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Passenger's Multiplex Control Unit

WARNING: This page is about a different car, the 2006 Acura MDX, 2005 Acura MDX, 2004 Acura MDX, and 2003 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.
  1. Remove the passenger's multiplex control unit from the passenger's under-dash fuse/relay box, and disconnect its connector.
  2. 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
      G03642197Courtesy of AMERICAN HONDA MOTOR CO., INC.
      Fig 2: Identifying Passenger's Under-Dash Fuse/Relay Box Connector (C)
      G03642198Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. 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 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
  4. 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
      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
      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
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