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MICU Input Test

NOTE:
  • Before testing, check the No. B5 (10 A), No. B16 (10 A), No. B21 (15 A), No. B56 (30 A), and No. B60 (50 A) fuses in the under-dash fuse/relay box.
  • If there is a malfunction of the rear window wiper operation, and no DTCs are detected, check the rear window wiper motor and an open in the ground circuit of the rear window wiper (see step  10 ).
  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, N, Q, R, Y, and AD.
    NOTE: All connector views are wire side of female terminals.
    Fig 1: Identifying Under-Dash Fuse/Relay Box Connectors A, B, D, N, Q, R, Y, And AD
    G06954078Courtesy 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
      AD1 YEL Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage.
      • Blown No. B60 (50 A) fuse in the under-dash fuse/relay box
      • Faulty ignition switch
      • An open or high resistance in the wire
      A23 GRN Under all conditions Connect terminal A23 to battery power: The windshield wiper motor should run at high speed.
      • Poor ground (G401) or an open in the ground wire
      • Faulty windshield wiper motor
      • An open or high resistance in the wire
      A19 BLU Under all conditions Connect terminal A19 to battery power: The windshield wiper motor should run at low speed.
      A26 WHT Under all conditions Connect terminal A26 to battery power and terminal A25 to body ground: The windshield/rear window washer motor should run.
      • Faulty windshield/rear window washer motor
      • An open or high resistance in the wire
      A25 GRN Under all conditions Connect terminal A25 to battery power and terminal A26 to body ground: The windshield/rear window washer motor should run.
      • Faulty windshield/rear window washer motor
      • An open or high resistance in the wire
      B9 LT GRN The motor stops at auto-stop position. Check for continuity to ground: There should be no continuity.
      • Faulty windshield wiper motor
      • A short to ground in the wire
      Connect the terminal A19 to battery power momentarily, and stop the motor operation before the motor reaches the auto-stop position. Check for continuity to ground: There should be continuity.
      • Faulty windshield wiper motor
      • Poor ground (G401) or an open in the ground wire
      • An open or high resistance in the wire
      Y2
      .
      Y4      		 PNK
      .
      BLK      		 Windshield wiper/washer switch (intermittent dwell timer) turned Check resistance between the terminals: The resistance should vary between 0 to 1 kΩ.
      • Faulty windshield wiper/washer switch
      • An open or high resistance in the wire
      D23
      .
      D10      		 PUR
      .
      BRN      		 Connect battery power to terminal D23, then connect terminal D10 to body ground momentarily. Check rear window wiper motor operation: The rear window wiper motor should run.
      • Faulty rear window wiper motor
      • Poor ground (G801) or an open in the ground wire
      • An open or high resistance in the wire
      D18
      .
      B3(1)      		 LT GRN
      .
      GRY      		 Transmission shifted to reverse Check for continuity between the terminals D18 and B3: There should be continuity.
      • Faulty back-up light switch
      • An open or high resistance in the wire
      Transmission shifted to any position other than reverse Check for continuity between the terminals D18 and B3: There should be no continuity. Faulty back-up light switch
      (1) M/T models
  6. Reconnect the connectors to the under-dash fuse/relay box, turn the ignition switch to ON (II), 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
        B17(1) PNK Transmission range switch in R Measure the voltage to ground: There should be less than 0.2 V.
        • Poor ground (G101) or an open in the ground wire
        • Faulty or improperly installed transmission range switch
        • An open or high resistance in the wire
        Transmission range switch in any position other than R Measure the voltage to ground: There should be at least 5 V.
        • Faulty or improperly installed transmission range switch
        • A short to ground in the wire
        Q8
        .
        Y4        		 RED
        .
        BLK        		 Windshield wiper/washer switch (LO or HI) ON Measure the voltage between terminals Q8 and Y4: There should be less than 0.2 V.
        • Faulty windshield wiper/washer switch
        • Poor ground (G501, G502) or an open in the ground wire
        • An open or high resistance in the wire
        Windshield wiper/washer switch OFF Measure the voltage between terminals Q8 and Y4: There should be at least 5 V. Faulty windshield wiper/washer switch
        Q7
        .
        Y4        		 ORN
        .
        BLK        		 Windshield wiper/washer switch (INT or LO) ON Measure the voltage between terminals Q7 and Y4: There should be less than 0.2 V.
        • Faulty windshield wiper/washer switch
        • Poor ground (G501, G502) or an open in the ground wire
        • An open or high resistance in the wire
        Windshield wiper/washer switch OFF Measure the voltage between terminals Q7 and Y4: There should be at least 5 V. Faulty windshield wiper/washer switch
        Q6
        .
        Y4        		 GRN
        .
        BLK        		 Windshield wiper/washer switch (MIST) ON Measure the voltage between terminals Q6 and Y4: There should be less than 0.2 V.
        • Faulty windshield wiper/washer switch
        • Poor ground(G501, G502) or an open in the ground wire
        • An open or high resistance in the wire
        Windshield wiper/washer switch OFF Measure the voltage between terminals Q6 and Y4: There should be at least 5 V. Faulty windshield wiper/washer switch
        Q5
        .
        Y4        		 PUR
        .
        BLK        		 Washer switch ON Measure the voltage between terminals Q5 and Y4: There should be less than 0.2 V.
        • Faulty windshield wiper/washer switch
        • Poor ground (G501, G502) or an open in the ground wire
        • An open or high resistance in the wire
        Washer switch OFF Measure the voltage between terminals Q5 and Y4: There should be at least 5 V. Faulty windshield wiper/washer switch
        Q4
        .
        Y4        		 YEL
        .
        BLK        		 Rear window wiper/washer switch (RRWIPER)ON Measure the voltage between terminals Q4 and Y4: There should be less than 0.2 V.
        • Faulty rear window wiper/washer switch
        • Poor ground (G501, G502) or an open in the ground wire
        • An open or high resistance in the wire
        Rear window wiper/washer switch OFF Measure the voltage between terminals Q4 and Y4: There should be at least 5 V. Faulty rear window wiper/washer switch
        Q3
        .
        Y4        		 BLU
        .
        BLK        		 Rear window wiper/washer switch (RRWASH) ON Measure the voltage between terminals Q3 and Y4: There should be less than 0.2 V.
        • Faulty rear window wiper/washer switch
        • Poor ground (G501, G502) or an open in the ground wire
        • An open or high resistance in the wire
        Rear window wiper/washer switch OFF Measure the voltage between terminals Q3 and Y4: There should be at least 5 V. Faulty rear window wiper/washer switch
        (1) CVT models
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