2007 Wrangler JK Factory Service Manual Not in the contents tree

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
  • Set Condition:

    If the Anti-Lock Brakes Module fails to receive bus messages from the ECM or PCM for approximately 500 ms.


Possible Causes
  
DTCs RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES
  
CAN C BUS CIRCUITS OPEN OR SHORTED
  
ECM OR PCM POWER AND GROUND
  
ECM OR PCM
  
ANTI-LOCK BRAKES MODULE
  



Diagnostic Test

1. VERIFY DTC IS ACTIVE

NOTE: Verify the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.


Turn the ignition on.
With the scan tool, read and record ABS DTCs.
With the scan tool, read and record Environmental Data (EV Data).
With the scan tool, erase ABS DTCs.
Cycle the ignition switch.
With the scan tool, read ABS DTCs.

Does this DTC reset?

Yes


No

2. CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCs

With the scan tool, read all active DTCs from all CAN C Bus modules.

NOTE: Check for CAN C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.



Does the scan tool display any active DTCs related to the conditions listed above?

Yes
  • Diagnose and repair the DTC(s). Refer to the Table of Contents in the applicable Section.


No

3. VERIFY THAT THE ECM OR PCM IS ACTIVE ON THE BUS

With the scan tool, select ECU View.
Verify that the ECM or PCM is active on the bus.

Is the ECM or PCM active on the bus?

Yes


No

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 or PCM?

Yes


No