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Thread: E39A Pinout chart-anyone?

  1. #1

    E39A Pinout chart-anyone?

    I have found a chart for the the E39A ECM in an LTG here: https://www.chevrolet.com/content/da...19328839-1.pdf
    But there are a lot of pins left out of this standalone wiring harness. Does anyone have access to or know where I could find the pinout chart for an LHU?

  2. #2
    There are many different Pinouts for the E39A.
    It depends on the engine AND the vehicle.

    Even for the LHU I already found four different Pinouts.
    Depending on which harness and which OS you have.

    What makes it tricky (and dangerous) is that the pinouts are slightly different and you have to take a really close look...

    The Pinout for 12 Buick Regal GS with LHU is somewhere here in Forum.

    Do you still try to make it work with that messed up aftermarked wiring loom?
    Last edited by BadCop; 02-24-2016 at 12:06 AM.

  3. #3
    I have no choice but to make it work with the harness I have and everything works EXCEPT the speedometer. I am looking for the pin for ABS brakes or wheel speed sensor so I can try connecting to that. I looked at the pinout for the 2012 GS and it is curious how some pins are not used in that application but are used in the LTG application. It's like all pins have a use but not all in one engine. I just need to get a vehicle speed or the engine will not make full power. You would think there would be a patch for that similar to a VATS patch but no.
    Last edited by marksawatsky; 02-24-2016 at 08:59 AM.

  4. #4
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    Quote Originally Posted by marksawatsky View Post
    I have no choice but to make it work with the harness I have and everything works EXCEPT the speedometer. I am looking for the pin for ABS brakes or wheel speed sensor so I can try connecting to that. I looked at the pinout for the 2012 GS and it is curious how some pins are not used in that application but are used in the LTG application. It's like all pins have a use but not all in one engine. I just need to get a vehicle speed or the engine will not make full power. You would think there would be a patch for that similar to a VATS patch but no.
    Mark, here we go with another form of communication. After reading all this, and looking at the diagram again it occurs to me one of the things, many things, we do NOT know is just what, if anything does the VCM do with the VSS signal from the transmission BEFORE it goes to the Speedometer? It could very well NEVER get to the speedometer from the inside the VCM. I may well go out of the VCM and onto the CAN bus (which our SWAPPED cars do NOT have) and go to other modules. We need to start at the speedometer, if the E39a cars have one and not a DIC or something digital, and work our way back to a signal source.
    Some how the VCM needs to know the vehicle is not standing still, does not have the clutch pedal depressed, nor the brake pedal depressed.
    Other than that, you're good to go.

  5. #5
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    Ebay says the 2013 Regal does have an actual speedometer with a sweeping needle.

    Del Long

  6. #6
    I have studied the installation instructions for the GM standalone LTG engine, which in theory is similar to my LHU, and it says that the ECM is looking for a 12 pulse per revolution digital signal into the ecm, then the speedometer is hooked to pin X1 pin 43. See instructions here: https://www.chevrolet.com/content/da...19328839-1.pdf

  7. #7
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    Hi Mark, i dont know if you sorted this problem already. but i believe you might possibly be putting the speedo wire onto the wrong pin.
    The 2013 V6 Camaro diagram says ECM X2 Pin 8. and another diagram for another vehicle (using E39A Ecu also lists the same pin)
    93782774_219337766164687_7673555383268409344_o1.jpg