Headlight Auto Leveling Control Unit Input Test
With HID
  1. Disconnect the 16P connector (A) from the headlight auto leveling 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. With the connector still disconnected, make these input tests at the connector.
    • If any test indicated a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, go to Step 5 .
    Cavity
    Wire
    Test condition
    Test: Desired result
    Possible cause if result is not obtained
    1
    WHT
    Ignition switch ON (II)
    Check for voltage to ground: There should be battery voltage.
    • Blown No. 1 (7.5 A) fuse in the under-dash fuse/relay box
    • An open in the wire
    9
    BLK
    Under all conditions
    Check for continuity to ground: There should be continuity.
    • Poor ground (G503)
    • An open in the wire
    15
    BLU
    Ignition switch ON (II), raise the front of the vehicle, and rotate one wheel slowly while holding the other wheel
    Check for voltage between the No. 15 (+) and No. 9 (−) terminals: There should be 0−5 V or more 0−5 V or more repeatedly.
    • Faulty ECM
    • An open in the wire
    8
    RED
    Under all conditions
    Check for continuity between the No. 8 terminal and the No. 6 terminal of the combination light switch 12P connector: There should be continuity.
    • Combination light switch
    • An open in the wire
    16
    BRN
    Under all conditions
    Check for continuity between the No. 16 terminal and the No. 10 terminal of the combination light switch 12P connector: There should be continuity.
    • Combination light switch
    • An open in the wire

  1. Reconnect the connector to the headlight auto leveling control unit, and make these input tests at the connector.
    • If any test indicated a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, the headlight auto leveling control unit must be faulty, replace it, then go to Step 6 .
    Cavity
    Wire
    Test condition
    Test: Desired result
    Possible cause if result is not obtained
    3
    LT BLU
    Under all conditions
    Check for continuity to ground: There should be continuity.
    • Poor ground (G503)
    • An open in the wire
    12
    LT BLU
    4
    LT GRN
    2
    YEL
    Ignition switch ON (II), headlight switch ON
    Check for voltage between the No. 2 (+) and No. 3 (−) terminals: There should be battery voltage.
    • Faulty headlight leveling motors
    • An open in the wire
    3
    LT BLU
    11
    PNK
    Ignition switch ON (II), headlight switch ON
    Check for voltage between the No. 11 (+) and No. 3 (−) terminals: There should be between about 2 V and battery voltage.
    • Faulty headlights leveling motors
    • An open in the wire
    3
    LT BLU
    13
    GRY
    Under all conditions
    Check for voltage between the No. 13 and the No. 12 terminals : There should be about 5 V.
    • Faulty front headlight leveling sensor
    • An open in the wire
    6
    WHT
    Check for voltage between the No. 6 and the No. 12 terminals : There should be about 0.5−4.5 V.
    12
    LT BLU
    5
    RED
    Under all conditions
    Check for voltage between the No. 5 and the No. 4 terminals : There should be about 5 V.
    • Faulty rear headlight leveling sensor
    • An open in the wire
    7
    PUR
    Check for voltage between the No. 7 and the No. 4 terminals : There should be about 0.5−4.5 V.
    4
    LT GRN