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MICU Input Test

NOTE:
  • Before testing, troubleshoot the multiplex integrated control unit first, using B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).
  • Before testing, check the No. 1 (15 A), No. 10 (7.5 A), No. 14 (7.5 A), No. 20 (15 A) and No. 22 (7.5 A) fuses in the under-dash fuse/relay box.
  1. Turn the ignition switch to LOCK (0).
  2. Remove the fuse access panel (see FUSE ACCESS PANEL REMOVAL/INSTALLATION ), and remove the driver's dashboard lower cover (see FUSE ACCESS PANEL REMOVAL/INSTALLATION ).
  3. Disconnect under-dash fuse/relay box connectors A, B, K, M, N, and Q.
    NOTE: All connector views are shown from wire side of female terminals.
    Fig 1: Identifying Under-Dash Fuse/Relay Box Connectors A, B, K, M, N, And Q Terminals
    G08094550Courtesy of AMERICAN HONDA MOTOR CO., INC.
  4. Inspect the connector and socket terminals to make 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.
  5. With the connectors still disconnected, do the following input tests:
    • 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
    A25 RED VSA modulator-control unit 47P connector disconnected Check for continuity between terminal A25 and VSA modulator-control unit 47P connector terminal No. 10: There should be continuity. An open in the K-LINE wire
    B27 RED EPS control unit connector C (16P) disconnected Check for continuity between terminal B27 and EPS control unit connector C (16P) terminal No. 16: There should be continuity. An open in the K-LINE wire
    Q2 BLU Under all conditions Check for continuity between terminal Q2 and data link connector (DLC) (16P) terminal No. 7: There should be continuity. An open in the K-LINE wire
    Q2 BLU Immobilizer-keyless control unit 7P connector disconnected Check for continuity between terminal Q2 and immobilizer-keyless control unit 7P connector terminal No. 5: There should be continuity. An open in the K-LINE wire
    Q2(1) BLU Audio-Navigation unit connector A (24P) disconnected Check for continuity between terminal Q2 and audio-navigation unit connector A (24P) terminal No. 3: There should be continuity. An open in the K-LINE wire
    Q2(2) BLU Audio unit connector A (24P (17P(3))) disconnected Check for continuity between terminal Q2 and audio unit connector A (24P(17P(3))) terminal No. 3 (No. 6(3)): There should be continuity. An open in the K-LINE wire
    Q2(5) BLU TPMS control unit 20P connector disconnected Check for continuity between terminal 0.2 and TPMS control unit 20P connector terminal No. 7: There should be continuity. An open in the K-LINE wire
    Q2 BLU SRS unit connector A (39P) disconnected Check for continuity between terminal Q2 and SRS unit connector A (39P) terminal No. 18: There should be continuity. An open in the K-LINE wire
    Q3 GRN Immobilizer-keyless control unit 7P connector disconnected Check for continuity between terminal Q3 and immobilizer-keyless control unit 7P connector terminal No. 4: There should be continuity. An open in the B-CAN wire
    Q3 GRN Gauge control module 32P connector disconnected Check for continuity between terminal Q3 and gauge control module 32P connector terminal No. 17: There should be continuity. An open in the B-CAN wire
    Q3 GRN Climate control unit 36P connector disconnected Check for continuity between terminal Q3 and climate control unit 36P connector terminal No. 6: There should be continuity. An open in the B-CAN wire
    Q3(4) GRN HandsFreeLink control unit 28P connector disconnected Check for continuity between terminal Q3 and HandsFreeLink control unit 28P connector terminal No. 18: There should be continuity. An open in the B-CAN wire
    A25 RED Disconnect VSA modulator-control unit 47P connector Check for continuity to ground: There should be no continuity. A short to ground in the K-LINE wire
    B27 RED Disconnect EPS control unit connector C(16P) Check for continuity to ground: There should be no continuity. A short to ground in the K-LINE wire
    Q2 BLU Disconnect these connectors:
    • Immobilizer-keyless control unit 7P connector
    • TPMS control unit 20P connector(5)
    • Audio-Navigation unit connector A (24P)(1)
    • Audio unit connector A (24P)(2)
    • Audio unit connector A (17P)(2)(3)
    • SRS unit connector A (39P)
    Check for continuity to ground: There should be no continuity. A short to ground in the K-LINE wire
    Q3 GRN Disconnect these connectors:
    • Immobilizer-keyless control unit 7P connector
    • Gauge control module 32P connector
    • Climate control unit 36P connector
    • HandsFreeLink control unit 28P connector(4)
    Check for continuity to ground: There should be no continuity. A short to ground in the B-CAN wire
    (1) With navigation
    (2) Without navigation
    (3) DX model
    (4) Without navigation, with HandsFreeLink
    (5) With TPMS
  6. Reconnect the connectors to the under-dash fuse/relay box, and do the following input tests:
    • 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
    N2 BLK In all ignition switch positions Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G501)
    • An open or high resistance in the wire
    K10 BLK In all ignition switch positions Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground (G502)
    • An open or high resistance in the wire
    Q9 BLK In all ignition switch positions Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G501)
    • An open or high resistance in the wire
    M16 BLK In all ignition switch positions Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G502)
    • An open or high resistance in the wire
    N1 PNK Under all conditions Measure the voltage to ground: There should be battery voltage.
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    M18 PUR Ignition switch ACCESSORY (I) Measure the voltage to ground: There should be battery voltage.
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    K8 RED Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage.
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    Q8 LT BLU Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage.
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    Q14 RED Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage.
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
  7. 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.