Automatic Lighting Control Unit Input Test

  1. Disconnect the 14P connector (A) from the automatic lighting control unit (B).
  1. 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 .

  1. 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.
    Cavity
    Wire
    Test condition
    Test: Desired result
    Possible cause if result is not obtained
    7
    YEL
    Ignition switch ON (II) or START (III)
    Check for voltage to ground: There should be battery voltage.
    • Blown No. 7 (10 A) fuse in the driver's under-dash fuse/relay box
    • An open in the wire
    1
    WHT
    Ignition switch ON (II)
    • Blown No. 21 (7.5 A) fuse in the driver's under-dash fuse/relay box
    • An open in the wire
    4
    LT 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
    Check for continuity to ground: There should be continuity.
    • Poor ground (G506)
    • An open in the wire
    9
    11
    BLU
    Driver's door open *
    Check for voltage to ground: There should be 1 V or less.
    • Faulty driver's door switch
    • An open in the wire
    2
    WHT
    Combination light switch ON (Except ‘‘AUTO'')
    Check for continuity to ground: There should be continuity.
    • Faulty combination light switch
    • Poor ground (G501, G601)
    • An open in the wire

    *:
    Reconnect the 14P connector to the control unit

    NOTE: Before testing, connect a voltmeter and jumper wires as shown:
Cavity
Wire
Test condition
Test: Desired result
Possible cause if result is not obtained
6
RED
Cover the automatic lighting sensor *
Check for voltage between the No. 6 terminal and body ground: There should be 1 V or less.
  • Faulty automatic lighting sensor
  • An open in the wire
Shine light on the automatic lighting sensor
Check for voltage between the No. 6 terminal and body ground: There should be 5 V or more.
  • Faulty automatic lighting sensor
  • An open in the wire

*:
The automatic lighting sensor is located in the middle of dashdoard. Cut the light off completely with a dark cloth.