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MSS54HP DME troubleshoot and repair (need help finding a faulty smd component)

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    MSS54HP DME troubleshoot and repair (need help finding a faulty smd component)

    Hi MSS54x gurus,
    I've been trying to troubleshoot and repair a mysterious problem with one of my ebay MSS54HP DME off a wrecked M3. Long story short, the Exhaust side VANOS for this DME doesn't command the 2-channel switch BTS621L1 to activate T_NWA_F (Exhaust vanos advance) basically, the DME leaves exhaust cam around 30-32* right after I start it and increase the idle. This is not an issue with one of my stock DME, so it's not a vanos solenoid issue. I also depin the two wires to the exhaust vanos solenoid while running the DME to probe the outputs, the behavior is at the faulty DME.

    My question would be where does pin 3 (IN1) terminate to on the PCB, I've already replace the BTS621L1. I've probed the other smart two channel switches on the board to verify this was a good known. I'm trying to find the faulty SMD component and replace it as needed. What tools should I be using to find this faulty component, aside a oscilloscope or DVOM.

    Also, I'm a noob when it comes to electronic repairs but am a automotive technician so I'm handy with some tools. Maybe a hammer would fix this DME :-)

    Thank you for reading this,
    -Sam

    Oh for reference here is the datasheet for BTS621L
    Attached Files
    Last edited by Samsonite79; 08-07-2021, 01:31 PM.

    #2
    Okay, finally found the traces leading directly to the CPU, the fault seems to be in the Motorola ZC439512VFT20... Any one have a datasheet for this CPU? Thank you!

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