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MICS (MICU) Input Test

  1. Turn the ignition switch to LOCK (0).
  1. Disconnect under-dash fuse/relay box connectors A, B, G, K, M, N, P, and Q.
    NOTE: All connector views are shown from 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 5 .
  1. With the connectors still disconnected, make these input tests at the connectors.
    • 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
    N2
    BLK
    Under all conditions
    Check for continuity to ground: There should be continuity.
    • Poor ground (G501)
    • An open in the wire
    K10
    BLK
    Under all conditions
    Check for continuity to ground: There should be continuity.
    • Poor ground (G502)
    • An open in the wire
    Q9
    BLK
    Under all conditions
    Check for continuity to ground: There should be continuity.
    • Poor ground (G502)
    • An open in the wire
    M16
    BLK
    Under all conditions
    Check for continuity to ground: There should be continuity.
    • Poor ground (G501)
    • An open in the wire
    Q2
    BLU
    Under all conditions
    Check for continuity between the Q2 terminal and the data link connector (16P) connector No. 7 terminal: There should be continuity.
    An open in the wire
    Q2
    BLU
    Immobilizer-keyless control unit 7P connector disconnected
    Check for continuity between the Q2 terminal and the immobilizer-keyless control unit 7P connector No. 5 terminal: There should be continuity.
    An open in the wire
    Q2
    BLU
    Audio unit connector A (24P) disconnected
    Check for continuity between the Q2 terminal and audio unit connector A (24P) No. 3 terminal: There should be continuity.
    An open in the wire
    Q2
    BLU
    SRS unit connector A (39P) disconnected
    Check for continuity between the Q2 terminal and SRS unit connector A (39P) No. 18 terminal: There should be continuity.
    An open in the wire
    Q2
    BLU
    ABS modulator-control unit 25P connector disconnected
    Check for continuity between the Q2 terminal and the ABS modulator-control unit 25P connector No. 10 terminal: There should be continuity.
    An open in the wire
    Q2
    BLU
    VSA modulator-control unit 36P connector disconnected
    Check for continuity between the Q2 terminal and the VSA modulator-control unit 36P connector No. 3 terminal: There should be continuity.
    An open in the wire
    Q2
    BLU
    EPS control unit connector C (16P) disconnected
    Check for continuity between the Q2 terminal and EPS control unit connector C (16P) No. 16 terminal: There should be continuity.
    An open in the wire
    Q3
    LT GRN
    Immobilizer-keyless control unit 7P connector disconnected
    Check for continuity between the Q3 terminal and the immobilizer-keyless control unit 7P connector No. 4 terminal: There should be continuity.
    An open in the wire
    Q3
    LT GRN
    Gauge control module 32P connector disconnected
    Check for continuity between the Q3 terminal and the gauge control module 32P connector No. 18 terminal: There should be continuity.
    An open in the wire
    Q3
    LT GRN
    Climate control unit 36P connector disconnected
    Check for continuity between the Q3 terminal and the climate control unit 36P connector No. 6 terminal: There should be continuity.
    An open in the wire
    Q3
    LT GRN
    Hands free telephone control unit 28P connector disconnected
    Check for continuity between the Q3 terminal and the hands free telephone control unit 28P connector No. 18 terminal:
    There should be continuity.
    An open in the wire
    Q3
    LT GRN
    Headlight leveling control unit 16P connector disconnected
    Check for continuity between the Q3 terminal and the headlight leveling control unit 16P connector No. 16 terminal:
    There should be continuity.
    An open in the wire
    Q3
    LT GRN
    Automatic lighting/rain sensor 5P connector disconnected
    Check for continuity between the Q3 terminal and the automatic lighting/rain sensor 5P connector No. 5 terminal:
    There should be continuity.
    An open in the wire
    Q2
    BLU
    Disconnect these connectors:
    • Immobilizer-keyless control unit 7P connector
    • Audio unit connector A (24P)
    • SRS unit connector A (39P)
    • ABS modulator control unit 25P connector (Without VSA)
    • VSA modulator control unit 36P connector (With VSA)
    • EPS control unit connector C (16P)
    Check for continuity to ground:
    There should be no continuity.
    A short to ground in the wire
    Q3
    LT GRN
    Disconnect these connectors:
    • Immobilizer-keyless control unit 7P connector
    • Gauge control module 32P connector
    • Climate control unit 36P connector (With climate control)
    • Hands free telephone control unit 28P connector (With hands free telephone system)
    • Headlight leveling control unit 16P connector (With HID)
    • Automatic lighting/rain sensor 5P connector (With automatic lighting/automatic wiper system)
    Check for continuity to ground:
    There should be no continuity.
    A short to ground in the wire


  1. Reconnect the connectors to the under-dash fuse/relay box, and 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 7 .
    Cavity
    Wire
    Test condition
    Test: Desired result
    Possible cause if desired result is not obtained
    N1
    PNK
    Under all conditions
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 1 (10 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    M18
    PUR
    Ignition switch ACC (I)
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 14 (7.5 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    K8
    RED
    Ignition switch ON (II)
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 20 (15 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    Q8
    LT BLU
    Ignition switch ON (II)
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 22 (7.5 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    P2
    PUR
    Ignition switch ON (II)
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 6 (10 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    A32
    PUR
    Ignition switch ON (II)
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 11 (7.5 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    B11
    PUR
    Ignition switch ON (II)
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 11 (7.5 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    Q14
    BRN
    Ignition switch ON (II)
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 10 (7.5 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    A31
    LT GRN
    Ignition switch ON (II)
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 5 (10 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    G5
    LT BLU
    Under all conditions
    Measure the voltage to ground: There should be battery voltage.
    • Blown No. 1 (10 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire

  1. If multiple failures are found on more than one control unit, replace the under-dash fuse/relay box (includes the MICU). If input failures are related to a particular control unit, replace the control unit.