulse) was not push in all the way, so barely touching causing the intermittent open code P0204, P0354. Even though I had ohm the wire (not taking the connector apart) and ohm the injector and coil, I saw no smoking gun. It wasn't till I pulled the pin cap on J2 that I saw the problem. All is fixed and the LS3 runs pretty good for a newby tune. Who would think of that kind of problem on a new harness.
    LS3 Manual 6 spd E38 os:12633056
    Texas Speed 1 7/8" headers w/3" exhaust
    Texas Speed cam 229/236 .629/.615 112 LSA
    Hi-Ram intake stock injectors 90mmTB

  4. #4
    Joe (Moderator) joecar's Avatar
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    Good to hear you got it running

    Lesson learnt is to also visually inspect

  5. #5
    Lifetime Member minytrker's Avatar
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    Quote Originally Posted by 5557nut View Post
    UPDATE!!
    All is fixed no codes and headed to a dyno Friday.
    Problem was with a BRAND NEW PSI harness. The pins 39 and 71 for E38 J2 ecm connector were not seated and 39 (injector 4 pulse) and 71 (coil 8 pulse) was not push in all the way, so barely touching causing the intermittent open code P0204, P0354. Even though I had ohm the wire (not taking the connector apart) and ohm the injector and coil, I saw no smoking gun. It wasn't till I pulled the pin cap on J2 that I saw the problem. All is fixed and the LS3 runs pretty good for a newby tune. Who would think of that kind of problem on a new harness.
    not uncommon with psi harness

  6. #6
    Senior Member
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    Wow, I thought it was just me. I don't think PSI is alone though, it seems I have to repair almost any aftermarket harness I come across lately :( What a pain to have to chase what you cannot see. Shoot, even then, the chinese terminals don't have the little tiny spring inside the terminal like the factory did. That's why those terminals are .78usd vs .06usd each in bulk.

  7. #7
    Lifetime Member minytrker's Avatar
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    I use only Spartech harness. They are hand made on a real engine/trans and then they run the engine with a laptop connected checking it. They use OEM quality terminals and wire not cheap imported stuff. I could fill up a dumpster with bad new harness we have removed from other companies. I have never had to remove a Spartech harness.

  8. #8
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    Hiya,
    Now that I think a bit. I have never had an issue with anything from Speartech, good call

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