DTC B1847: Power Seat Rear 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 OFF, and then back ON (II).
Operate the rear up-down switch in each direction for more than 1 second.
Check for DTCs with the HDS.
Is DTC B1847 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 connector.
Turn the ignition switch OFF.
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. 3, and No. 23 individually.

Fig 1: Checking Continuity Between Body Ground And Power Seat Control Unit Connector A (40P) Terminals No. 1, 3 And 23
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. 3
- No. 1 and No. 23
- No. 3 and No. 23
  
  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.
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.