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DTC U0155: HVAC 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 A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

Clear the DTC with the HDS.
Turn the ignition switch to LOCK (0), and then ON (II).
Do the self-diagnostic with the HDS. (see GENERAL TROUBLESHOOTING INFORMATION )
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 HVAC control unit circuit. ■
Select UNIT INFORMATION in the BODY ELECTRICAL menu.
Select CONNECTED UNIT in the UNIT INFORMATION menu.
Is the gauge control module detected?

YES - Substitute a known-good HVAC control unit, and recheck. If the symptom/indication goes away, replace the original HVAC control unit (see HVAC CONTROL UNIT REMOVAL/INSTALLATION ). ■

NO - Go to step 7.
Disconnect the gauge control module 32P connector.
Disconnect HVAC control unit connector A (24P).
Check for continuity between the following terminals of the gauge control module 32P connector and HVAC control unit connector A (24P).
32P: 24P:

No. 19: No. 24

No. 20: No. 23

Fig 1: Checking Continuity Between Terminals Of Gauge Control Module 32P Connector & HVAC Control Unit Connector A
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to GAUGE CONTROL MODULE INPUT TEST . ■

NO - Repair open in the wire between the HVAC control unit and the gauge control module. ■