DTC U0122: Gauge Control Module Lost Communication With VSA Modulator-Control Unit (VSA Message)

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 ).
If the HDS does not communicate with the VSA modulator-control unit, the VSA indicator dose not go off, and no VSA DTCs are stored, go to symptom troubleshooting for ABS indicator, brake system indicator, and VSA indicator do not go off (see ABS INDICATOR, BRAKE SYSTEM INDICATOR, AND VSA INDICATOR DO NOT GO OFF ).

Clear the DTCs with the HDS.
Turn the ignition switch to LOCK (0), and then back to ON (II).
Wait for at least 6 seconds.
Check for DTCs with the HDS.
Is DTC U0122 indicated?

YES -Go to step 5.

NO -Intermittent failure, the F-CAN communication line is OK at this time. Check for DTCs in the ECM/PCM and the VSA modulator-control unit with the HDS. If F-CAN DTCs are present, check for a loose VSA ground or poor connections at the VSA modulator-control unit or gauge control module. If the connections are good, check the battery condition (see BATTERY TEST ) and the charging system, then clear all DTCs.
Check for DTCs in the ECM/PCM or VSA with the HDS.
Are any DTCs indicated?

YES -Go to the ECM/PCM or VSA indicated DTCs troubleshooting, then recheck.

NO -Go to step 6.
Turn the ignition switch to LOCK (0).
Disconnect the VSA modulator-control unit 47P connector.
Disconnect the gauge control module 32P connector.
Check for continuity between gauge control module 32P connector terminals No. 21 and No. 22 and VSA modulator-control unit 47P connector terminals No. 13 and No. 12 respectively.

Fig 1: Checking Continuity Between Gauge Control Module 32P Connector Terminals No. 21 And No. 22

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Substitute a known-good VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ), and recheck. If the indication goes away, replace the original VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ). If the DTC is still present, replace the gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ).

NO -Repair an open or poor connection in the wire between the VSA modulator-control unit and the gauge control module.