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Home >> Jeep >> 2025 >> Compass Latitude >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> Body Control Module (BCM) - DTCS U0102-00 To U0403-00 >> DTC Troubleshooting >> U01B0-00 Lost Communication With Battery Monitor Module >> Diagnostic Test

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. With the scan tool, read Body Control Module (BCM) DTCs and record on the repair order.
    2. Record the Environmental Data.
    3. With the scan tool, erase DTCs.
    4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    5. With the scan tool, read BCM DTCs.

      Did the DTC return?

      Yes 

      • Go To  2

      No 

  2. CHECK FOR VOLTAGE ON THE (A916) FUSED B(+) CIRCUIT 
    1. Turn the ignition off.
    2. Disconnect the Intelligent Battery Sensor (IBS) harness connector.
    3. Turn the ignition on.
    4. Measure the voltage on the (A916) Fused B(+) circuit at the IBS harness connector.

      Is the voltage below 9.0 volts?

      Yes 

      • Remove and inspect Fuse F90 (5A) for an open.
      • If Fuse Is Okay:  Repair the open in the (A916) Fused B(+) circuit. Install Fuse F90 (5A).
      • If Fuse Is Open:  Repair the short to ground in the (A916) Fused B(+) circuit. Replace Fuse F90 (5A).
      • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

      No 

      • Go To  3
  3. CHECK THE (Z901) GROUND CIRCUIT FOR AN OPEN 
    1. Turn the ignition off.
    2. Measure the resistance between ground and the (Z901) Ground circuit at the IBS harness connector.

      Is the resistance above 3.0 Ohms?

      Yes 

      • Repair the open in the (Z901) Ground circuit.
      • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

      No 

      • Go To  4
  4. CHECK THE (D401) LIN BUS 1 CIRCUIT FOR AN OPEN 
    1. Disconnect the BCM C4/D harness connector.
    2. Measure the resistance of the (D401) LIN Bus 1 circuit between the IBS harness connector and the BCM C4/D harness connector.

      Is the resistance above 3.0 Ohms?

      Yes 

      • Repair the open in the (D401) LIN Bus 1 circuit.
      • Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

      No 

      • Go To  5
  5. CHECK FOR VOLTAGE ON THE (D401) LIN BUS 1 CIRCUIT 
    1. Reconnect the BCM C4/D harness connector.
    2. Turn the ignition on.
    3. Measure the voltage on the (D401) LIN Bus 1 circuit at the IBS harness connector.

      Is there any voltage present?

      Yes 

      No 

      • Go To  6
  6. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all BCM harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Perform a terminal drag test on each connector terminal to verify proper terminal tension.

      Repair any conditions that are found.

    5. Reconnect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. With the scan tool, erase DTCs.
    9. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
    10. With the scan tool, read BCM DTCs.

      Did the DTC return?

      Yes 

      No