Rear Up-Down Position Sensor:

Remove the driver's power seat. See FRONT SEATS .
NOTE: Be careful to not scratch the interior trim.
Disconnect the 5P connector from the rear up-down position sensor and the 12P connector from the power seat control unit.
Check for continuity between the No. 2 terminal of the rear up-down position sensor and C12 terminal of the power seat control unit.

Fig 1: Checking Continuity At Power Seat Control Unit 12P Connector C
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES -Go to step 4.
2. NO -Repair open in the BRN/BLK wire.
Check for continuity between the No. 1 terminal of the rear up-down position sensor and C11 terminal of the power seat control unit.

Fig 2: Checking Continuity
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES -Go to step 5.
2. NO -Repair open in the RED/BLK wire.
Reconnect the 5P and 12P connectors.
Check for voltage between the No. 5 terminal of the rear up-down position sensor and body ground.

Fig 3: Checking Voltage
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 5 V?
1. YES -Go to step 7.
2. NO -Repair the open or the short to ground in the BRN/WHTwire.
Check for voltage pulse between the No. 1 terminal of the rear up-down position sensor and body ground when the rear up-down switch moves up and down.

Fig 4: Checking For Voltage Pulse
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Does voltage pulse from 0 to about 5 V alternately?
1. YES -Replace the power seat control unit.
2. NO -Check for a short in the wire. If the wire is OK, faulty rear up-down position sensor; replace the rear up-down motor assembly.