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Home >> Acura >> 2003 >> MDX Base >> Repair and Diagnosis >> Accessories & Equipment >> Interior/Illumination Lights >> Entry Lights Control System >> Control Unit Input Test >> Door Multiplex Control Unit
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Door Multiplex Control Unit

  1. Remove the driver's door panel and disconnect the 20P connector from the door multiplex control unit.
  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: Inspecting Connector And Socket Terminals
      G03642199Courtesy 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, and perform the input test at the connector.
    • If a test indicates a problem, find and correct the cause, then recheck the system.
    • If the input test proves 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
      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
  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.