DTC B1846: Power Seat Front Up-Down Switch Circuit Malfunction

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 DTCs with the HDS.
Turn the ignition switch to LOCK (0), and then back to ON (II).
Operate the front up-down switch in each direction for at least 1 second.
Check for DTCs with the HDS.
Is DTC B1846 indicated?

YES -Go to step 5.

NO -Intermittent failure, the driving position memory system is OK at this time. Check for loose or poor connections at the power seat control unit connectors.
Turn the ignition switch to LOCK (0).
Disconnect power seat control unit connector A (40P).
Disconnect the power seat adjustment switch 12P connector and C901 under the driver's seat.
Check for continuity between body ground and power seat control unit connector A (40P) terminals No. 1, No. 4, and No. 5 individually.

Fig 1: Checking Continuity Between Body Ground And Power Seat Control Unit Connector A (40P) Terminals No. 1, No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair short to ground in the wire.

NO -Go to step 9.
Check for continuity between these power seat control unit connector A (40P) terminals:
- No. 1 and No. 4
- No. 1 and No. 5
- No. 4 and No. 5
Fig 2: Checking Continuity Between Power Seat Control Unit Connector A (40P) Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair short in the wire.

NO -Go to step 10.
Do the power seat adjustment switch test (see POWER SEAT ADJUSTMENT SWITCH TEST/REPLACEMENT ).
Is the switch OK?

YES -Replace the power seat control unit.

NO -Replace the power seat adjustment switch.