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 more than 1 second
Check for DTCs with the HDS
Is DTC B1846 indicated?

YES -Go to step 5

NO -Intermittent failure, the system is OK at this time Check for loose or poor connections
Turn the ignition switch to LOCK (0)
Disconnect power seat control unit connector A (40P)
Disconnect the power seat adjustment switch 12P connector
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 Power Seat Control Unit Connector A (40P) Terminals No 1, No 4, And No 5 Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a 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 a short in the wire

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

YES -Replace the power seat control unit (see POWER SEAT CONTROL UNIT INPUT TEST/REPLACEMENT )

NO -Replace the power seat adjustment switch (see POWER SEAT ADJUSTMENT SWITCH TEST/REPLACEMENT )