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MICU Input Test

NOTE:
  • Before testing, make sure the turn signal/hazard warning lights work properly.
  • Before testing, check the No. B1 (15 A), No. B20(15 A), No. B22 (7.5 A), No. B23 (10A), No. B24 (10A), No. B27(20A), No. B35 (7.5 A), No. B36 (10 A), No. B45 (20 A), No. B49 (7.5 A), and No. B60 (50 A) fuses in the under-dash fuse/relay box.
  • There are two circuits that each have a pair of fuses (No. 35 and No. 49 fuses. No. 36 and No. 45 fuses). If one fuse is blown, make sure to check the other fuse in the same circuit. If necessary, replace the blown fuse(s).
  1. Turn the ignition switch to LOCK (0).
  2. Remove the fuse lid panel (see FUSE LID PANEL REMOVAL/INSTALLATION ), and remove the driver's dashboard lower cover (see FUSE LID PANEL REMOVAL/INSTALLATION ).
  3. Disconnect under-dash fuse/relay box connectors A, B, D, F, G, N, Q, R, Y, AA, and AD.
    NOTE: All connector views are wire side of female terminals.
    Fig 1: Identifying Under-Dash Fuse/Relay Box Connectors A, B, D, F, G, N, Q, R, Y, AA, And AD
    G06953911Courtesy of AMERICAN HONDA MOTOR CO., INC.
  4. 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.
  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.
      MICU INPUT TEST REFERENCE

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      N6 BLU Connect the battery positive terminal to terminal N6, and connect terminal AA6 and G1 to body ground Check actuator operation: The driver's door lock actuator should unlock.
      • Faulty driver's door lock actuator
      • An open or high resistance in the wire
      • Faulty driver's door unlock relay
      • Poor ground(G501) or an open in the ground wire
      AA6 RED
      G1 PUR
      G1 PUR Connect the battery positive terminal to terminal G1 Check actuator operation: The driver's door lock actuator should lock.
      • Faulty driver's door lock actuator
      • An open or high resistance in the wire
      • Faulty driver's door unlock relay
      • Poor ground (G501) or an open in the ground wire
      N10 GRN Connect the battery positive terminal to terminal N10 (N9), and connect terminal N9 (N10) to body ground Check actuator operation: The left rear door lock actuator should lock (or unlock).
      • Faulty passenger's door lock actuator
      • An open or high resistance in the wire
      N9 PNK
      N6 BLU Connect the battery positive terminal to terminal N6, and connect terminal Q27 to body ground Check actuator operation: The hatch release actuator should work.
      • Faulty hatch release actuator
      • An open or high resistance in the wire
      • Faulty hatch release actuator relay
      • Poor ground (G801) or an open in the ground wire
      Q27 YEL
      A20 BLU Under all conditions Connect terminal A20 and terminal B32 with a jumper wire: The horn should sound.
      • Faulty horn
      • An open or high resistance in the wire
      • Poor ground
  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, the MICU must be faulty; replace the under-dash fuse/relay box:
      • USA models (see REMOVAL AND INSTALLATION )
      • Canada models (see CANADA MODELS )
        MICU INPUT TEST REFERENCE

        Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
        R2 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
        N5 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
        Y16 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
        Q2 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
        Q29 GRN Under all conditions Measure the voltage to ground: There should be less than 0.2 V/3
        • Poor ground(G503) or an open in the ground wire
        • Faulty audio-navigation unit(1) or audio unit(2)
        • An open or high resistance in the wire
        D1 PNK Hatch outer handle switch pressed Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground(G801) or an open in the ground wire
        • An open or high resistance in the wire
        • Faulty hatch outer handle switch
        B32 WHT Under all conditions Measure the voltage to ground: There should be battery voltage.
        • Blown No. A3 (20 A) fuse in the battery terminal fuse box
        • An open or high resistance in the wire
        AD1 YEL Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage.
        • Blown No. A1 (100 A) fuse in the battery terminal fuse box
        • Blown No. B60(IGN) (50A) fuse in the under-dash fuse/relay box
        • Faulty ignition switch
        • An open or high resistance in the wire
        D26 PNK Driver's door open Measure the voltage to ground: There should be less than 0.2 V.
        • Faulty driver's door switch
        • Faulty driver's door switch ground
        • An open or high resistance in the wire
        Driver's door closed Measure the voltage to ground: There should be at least 5 V.
        • Faulty driver's door switch
        • A short to ground in the wire
        D27 BRN Passenger's door open Measure the voltage to ground: There should be less than 0.2 V.
        • Faulty passenger's door switch
        • Faulty passenger's door switch ground
        • An open or high resistance in the wire
        Passenger's door closed Measure the voltage to ground: There should be at least 5 V.
        • Faulty passenger's door switch
        • A short to ground in the wire
        D17 ORN Hatch open Measure the voltage to ground: There should be less than 0.2 V.
        • Faulty hatch latch switch
        • Poor ground(G801)or an open in the ground wire
        • An open or high resistance in the wire
        Hatch closed Measure the voltage to ground: There should be at least 5 V.
        • Faulty hatch latch switch
        • A short to ground in the wire
        A28 PUR Hood open Measure the voltage to ground: There should be less than 0.2 V.
        • Faulty security hood switch
        • Poor ground(G403) or an open in the ground wire
        • An open or high resistance in the wire
        Hood closed Measure the voltage to ground: There should be at least 5 V.
        • Faulty security hood switch
        • A short to ground in the wire
        F10 YEL Driver's door lock knob switch in LOCK Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground(G501)or an open in the ground wire
        • Faulty driver's door lock knob switch
        • An open or high resistance in the wire
        Driver's door lock knob switch in UNLOCK Measure the voltage to ground: There should be at least 5 V.
        • Faulty driver's door lock knob switch
        • A short to ground in the wire
        F5 LT BLU Driver's door lock knob switch in UNLOCK Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground (G501) or an open in the ground wire
        • Faulty driver's door lock knob switch
        • An open or high resistance in the wire
        Driver's door lock knob switch in LOCK Measure the voltage to ground: There should be at least 5 V.
        • Faulty driver's door lock knob switch
        • A short to ground in the wire
        Q28 PUR Passenger's door lock knob switch in UNLOCK Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground(G502) or an open in the ground wire
        • Faulty passenger's door lock knob switch
        • An open or high resistance in the wire
        Passenger's door lock knob switch in LOCK Measure the voltage to ground: There should be at least 5 V.
        • Faulty passenger's door lock knob switch
        • A short to ground in the wire
        Q18 GRY Ignition key inserted into the ignition switch Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground (G502) or an open in the ground wire
        • Faulty ignition key switch
        • An open or high resistance in the wire
        Ignition switch in LOCK (0), and the ignition key removed from the ignition switch Measure the voltage to ground: There should be at least 5 V.
        • Faulty ignition key switch
        • A short to ground in the wire
        F4 PNK Driver's door key cylinder switch in LOCK Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground (G501) or an open in the ground wire
        • Faulty driver's door key cylinder switch
        • An open or high resistance in the wire
        Driver's door key cylinder switch in neutral or UNLOCK Measure the voltage to ground: There should be at least 5 V.
        • Faulty driver's door key cylinder switch
        • A short to ground in the wire
        F3 GRY Driver's door key cylinder switch in UNLOCK Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground (G501) or an open in the ground wire
        • Faulty driver's door key cylinder switch
        • An open or high resistance in the wire
        Driver's door key cylinder switch in neutral or LOCK Measure the voltage to ground: There should be at least 5 V.
        • Faulty driver's door key cylinder switch
        • A short to ground in the wire
        F11 GRN Driver's door lock switch in LOCK Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground (G501) or an open in the ground wire
        • Faulty door lock switch
        • An open or high resistance in the wire
        Driver's door lock switch in neutral or UNLOCK Measure the voltage to ground: There should be at least 5 V.
        • Faulty door lock switch
        • A short to ground in the wire
        F6 LT GRN Driver's door lock switch in UNLOCK Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground (G501) or an open in the ground wire
        • Faulty door lock switch
        • An open or high resistance in the wire
        Driver's door lock switch in neutral or LOCK Measure the voltage to ground: There should be at least 5 V.
        • Faulty door lock switch
        • A short to ground in the wire
        (1) With navigation
        (2) Without navigation

        *3: If the factory-installed audio unit or audio-navigation unit is removed from the vehicle, this voltage will be between 10-12V.
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