Pinpoint Test Ai: DTC U0140 - Lost Communication With Body Control Module (Gem)

AI1 RETRIEVE THE RECORDED DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND INSTRUMENT CLUSTER (IC) SELF-TESTS
- Check for recorded instrument cluster (IC) DTCs from the continuous and on-demand self-tests.
- Is DTC B1318 recorded?
1. YES : REFER to DTC Charts .
2. NO : Go to AI2.
AI2 RECHECK THE INSTRUMENT CLUSTER (IC) DTCs
- Repeat the instrument cluster (IC) self-test.
- Clear the DTCs.
- Is DTC U0140 still present?
1. YES : Go to AI3.
  For all other DTCs, REFER to DTC Charts .
2. NO : The system is operating correctly at this time. The DTC may have been set due to high network traffic.
AI3 RETRIEVE THE RECORDED DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND AUDIO CONTROL MODULE (ACM) AND HEATING VENTILATION AIR CONDITIONING (HVAC) MODULE SELF-TESTS
- Check for recorded ACM and HVAC module DTCs from the continuous and on-demand self-tests.
- Is DTC U0140 recorded?
1. YES : REFER to MODULE COMMUNICATIONS NETWORK article to diagnose no communication with the SJB.
2. NO : Go to AI4.
AI4 CHECK THE NETWORK OPERATION
- Carry out the network test.
- Does the SJB pass the network test?
1. YES : Go to AI5.
2. NO : REFER to MODULE COMMUNICATIONS NETWORK article to diagnose no communication with the PCM.
AI5 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and verify that the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new SJB. REFER to MULTIFUNCTION ELECTRONIC MODULES article. TEST the system for normal operation.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.