PCM problems, how to test circuits Cummins

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Derek Norsworthy

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Ram Year
2017
Engine
3.6
2011 Ram 3500 6.7 dually PCM intermittent power input, various sensor circuits high and low, no comms with PCM from various modules, AllData only helps if I have a PCM connector breakout box 8815.
Can someone show me how to find these circuits myself ?
Looking for 3 PCM ground circuits, 3 PCM Fused ignition circuits, 2 B+ fused circuits(Found these 2 on C2 connector)
Where the breakout box plugs in would be very beneficial but there is no trace of a manual or video of anyone using one of these. Also there is no manual or direction on anyones website about it.

Problems currently are no wait to start lamp on dash, service 4 wheel drive, service battery, security light on, no engine turn over, no CAN bus.

Little update.
Made me a test probe and started checking all pins on C2 harness(Unplugged) with +12v on test light clip looking for grounds other than specified grounds in schematics and I found 8 pins that light up showing a complete / somewhat complete circuit.

Ignition Control Run/Start pin 71 has power with key on.
Brake Signal 2 pin 66, always has short to ground or complete circuit with key off or on.
TRS T41 Signal pin 48, same
TRS T4 Signal pin 28, same
TRS T42 Signal pin 30, same
Can C+(pin 35) and Can C-(pin18) showing 2.7 volts all the time even after key off for over 45 minutes
Actuator High Data link(pin 34) and Actuator low Data link(pin 17) showing complete circuit.


About to test pins on C1 connector today as well as resistance on all pins.

C1 Circuits tested today, just checked for ground. Key off on these tests.
EGR Bypass(pin 45) grounded
Gen Field Control(pin 28) grounded Can someone tell me what this is?
Oil Pressure Signal(pin 18) grounded

New TIPM and 2 new batteries installed, disconnected cleaned and greased all wiring harnesses under seats, in doors, ABS module, TIPM module, TCM module, Trailer Brake Module, C1 and C2 on PCM, and this 30-40 pin harness connector just under windshield( I would love to know what all this goes too, I cant find it on alldata. Cleaned and greased connector under driver wheel well(Gonna check this again for corrosion)
 

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Last edited:

HarryS

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chri5k

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Did you check / clean the connector behind the left wheel well liner? That is a major one that connects the engine bay to the cabin components and gets splashed with water in some circumstances.
 

HarryS

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Derek Norsworthy

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Did you check / clean the connector behind the left wheel well liner? That is a major one that connects the engine bay to the cabin components and gets splashed with water in some circumstances.
Cleaned with OE cleaner and greased it up. Will look again at this.
 
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Derek Norsworthy

Junior Member
Joined
Oct 12, 2020
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Valrico
Ram Year
2017
Engine
3.6
Did you check / clean the connector behind the left wheel well liner? That is a major one that connects the engine bay to the cabin components and gets splashed with water in some circumstances.
checked and cleaned it up. Looks good.
 
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