Door Unit

Remove the door multiplex control unit from the driver's door, and disconnect its connectors.
Inspect the connector and socket terminals to be sure they are all making good contact.
- If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
- If the terminals look OK, go to step 3.
  
  Fig 1: Identifying Door Multiplex Control Unit Connector A
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
  
  Fig 2: Identifying Door Multiplex Control Unit Connector B
  Courtesy of AMERICAN HONDA MOTOR CO., INC.

Reconnect the door multiplex control unit connector, and make these input tests at the connectors.

If any test indicates a problem, find and correct the cause, then recheck the system.

If all the input tests prove OK, go to step 4.

CONTROL UNIT INPUT TEST (DOOR UNIT - RECONNECTED)

Cavity	Wire	Test condition	Test: Desired result	Possible cause if result is not obtained
A1	WHT/YEL	Under all conditions	Check for voltage to ground: There should be battery voltage.	Blown No. 13 (7.5 A) fuse in the passenger's under-dash fuse/relay box Faulty passenger's fuse/relay box An open in the wire
A2	GRN/WHT	Ignition switch ON (II)	Check for voltage to ground: There should be battery voltage.	Blown No. 15 (20 A) fuse in the passenger's under-dash fuse/relay box Faulty passenger's multiplex control unit Faulty power window relay Poor ground (G651) An open in the wire
A12	BLK	Under all conditions	Check for voltage to ground: There should be less than 1 V.	Poor ground (G401, G601) An open in the wire
B1	BLK	Under all conditions	Check for voltage to ground: There should be less than 1 V.	Poor ground (G401, G601) An open in the wire
A20	WHT/RED	Under all conditions	Check for continuity between the A20 and B2 terminals: There should be continuity.	An open in the wire
B2	WHT/RED	Under all conditions		An open in the wire

If all the input tests prove OK, one of the control units must be faulty. Substitute a known-good control unit for the one that is most likely at fault using the chart below, then check the system. If the system works properly, the original control unit is faulty; replace it. If there is still a malfunction, substitute a known-good control unit for the next most likely unit to be at fault, and recheck. If the system works properly, the original unit is faulty; replace it.

CONTROL UNIT INPUT TEST (DOOR UNIT)

Affected window	Most likely control unit
Driver's window	Door multiplex control unit or power window control unit
Front passenger's window from power window master switch	Passenger's multiplex control unit
Right rear window from power window master switch	Passenger's multiplex control unit
Left rear window from power window master switch	Driver's multiplex control unit