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  1. dndj

    LB7 CRANKS BUT NO START

    I had another thought about this last night, considering all the data you provided. Given you've swapped all the main modules (ECM, BCM, FICM...) and checked everything over very well, I'm leaning toward some sort of a intermittent wire break in a wiring harness, especially since the...
    • dndj
    • Post #19
    • Forum: LB7
  2. dndj

    LB7 CRANKS BUT NO START

    I did review, sorry I missed the part about the CKP and CMP. Hope you get it figured out, you've covered all the bases I can think of other than putting a scope directly on pin 94 of FICM C2 to take a look at the engine speed signal sent from the ECM.
    • dndj
    • Post #10
    • Forum: LB7
  3. dndj

    LB7 CRANKS BUT NO START

    The FICM needs to see an engine speed signal from the ECM. The +12v reference on the CKP and CMP is shared, if it's shorted to ground neither will work and the engine won't start. Normally this is checked by observing the engine RPM while cranking. RPM will be zero if this is the case...
    • dndj
    • Post #8
    • Forum: LB7
  4. dndj

    Need info on a P0380 code

    There are actually 2 relays inside the black plastic block looking thing on rear of the drivers side valve cover, but I replaced my whole module. One interal relay is for the intake heater, the other for the glow plugs. If one is not working correctly the other may be not too far behind...
    • dndj
    • Post #7
    • Forum: LB7
  5. dndj

    2008 Yukon 2500 Wet Floor

    Dry everything out with a hair dryer. Crawl inside with a flashlight while a friend with a garden hose runs water over all suspect areas - cowl, front window seals, door seals.
  6. dndj

    Need info on a P0380 code

    Federal or Cali emissions LB7? If federal, it's your glow plug relay. On a federal emissions truck, P0380 is a glow plug relay failure, stuck closed or not making connection. All 8 glow plugs are connected in parallel to the glow plug relay and no codes will show up with any open glow...
    • dndj
    • Post #4
    • Forum: LB7
  7. dndj

    Lbz starter cranks in on position

    I'm kind of thinking along the lines of LBZ's comment. Your starter relay contacts may have been stuck together, fiddling around in the fusebox while you were changing 5* may have been just enough to knock it loose. Problem may come back. Good to have one of the rectangular relays as a spare...
  8. dndj

    Lbz starter cranks in on position

    Hmm ok I misunderstood which one you replaced, I was assuming one of the rectangular relays. If you're talking about one of the 3 larger square body relays, the one marked 5* in the last black and white picture? That is labeled EDU on my truck. This relay runs the FICM and energized by the...
  9. dndj

    Lbz starter cranks in on position

    Those rectangular relays (horn, DRL, A/C compressor, etc) function fine when plugged in either direction since the flyback/snubber component in parallel with the relay coil is likely just a resistor, not a diode. My GM FSM schematic shows a snubber resistor, although I will admit I haven't...
  10. dndj

    Could a BCM cause this?

    Check battery voltage at the terminals when the truck fails (no lights, no start) while there's some load on it - while cranking or with headlights on. Since you said it cranked slow after jumping, I'm betting on bad battery. Possible that there's an intermittent problem internal to the...
  11. dndj

    Where to buy v2 ?

    I bought my V2 about 3 months ago from PPEI, still on their website currently. Efilive appears to have taken down the Flashscan V2 from their website in favor of the V3 now, but their support policy states they will support it in their software for 3 years past their "End of Sale" notice...
  12. dndj

    2001 lb7 ECM Trouble ?

    From what you describe, I would be looking for a reman ECM with a clean 2001 stock tune, or find someone nearby who is willing to do a temporary swap for testing purposes.
  13. dndj

    Truck stolen.

    Damn I hate thieves. :mad::mad::mad:
  14. dndj

    I'm going to have to retire.

    Prayers for you and your wife Mike. Loved your stories when we talked on the phone, like we were long time friends even though it was my first purchase. Glad to hear about Evan too.
  15. dndj

    2022 Duramax?

    In older cars with breaker points style ignition, you could burn out the ballast resistor if the points were closed and the ignition was left on for long periods. I don't think this is an issue with modern electronic ignition systems other than normal battery drain from any accessories.
  16. dndj

    LB7 electrical gremlins

    Yes. This should be ground G203.
  17. dndj

    LB7 electrical gremlins

    Agree about grounding. Referencing my 2003 schematic, the OBD2 connector behavior the OP noted is a big clue. Pin 4 and 5 are both grounds in the OBD2 connector, pin 4 connects to G200 which is a ground lug under the dash on the right hand side. Pin 5 connects to G203 which is a ground lug...
  18. dndj

    Front axle actuator

    Check for codes, if you haven't already. There may be codes from the 4x4 system even if the check engine light isn't on.
  19. dndj

    Boost valve question

    I've seen 30 psi peaks (pre-IC) with 50-60 degree ambient temps and a 100-120hp Efilive tune. Stock LB7 IHI turbo w/PPE boost valve.
    • dndj
    • Post #16
    • Forum: LB7
  20. dndj

    06 chevy with Alison tranny

    The ECM sets P0700 when the TCM (Transmission Control Module) has a code stored. You need a scanner to pull the codes from the TCM, this is the code Mike needs. Many of the cheap OBD2 readers won't pull the TCM codes.
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