Passenger's Multiplex Control Unit

Remove the passenger's multiplex control unit from the passenger's under-dash fuse/relay box, and disconnect its connector.
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 Passenger's Under-Dash Fuse/Relay Box Socket
  Courtesy of AMERICAN HONDA MOTOR CO., INC.
  
  Fig 2: Identifying Passenger's Under-Dash Fuse/Relay Box Connector (C)
  Courtesy of AMERICAN HONDA MOTOR CO., INC.

With the passenger's multiplex control unit still disconnected, make these input tests at the connector and passenger's under-dash fuse/relay box socket.

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.

TEST CONDITION AND TEST DESIRED RESULT CHART

Cavity	Wire	Test condition	Test: Desired result	Possible cause if result is not obtained
A22	Fuse/relay box socket	Ignition switch ON (II)	Check for voltage to ground: There should be battery voltage.	Blown No. 9 (10 A) fuse in the driver's under-dash fuse/relay box Faulty passenger's under-dash fuse/relay box An open in the wire
A21	Fuse/relay box socket	Interior light switch in the middle position	Attach to ground: Ceiling lights should come on.	Blown No. 11 (10 A) fuse in the passenger's under-dash fuse/relay box Blown No. 54 (40 A) fuse in the under-hood fuse/relay box Faulty passenger's under-dash fuse/relay box Faulty ceiling light Faulty interior lights switch An open in the wire

Reconnect the passenger's multiplex control unit to the passenger's under-dash fuse/relay box, turn the ignition switch ON (II) to keep the system awake, and perform the following input tests at the appropriate connectors on the back of the passenger's under-dash fuse/relay box.

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

If the input test proves OK, go to step 1 in DOOR MULTIPLEX CONTROL UNIT .

TEST CONDITION AND TEST DESIRED RESULT CHART

Cavity	Wire	Test condition	Test: Desired result	Possible cause if result is not obtained
C16	GRN	Passenger's door open	Check for voltage to ground: There should be less than 1 V.	Faulty passenger's door switch An open in the wire
C16	GRN	Passenger's door closed	Check for voltage to ground: There should be 5 V or more.	Faulty passenger's door switch A short to ground in the wire
C14	GRN/WHT	Right rear door open	Check for voltage to ground: There should be less than 1 V.	Faulty right rear door switch An open in the wire
C14	GRN/WHT	Right rear door closed	Check for voltage to ground: There should be 5 V or more.	Faulty right rear door switch A short to ground in the wire