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Home >> Acura >> 2003 >> MDX Base >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Keyless/Power Door Locks/Security System >> Control Unit Input Test >> Door Unit
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Door Unit

  1. Remove the door multiplex control unit, and disconnect its connector.
  2. Inspect the connector and socket terminals to be sure they are 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: Inspecting Connector And Socket Terminals
      G03642365Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. Reconnect the connector to the door multiplex control unit, turn the ignition switch ON (II) to keep the system awake, perform these input tests at the connector.
    • 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)

      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
      • 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)
      • An open in the wire
      A6 BLU/WHT Driver's door key cylinder switch in LOCK Check for voltage to ground:
      There should be less than 1 V.
      • Faulty driver's door key cylinder switch
      • Poor ground (G401)
      • An open in the wire
      • Short to ground
      Driver's door key cylinder switch in the neutral position Check for voltage to ground:
      There should be 5 V or more.
      Driver's door key cylinder switch in UNLOCK Check for voltage to ground:
      There should be 5 V or more.
      A16 BLU Driver's door key cylinder switch in UNLOCK Check for voltage to ground:
      There should be less than 1 V.
      • Faulty driver's door key cylinder switch
      • Poor ground (G401)
      • An open in the wire
      • Short to ground
      Driver's door key cylinder switch in the neutral position Check for voltage to ground:
      There should be 5 V or more.
      Driver's door key cylinder switch in LOCK Check for voltage to ground:
      There should be 5 V or more.
      A7 PNK Driver's door lock knob locked Check for voltage to ground:
      There should be less than 1 V.
      • Faulty driver's door lock actuator
      • Poor ground (G401)
      • An open in the wire
      Driver's door lock knob unlocked Check for voltage to ground:
      There should be 5 V or more.
      • Faulty driver's door lock actuator
      • Short to ground in the wire
      A17 BLK/RED Driver's door lock knob unlocked Check for voltage to ground:
      There should be less than 1 V.
      • Faulty driver's door lock actuator
      • Poor ground (G401)
      • An open in the wire
      Driver's door lock knob locked Check for voltage to ground:
      There should be 5 V or more.
      • Faulty driver's door lock actuator
      • Short to ground in the wire
      A8 BLK/WHT Driver's door lock switch in LOCK Check for voltage to ground:
      There should be less than 1 V.
      • Faulty driver's door lock switch
      • Poor ground (G401)
      • An open in the wire
      Driver's door lock switch in the neutral position Check for voltage to ground:
      There should be 5 V or more.
      • Faulty driver's door lock switch
      • Short to ground in the wire
      A18 GRN/RED Driver's door lock switch in UNLOCK Check for voltage to ground:
      There should be less than 1 V.
      • Faulty driver's door lock switch
      • Poor ground (G401)
      • An open in the wire
      Driver's door lock switch in the neutral position Check for voltage to ground:
      There should be 5 V or more.
      • Faulty driver's door lock switch
      • Short to ground in the wire
  4. 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, then recheck 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.
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