Headlight Leveling Control Unit Input Test/Replacement
NOTE: Before testing, make sure that there is no DTCs and combination light switch circuit is OK.
  1. Turn the ignition switch to LOCK (0).
  1. Remove the driver's dashboard undercover, then remove the dashboard lower cover.
  1. Remove the bolt from the headlight leveling control unit bracket, then disconnect the 16P connector (A) from the headlight 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 are OK, go to Step 5 .
  1. With the connector still disconnected, make 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 6 .
    Cavity
    Wire
    Test condition
    Test: Desired result
    Possible cause if desired result is not obtained
    9
    BLK
    Under all conditions
    Check for continuity to ground: There should be continuity.
    • Poor ground (G503) [G251]
    • An open in the wire
    1
    BLU
    Ignition switch ON (II)
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 6 (7.5 A) fuse in the driver's under-dash fuse/relay box
    • An open in the wire

    [ ]:
    RHD model

  1. Reconnect the connector, turn the ignition switch to ON (II), and make these input tests at the connector.
    • If any tests indicates a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, replace the headlight leveling control unit.
    NOTE: After replacing the control unit, do the headlight initial position learning procedure.
    Cavity
    Wire
    Test condition
    Test: Desired result
    Possible cause if desired result is not obtained
    3
    WHT
    Under all conditions
    Measure the voltage to ground: There should be less than 0.5 V.
    • Poor ground (G503) [G251]
    • An open in the wire
    4
    LT BLU
    Under all conditions
    Measure the voltage to ground: There should be less than 0.5 V.
    • Poor ground (G503) [G251]
    • An open in the wire
    2
    YEL
    Ignition switch ON (II), headlight switch ON
    Measure the voltage between the No. 2 and No. 3 terminals: There should be battery voltage.
    • Faulty headlight leveling motor
    • An open in the wire
    3
    WHT
    11
    ORN
    Ignition switch ON (II), headlight switch ON
    Measure the voltage between the No. 11 and No. 3 terminals: There should be about 2 to 12 V.
    • Faulty headlight leveling motor
    • An open in the wire
    3
    PNK
    4
    LT BLU
    Ignition switch ON (II)
    • Measure the voltage between the No. 4 and No. 13 terminals: There should be about 5 V.
    • Measure the voltage between the No. 4 and No. 6 terminals: There should be about 0.5 to 4.5 V.
    • Faulty front suspension stroke sensor
    • An open in the wire
    6
    GRN
    13
    GRY
    4
    LT BLU
    Ignition switch ON (II)
    • Measure the voltage between the No. 4 and No. 13 terminals: There should be about 5 V.
    • Measure the voltage between the No. 4 and No. 7 terminals: There should be about 0.5 to 4.5 V.
    • Faulty rear suspension stroke sensor
    • An open in the wire
    7
    LT GRN
    13
    GRY

    [ ]:
    RHD model