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Automatic Lighting Control Unit Input Test

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 driver's dashboard lower cover (see DRIVER'S DASHBOARD UNDER COVER REMOVAL/INSTALLATION ).
  2. Disconnect the 14P connector (A) from the automatic lighting control unit (B).
    Fig 1: Disconnecting 14P Connector From Automatic Lighting Control Unit
    G03642133Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. 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 4.
  4. Make these input tests at the connector.
    • If any test indicates a problem, find and correct the cause, then recheck the system.
    • If all input tests prove OK, the control unit must be faulty; replace it.
      AUTOMATIC LIGHTING CONTROL UNIT INPUT TEST (1 OF 2)

      Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained
      2 YEL Ignition switch ON (II) or START (III) (1) 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
      • An open in the wire
      3 ORN Ignition switch ON (II)(1)
      • Blown No. 4 (7.5 A) fuse in the driver's under-dash fuse/relay box
      • An open in the wire
      5 BUU/GRN Combination switch in the OFF, PARK, and AUTO positions Check for voltage to ground:
      There should be battery voltage.
      • Faulty headlight relay 1 or 2
      • An open in the wire
      8 BLK Under all conditions(1) Check for voltage to ground:
      There should be less than 1 V.
      • Poor ground (G401)
      • An open in the wire
      9
      10 WHT/YEL Under all conditions(1) 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
      12 GRN/ORN Driver's door open(1) Check for voltage to ground:
      There should be less than 1 V.
      • Faulty driver's door switch
      • An open in the wire
      13 WHT/BLK Combination light switch ON (Except "AUTO") Check for continuity to ground:
      There should be continuity.
      • Faulty combination light switch
      • Poor ground (G401)
      • An open in the wire
      14 RED/YEL Under all conditions Check for voltage to ground:
      There should be battery voltage.
      • Faulty taillight relay
      • An open in the wire
      • Blown No. 10 (15 A) fuse in the passenger's under-dash fuse/relay box
      (1) Reconnect the 14P connector to the control unit
      NOTE: Before testing, connect a voltmeter and jumper wires as shown in Fig 2 :
      Fig 2: Connecting Voltmeter And Jumper Wires
      G03642134Courtesy of AMERICAN HONDA MOTOR CO., INC.
      AUTOMATIC LIGHTING CONTROL UNIT INPUT TEST (2 OF 2)

      Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained
      4 BLU/BLK Cover the automatic lighting sensor(1) Check for voltage between the No. 4 terminal and body ground:
      There should be less than 1 V.
      • Faulty automatic lighting sensor
      • An open in the wire
      Shine light on the automatic lighting sensor Check for voltage between the No. 4 terminal and body ground:
      There should be 5 V or more.
      • Faulty automatic lighting sensor
      • An open in the wire
      (1) The automatic lighting sensor is located in the middle of dashboard. Cut the light off completely with a dark cloth.