Multiplex Integrated Control Unit Input Test

  1. Disconnect the under-dash fuse/relay box connectors D, E, H, I, J, K, N, P and X.
    NOTE: All connectors are wire side of female terminals.
  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 connectors still disconnected from the under-hood fuse/relay box, make these input tests at the connector(s).
    • 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 5 .
    Cavity
    Wire
    Test condition
    Test: Desired result
    Possible cause if result is not obtained
    H9
    BLK
    Under all conditions
    Check for continuity to ground: There should be continuity.
    • Poor ground (G601)
    • An open in the wire
    P1 *1 P14 *2
    BRN
    Under all conditions
    Check for continuity to ground:There should be continuity.
    • Poor ground (G502)
    • An open in the wire
    E9
    BLK
    Under all conditions
    Check for continuity to ground: There should be continuity.
    • Poor ground (G601)
    • An open in the wire
    D6·J9·X34
    YEL
    Ignition switch ON (II)
    Check for voltage to ground: There should be battery voltage.
    • Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box
    • An open in the wire
    K4
    GRN/WHT
    Under all conditions
    Check for voltage to ground: There should be battery voltage.
    • Blown No. 27 (20 A) fuse in the under-dash fuse/relay box
    • An open in the wire
    X35
    WHT
    Under all conditions
    Check for voltage to ground: There should be battery voltage.
    • Blown No. 7 (10 A) fuse in the under-dash fuse/relay box
    • An open in the wire
    N22
    LT BLU
    Under all conditions
    Check for continuity between terminal N22 and the climate control unit B (16P) connector terminal No. 14: There should be continuity.
    • An open in the wire
    Climate control unit B (16P) connector disconnected
    Check for continuity to ground: There should be no continuity.
    • Short to ground
    J4
    BRN/RED
    Under all conditions
    Check for continuity between terminal J4 and power window master switch 23P connector terminal No. 16: There should be continuity.
    • An open in the wire
    Power window master switch 23P connector disconnected
    Check for continuity to ground: There should be no continuity.
    • Short to ground
    D11
    BLU
    Under all conditions
    Check for continuity between terminal D11 and relay module J (10P) connector terminal No. 7: There should be continuity.
    • An open in the wire
    Relay module J (10P) connector disconnected
    Check for continuity to ground: There should be no continuity.
    • Short to ground
    X27
    LT GRN
    Under all conditions
    Check for continuity between terminal X27 and wiper/washer switch 8P connector terminal No. 4: There should be continuity.
    • An open in the wire
    Wiper/washer switch 8P connector disconnected
    Check for continuity to ground: There should be no continuity.
    • Short to ground
    N28
    WHT
    Under all conditions
    Check for continuity between terminal N28 and gauge assembly (30P) connector terminal No. 25: There should be continuity.
    • An open in the wire
    Gauge assembly B (30P) connector disconnected
    Check for continuity to ground: There should be no continuity.
    • Short to ground
    G1
    GRN/RED
    Under all conditions
    Check for continuity between terminal G1 and power tailgate control unit connector A (26P) terminal No. 21: There should be continuity.
    • An open in the wire

    *1:
    LHD type
    *2:
    RHD type

  1. Reconnect the connectors to the under-dash fuse/relay box, and make sure these input tests at the appropriate connectors on the under-dash fuse/relay box.
    • If any test indicates a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, the multiplex integrated contorl unit must be faulty, replace the under-dash fuse/relay box assembly.
    Cavity
    Wire
    Test condition
    Test: Desired result
    Possible cause if result is not obtained
    P7 *1 P8 *2
    ORN
    Under all conditions
    Attach to ground: The ignition key light should come on.
    • Blown No. 13 (20 A) fuse in the under-hood fuse/relay box
    • Blown LED
    • An open in the wire
    I4
    GRN/RED
    Ceiling light switch in the middle position, all doors closed
    Attach to ground: The ceiling light should come on.
    • Blown No. 6 (7.5 A) fuse in the under-dash fuse/relay box
    • Faulty ceiling light
    • An open in the wire

    *1:
    LHD type
    *2:
    RHD type