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Thread: 2016 challenger in a 71 Cuda - No Start

  1. #1
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    2016 challenger in a 71 Cuda - No Start

    I?ve got a customer?s car here that?s really testing my patience.

    I had hptuners do the pcm modification, but they don?t allow you to disable SKIM. So I sent it to Moparking on this forum and supposedly it?s removed. Still no start.

    I have codes for a bunch of Circuit Highs on ECT, IAT and TPS. Harness brand unknown. More on that later, but after I delete codes (like the MDS codes), they don?t stay off? Is there a special trick to disabling Dodge codes than unchecking the boxes and doing a Write Calibration? There?s no option to Write Entire.

    I build harnesses all the time, but I can?t find a pin out for this application. I?d like to verify the Sensor Low Reference wiring also.

    So in conclusion, three issues:
    1. No start
    2. Codes aren?t deactivating
    3. Possible low reference issue, considering I have several sensors with codes for Circuit High

  2. #2
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    If the codes read as "(Permanent)" next to each one, those are not currently occurring but had a fault at some point. They will only clear once you have completed a full cold to hot drive cycle and restart the car. You cannot clear permanent codes with any other method, not even reflashing a new tune. If they show as "(Pending)" that means the current drive cycle had the fault.

    A lot of permanent codes get set when you turn the ignition on without the sensors plugged in. Same with "High Circuit" fault, that is typically set when sensor isn't plugged in.
    Last edited by 06300CSRT8; 05-14-2019 at 02:52 PM.

  3. #3
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    what year PCM? Newer cars send the start signal over CAN BUS, there is a setup screen in the "System" section of the tune to enable/disable this feature. If it is enabled but you have rigged up a standard relay to start, the ECU wont be happy.

  4. #4
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    Quote Originally Posted by 06300CSRT8 View Post
    If the codes read as "(Permanent)" next to each one, those are not currently occurring but had a fault at some point. They will only clear once you have completed a full cold to hot drive cycle and restart the car. You cannot clear permanent codes with any other method, not even reflashing a new tune. If they show as "(Pending)" that means the current drive cycle had the fault.

    A lot of permanent codes get set when you turn the ignition on without the sensors plugged in. Same with "High Circuit" fault, that is typically set when sensor isn't plugged in.
    Hmm. I have to double check.

    Sensors were definitely plugged in.

    What?s interesting is that they read correctly on the Scanner.. but still set codes for high circuit failure?

    I got some schematics from a buddy?s body shop for the engine and i?ll be checking the pin out to each sensor continuity as well as the pin location in the ECM being correct. They vary between a mopar performance pcm and a stock production pcm. Dodge sure doesn?t make it easy.
    Last edited by cjsgarage; 05-15-2019 at 02:35 AM.

  5. #5
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    Quote Originally Posted by 06300CSRT8 View Post
    what year PCM? Newer cars send the start signal over CAN BUS, there is a setup screen in the "System" section of the tune to enable/disable this feature. If it is enabled but you have rigged up a standard relay to start, the ECU wont be happy.
    2016 Challenger R/T non supercharged PCM.

    Start signal over CAN is set to disabled from system menu. So is most everything else, since this car has a manual 5speed and no other modules on the system.

    Would this be anything like what I?m experiencing if it was set up wrong?
    Last edited by cjsgarage; 05-15-2019 at 02:33 AM. Reason: add quotes

  6. #6
    Most of those codes have the sensor ground in common. I would start there. Then check 5 volt output from PCM. If you need schematics inbox me.

  7. #7
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    Quote Originally Posted by Kmoney View Post
    Most of those codes have the sensor ground in common. I would start there. Then check 5 volt output from PCM. If you need schematics inbox me.
    I downloaded some from alldata. Hopefully those work. I did see that the grounds are in common on the sensors, but the only schematic I found (at first) was to a Mopar Performance PCM.. and the common sensor ground did not have continuity to the pin according to THAT diagram. I pulled the whole harness and I?m going to go pin by pin on the ECM.

  8. #8
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    I?ve got C1 all done. But there?s 3 pins that are not present that I?m not sure what they went to:
    C1 42 brn/wht sensor ground
    C1 48 brn/db 5V supply
    And
    C1 54 brn/tn sensor ground

    Anyone else have any schematics?

    I found that the IAT/ECT/EOT share a ground and they are indeed pinned into a ?sensor ground? in the ECM.. but I?m wondering if they?re pinned to the correct sensor ground. It doesn?t seem right that all three should only go to one ground.. shouldn?t they each get their own ground if the pcm is monitoring them? Or is that only for GM?