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  1. #1

    Default Location of ECM in '90 V2500 Suburban

    My good ol' truck started running rich so I read the codes and turns out it had a MAP sensor voltage low code. I replaced the MAP sensor and all was good for a while. Then the problem came back, same code. Seems to me that all that's left is the wires connecting the MAP sensor to the ECM or the ECM itself. Sensor still tests good with voltmeter. I would like to test from both ends of the wires and replace as necessary, but I don't know where the ECM is actually located. The wires are all bundled together and it's tough to tell where they go. If anyone knows it'd save me some looking around. thanks

  2. #2
    Legend unplugged's Avatar
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    Default Where is the ECM on a GM Truck

    On mine it is behind the glove box. Remove the glovebox tray for access. Big ugly silver thingy.

    AutoZone has a pretty good component locator:
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  3. #3


    Yep, it in dash on the right side. Rather than checking the wires you could watch the feedback on a scanner. If the feedback data changes <use a MightyVac> you know the wires have continuity.

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  4. #4


    Thanks! The wire carrying the signal from the MAP sensor to the ECU was intermittent so I ran a new wire and we're good. The voltage low trouble code is not reappearing.

    Unfortunately, that was not the main problem. I'm going to start a new thread in the proper Chevy Suburban category since it appears to be a completely separate issue.

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