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U0100 - Lost Communication With Engine Control Module/Powertrain Control Module

For a complete wiring diagram, refer to appropriate Wiring Diagram.

Possible Causes
CAN C Bus(+) CIRCUIT D51 SHORT TO VOLTAGE
CAN C Bus(-) CIRCUIT D52 SHORT TO GROUND
DTCs RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES
TIPM NOT CONFIGURED CORRECTLY
ECM/PCM POWER AND GROUND
ECM/PCM
ANTI LOCK BRAKE MODULE

Test Step 1 - Verify DTC Is Active 

NOTE:

Ensure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.

Is this DTC active?

Yes

No

Test Step 2 - Test for Any of the Following Active DTCs 

NOTE:

Test for TIPM configuration, CAN C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.

Does the scan tool display any active DTCs to the conditions listed more than?

Yes

No

Test Step 3 - Verify that the ECM/PCM is Active on the Bus 

Is the ECM/PCM active ON the Bus?

Yes

No

Test Step 4 - Test for Additional Communication Related DTCs 

Is there more than one module with active DTCs "Logged Against" the ECM/PCM?

Yes

No

Test Step 5 - Clear DTC in Module Setting Fault 

Is this DTC still active?

Yes

No

Test Step 6 - Cycle Ignition 

Does this DTC become active?

Yes

No

Test Step 7 - Test for Additional Lost Communication Faults 

Does the TIPM and other CAN C Bus modules show Lost Communication with the remaining CAN C Bus modules?

Yes

No

Test Step 8 - CAN C Bus (+) Circuit Short to Voltage 

Is the voltage more than 5 volts?

Yes

No

Test Step 9 - CAN C Bus (-) Circuit Short to Ground 

Is the resistance less than 10K Ohms?

Yes

No