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Power Mirror Circuit Input Test: MICU

  1. Turn the ignition switch to LOCK (0).
  2. Remove the left side kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ).
  3. Disconnect under-dash fuse/relay box connector P (30P).
    Fig 1: Identifying Under-Dash Fuse/Relay Box Connector P (30P) Terminals
    G08053971Courtesy 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. Reconnect the connector 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 6.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    P9 WHT Power mirror switch in UP Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground (G501) or an open in the ground wire
    • Faulty power mirror switch
    • An open or high resistance in the wire
    Power mirror switch released Measure the voltage to ground: There should be at least 5 V.
    • Faulty power mirror switch
    • A short to ground in the wire
    P10 PNK Power mirror switch in DOWN Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground (G501) or an open in the ground wire
    • Faulty power mirror switch
    • An open or high resistance in the wire
    Power mirror switch released Measure the voltage to ground: There should be at least 5 V.
    • Faulty power mirror switch
    • A short to ground in the wire
    P25 GRN Power mirror switch in LEFT Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground (G501) or an open in the ground wire
    • Faulty power mirror switch
    • An open or high resistance in the wire
    Power mirror switch released Measure the voltage to ground: There should be at least 5 V.
    • Faulty power mirror switch
    • A short to ground in the wire
    P26 BLU Power mirror switch in RIGHT Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground (G501) or an open in the ground wire
    • Faulty power mirror switch
    • An open or high resistance in the wire
    Power mirror switch released Measure the voltage to ground: There should be at least 5 V.
    • Faulty power mirror switch
    • A short to ground in the wire
    P11 PUR Power mirror switch in L position Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground (G501) or an open in the ground wire
    • Faulty power mirror switch
    • An open or high resistance in the wire
    Power mirror switch released Measure the voltage to ground: There should be at least 5 V.
    • Faulty power mirror switch
    • A short to ground in the wire
    P22 GRY Power mirror switch in R position Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground (G501) or an open in the ground wire
    • Faulty power mirror switch
    • An open or high resistance in the wire
    Power mirror switch released Measure the voltage to ground: There should be at least 5 V.
    • Faulty power mirror switch
    • A short to ground in the wire

    Driver's MPCS Unit 

  6. Remove the driver's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
  7. Disconnect driver's MPCS unit connector A (40P).
    Fig 2: Identifying Driver's MPCS Unit Connector (40P) Terminals
    G08053972Courtesy of AMERICAN HONDA MOTOR CO., INC.
  8. 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 9.
  9. With the connector 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 10.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A5(1) BLK In all ignition switch positions Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground (G601) or an open in the ground wire
    • An open or high resistance in the wire
    A7(1) WHT Under all conditions Measure the voltage to ground: There should be battery voltage.
    • Blown No. 4 (40 A) fuse in the main under-hood fuse box
    • Blown No. 7 (10 A) fuse in the under-dash fuse/relay box
    • Faulty main under-hood fuse box
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    A8 GRY Under all conditions Check for continuity between A8 terminal and front passenger's MPCS unit connector A (28P) terminal No. 4: There should be continuity.
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    A16 YEL Under all conditions Connect A7 and A16 terminals, and A5 and A38 terminals: The left power mirror moves DOWN.
    • Faulty left power mirror actuator
    • An open or high resistance in the wire
    A38 PNK
    A17 RED Under all conditions Connect A7 and A17 terminals, and A5 and A38 terminals: The left power mirror swings RIGHT.
    • Faulty left power mirror actuator
    • An open or high resistance in the wire
    A38 PNK
    (1) Reconnect the connector to the driver's MPCS unit.

    Front Passenger's MPCS Unit 

  10. Remove the front passenger's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
  11. Disconnect front passenger's MPCS unit connector A (28P).
    Fig 3: Identifying Front Passenger's MPCS Unit Connector (28P) Terminals
    G08053973Courtesy of AMERICAN HONDA MOTOR CO., INC.
  12. 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 13.
  13. With the connector 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 14.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A7(1) BLK In all ignition switch positions Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground (G506) or an open in the ground wire
    • An open or high resistance in the wire
    A2(1) WHT Under all conditions Measure the voltage to ground: There should be battery voltage.
    • Blown No. 4(40 A) fuse in the main under-hood fuse box
    • Blown No. 7 (10 A) fuse in the under-dash fuse/relay box
    • Faulty main under-hood fuse box
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    A4 GRY Under all conditions Check for continuity between A4 terminal and driver's MPCS unit connector A (40P) terminal No. 8: There should be continuity.
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    A10 LT GRN Under all conditions Connect A2 and A10 terminals, and A7 and A25 terminals: The right power mirror moves UP.
    • Faulty right power mirror actuator
    • An open or high resistance in the wire
    A25 BLU
    A11 LT BLU Under all conditions Connect A2 and A11 terminals, and A7 and A25 terminals: The left power mirror swings RIGHT.
    • Faulty right power mirror actuator
    • An open or high resistance in the wire
    A25 BLU
    (1) Reconnect the connector to the front passenger's MPCS unit.
  14. 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.