DTC U0155: Lost Communication with Gauge Control Module (Climate Control Unit)

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 back to ON (II), or press the engine start/stop button to select the OFF mode, and then the ON mode.
Do the Self-Diagnostic Function with the HDS (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS ).
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 B-CAN lines between the gauge control module and the climate control unit.
Select B-CAN Control Units Information in the BODY ELECTRICAL menu.
Select Check Connected Units in the B-CAN Control Units Information menu.
Is the gauge control module detected?

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

NO - Go to step 7.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
Disconnect the gauge control module 32P connector.
Disconnect climate control unit connector C (20P).
Check for continuity between the following terminals of the gauge control module 32P connector and climate control unit connector C (20P).
32P: 20P:

No. 29 No. 7

No. 30 No. 8

Fig 1: Checking Continuity Between Terminals Of Gauge Control Module 32P Connector And Climate Control Unit Connector C (20P)
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Go to the gauge control module input test (see GAUGE CONTROL MODULE INPUT TEST ).

NO - Repair an open in the wire(s) between the climate control unit and the gauge control module.