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

WARNING: This page is about a different car, the 2006 Honda Odyssey and 2005 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

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 front up-down switch in each direction for more than 2 seconds.
Check for DTCs with the HDS.
Is DTC B1846 indicated?
1. YES - Go to step 5.
2. 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 the power seat control unit connector A (40P).
Disconnect the power seat adjustment switch 12P connector.
Check for continuity between the power seat control unit connector A (40P) No. 1, No. 4, No. 5 terminals and body ground.

Fig 1: Checking Continuity Between Power Seat Control Unit Connector A (40P) Terminals 1, 4, 5 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Repair a short in the wire.
2. NO - Go to step 9.

Check for continuity between the following terminals of the power seat control unit connector A (40P).

No. 1 <-> No. 4

No. 1 <-> No. 5

No. 4 <-> No. 5

Fig 2: Checking Continuity Between Power Seat Control Unit Connector A (40P)

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Repair a short in the wire.
NO - Go to step 10.

Perform the power seat adjustment switch test (see SWITCH TEST/REPLACEMENT ).
Is the switch OK?
1. YES - Replace the power seat control unit.
2. NO - Replace the power seat adjustment switch.