U0100-LOST COMMUNICATION WITH ECM/PCM
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the ignition on.
Battery voltage between 10 and 16 volts.
IOD fuse installed.
FCM is configured correctly.
- Set Condition:
Bus messages not received from the ECM/PCM for approximately 2 to 5 seconds.
| Possible Causes |
| CAN B OR CAN C BUS CIRCUITS OPEN OR SHORTED |
| DTCS RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES |
| FCM NOT CONFIGURED CORRECTLY |
| ECM/PCM POWER AND GROUND |
| ECM/PCM |
| MODULE THAT SET THIS DTC |
Diagnostic Test
1. VERIFY DTC IS ACTIVENOTE: Ensure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.
With the scan tool, read active DTCs.
Is this DTC active?
Yes
- Go To 2
No
- Refer to the Stored Lost Communication test procedure. Refer to the table of contents in this section.
2. CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCS
With the scan tool, read all active DTCs from all modules.
NOTE: Check for FCM configuration, CAN B or C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.
Does the scan tool display any active DTCs to the conditions listed above?
Yes
- Diagnose and repair the DTC. Refer to the Index for a complete list of the symptoms.
No
- Go To 3
3. VERIFY THAT THE ECM/PCM IS ACTIVE ON THE BUS
Turn the ignition on.
With the scan tool, select Network View and select Advanced.
Verify that the ECM/PCM is active on the bus.
Is the ECM/PCM active on the bus?
Yes
- Go To 4
No
- Refer to the No Response test procedure. Refer to the table of contents in this section.
4. CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCS
With the scan tool, select Network View and select Advanced.
Is there more than one module with active DTCs “Logged Against” the ECM/PCM?
Yes
- Replace/update the ECM/PCM in accordance with the service information.
- Perform the appropriate VERIFICATION TEST.
No
- Replace/update the module that set this DTC in accordance with the service information.
- Perform the appropriate VERIFICATION TEST.