DTC Troubleshooting: U0155
DTC U0155:
 Heater Control Unit Lost Communication with Gauge Control Module
NOTE: If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN system diagnosis test mode 1.
  1. Clear the DTC with the HDS.
  1. Turn the ignition switch to LOCK (0) and then to ON (II).
  1. Do the self-diagnostic function with the HDS.
  1. Check for DTCs.
Is DTC U0155 indicated?
YES -
Go to Step 5 .
NO -
The system is OK at this time. Check for loose wires or poor connections on the gauge control module and the heater control unit circuit.■
  1. Select UNIT INFORMATION in the BODY ELECTRICAL menu.
  1. Select CONNECTED UNIT in the UNIT INFORMATION menu.
Is the gauge control module detected?
YES -
Substitute a known-good heater control unit, and recheck. If the symptom/indication goes away, replace the original heater control unit. ■
NO -
Go to Step 7 .
  1. Disconnect the gauge control module 32P connector.
  1. Disconnect heater control unit connector B (12P).
  1. Check for continuity between the following terminals of the gauge control module 32P connector, and heater control unit connector B (12P).
    12P:
    32P:
    No. 1
    No. 24
    No. 2
    No. 23

Is there continuity?
YES -
Go to the gauge control module input test.■
NO -
Repair open in the wire between the heater control unit and the gauge control module.■