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PCC1302 PowerCommand Code 781 – ECM CAN Datalink Has Failed

Communication between the engine control module (ECM) and the generator set control is severed.

PCC1302 Command


2023 Cummings InPower 14.5 Pro

PowerCommand Diagnostic 9 Pin Adapter Cable for InPower


Possible Causes:
1. The Engine ECM has lost power or failed
2. The CAN datalink has failed

Diagnosis and Repair:
1. The Engine ECM has lost power or failed
a. Check the wiring from the base board.
b. Keyswitch control relay is a normally open relay. Ensure that B+ is available at the relay input, then measure the voltage output. If there is a B+ at both the input and
output of the Keyswitch control relay, the relay is not faulty. If B+ is noted at the input but not at the output of the Keyswitch control relay, replace the relay.
c. Connect to the engine ECM with InPower and/or Insite, to verify that the ECM is functioning properly and is communicating with the CAN-LINK network. Refer to the
engine service manual for ECM troubleshooting procedures, if the ECM is faulty,replace.
2. The CAN datalink has failed
a. There is a defective datalink harness connection, or open circuit; inspect the datalink harness and connector pins. Also check the shield ground connection.

b. Check the terminating resistors. With connector disconnected from the base board and the engine datalink connection disconnected from the ECM control, measure
resistance between pins (60 ohms is satisfactory). If the resistance is not 60 ohms,check the terminating resistors. Each of the two terminating resistors should be 120
ohms, replace if not 120 ohms.