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08 Mack Pinnacle CXU613 MP8 no start after ignition relay meltdown


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 Hi there Macksters, 

I have an 08 Pinnacle MP8 with an EF Gen 3 autoshift and 682K on the clock. Bought it 6 months ago and I've had a recurring problem with moisture and recently water leaking into and on the EPDM. Unfortunately the Ignition relay was an unsealed variety and must have swallowed some water. Perhaps from energizing it every time I started it, it finally went nuclear and wouldn't start. 

  About 10 fuses were burned on the legs but never popped. I believe the VECU and ABS ECU sustained some damage. I have 2 inactive codes with FMI 9, abnormal update rate, the ECU and TECU. The truck won't start because the VECU doesn't supply the 12 volts for the start enable relay and the TECU doesn't energize the start enable relay, and not allowing a reference for neutral. 

   My question is, when I test for continuity through the J1939/CAN H & L, I have continuity to F11 (pos 12V) and several other circuits that it is connected to through both yellow and green wires. When I disconnect the circuit connectors from the VECU with the data lines still connected there is no continuity to F11, just once the circuit connectors are plugged in. There is continuity when the connector that has the data lines and other circuits is plugged into the ABS ECU. Is the continuity to F11 the interference between the ECU's that is disrupting communication ? Is the VECU and ABS the problem internally that is allowing continuity ? When I unplug the connectors and test continuity through the data line pins and other circuit pins in the ABS ECU there is none, unless the battery cable are connected. Just trying to isolate where the problem is. Any help would be greatly appreciated. Thanks

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