DTC U0104: Gauge Control Module Lost Communication With ACC Unit (ACC Frame)

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 ACC unit, the ACC indicator stay on, and no ACC DTCs are stored, go to symptom troubleshooting for ACC indicator does not go off, and no DTCs are stored (see DTC 199: ACC UNIT PROGRAMMING ERROR ).

Clear the DTCs 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.
Wait for at least 6 seconds.
Check for DTCs with the HDS.
Is DTC U0104 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system is OK at this time. Check for loose or poor connections between the gauge control module and the ACC unit.
Check for ACC DTCs with the HDS.
Are any DTCs indicated?

YES -Go to the ACC indicated DTCS TROUBLESHOOTING , then recheck.

NO -Go to step 6.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
Disconnect the ACC unit 20P connector.
Disconnect gauge control module connector A (32P).
Check for continuity between gauge control module connector A (32P) terminals No. 13 and No. 14 and ACC unit 20P connector terminals No. 20 and No. 10 respectively.

Fig 1: Checking For Continuity Between Gauge Control Module Connector A (32P) Terminals No. 13 And No. 14 And ACC Unit 20P Connector Terminals No. 20 And No. 10
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Substitute a known-good ACC unit (see ADAPTIVE CRUISE CONTROL (ACC) UNIT REMOVAL/INSTALLATION ), and recheck. If the indication goes away, replace the original ACC unit. 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 F-CAN wire(s) between the ACC unit and the gauge control module.