Pinpoint Test Ad: DTC U0155 - Lost Communication With Instrument Panel Cluster (Ic) Control Module

WARNING: This page is about a different car, the 2007 Lincoln MKX and 2007 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

AD1 REPEAT THE ON-DEMAND SELF-TEST
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: HCM Self-Test
- Clear the DTCs and repeat the HCM on-demand self-test.
- Is DTC U0155 retrieved again?
1. YES : Go to AD2.
2. NO : The vehicle is operating correctly at this time. The HCM may have temporarily lost communication with the PCM.
AD2 CHECK OTHER MODULES FOR DTC U0155
- Enter the following diagnostic mode on the diagnostic tool: ABS Module Self-Test
- Carry out the on-demand self-test for other modules on the HS-CAN. The PCM, ABS module and restraints control module (RCM), for example, communicate on the HS-CAN.
- Is DTC U0155 retrieved from any other module?
1. YES : REFER to MODULE COMMUNICATIONS NETWORK .
2. NO : Go to AD3.
AD3 CHECK FOR CORRECT HCM OPERATION
- Disconnect the HCM connector.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect the HCM connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new HCM. REFER to Headlamp Control Module (HCM) in this. 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.