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Driver's MPCS Unit Input Test

  1. Turn the ignition switch to LOCK (0).
  2. Remove the driver's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
  3. Disconnect driver's MPCS unit (A) connectors A (40P) and B (14P).
    Fig 1: Identifying Driver's MPCS Unit Connectors A (40P) And B (14P)
    G08055412Courtesy 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.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A8 GRY Under-dash fuse/relay box connector J (21P) and power window master switch 14P connector disconnected Check for continuity between terminal A8 and under-dash fuse/relay box connector J (12P) terminal No. 1, and terminal A8 and power window master switch 14P connector terminal No. 13: There should be continuity. An open or high resistance in the wire
    Check for continuity to ground: There should be no continuity. Short to ground in the wire
    A39 WHT Under all conditions Measure the voltage to ground: There should be battery voltage.
    • Blown No. 3 (P/W) (50 A) fuse in the main under-hood fuse box
    • Faulty main under-hood fuse box
    • Faulty under-dash fuse/relay box
    • Faulty power window relay
    • An open or high resistance in the wire
    A3 ORN Connect terminal A39 to body ground, and connect terminals A3 and B8 with a Jumper wire. Check the left rear power window motor operation: The motor should run (the power window should go up).
    • Blown No. 24 (20 A) fuse in the under-dash fuse/relay box
    • Blown No. 3 (P/W) (50 A) fuse in the main under-hood fuse box
    • Blown No. 27 (30 A) fuse in the under-dash fuse/relay box
    • Faulty main under-hood fuse box
    • Faulty under-dash fuse/relay box
    • Poor ground (G601) or an open in the ground wire
    • Faulty power window relay
    • Faulty left rear power window switch
    • Faulty left rear power window motor
    • An open or high resistance in the wire
    A32 YEL Connect terminal A39 to body ground, and connect terminals A32 and B8 with a jumper wire. Check the left rear power window motor operation: The motor should run (the power window should go down).
    B1 YEL Connect terminals B8 and B1, and terminals B7 and B14 with jumper wires. Check the driver's power window motor operation: The motor should run (the power window should go down).
    • Blown No. 27 (30 A) fuse in the under-dash fuse/relay box
    • Blown No. 3 (P/W) (50 A) fuse in the main under-hood fuse box
    • Faulty main under-hood fuse box
    • Faulty under-dash fuse/relay box
    • Poor ground (G601) or an open in the ground wire
    • Faulty driver's power window motor
    • An open or high resistance in the wire
    B7 BLU Connect terminals B8 and B7, and terminals B1 and B14 with jumper wires. Check the driver's power window motor operation: The motor should run (the power window should go up).
    B9 B2 LT GRN GRN Driver's power window switch in UP position Check for continuity between the terminals: There should be continuity.
    • Faulty power window master switch
    • An open or high resistance in the wire
    Driver's power window switch released Check for continuity between the terminals: There should be no continuity.
    • Faulty power window master switch
    • A short to ground in the wire
    B10.B12 PUR.ORN Under all conditions (except pressing the driver's power window switch DOWN position) Check for continuity between the terminals: There should be continuity.
    • Faulty power window master switch
    • An open or high resistance in the wire
    Driver's power window switch in DOWN position Check for continuity between the terminals: There should be no continuity.
    • Faulty power window master switch
    • A short to ground in the wire
    B10.B13 PUR.RED Driver's power window switch in DOWN position Check for continuity between the terminals: There should be continuity.
    • Faulty power window master switch
    • An open or high resistance in the wire
    Driver's power window switch released Check for continuity between the terminals: There should be no continuity.
    • Faulty power window master switch
    • A short to ground in the wire
  6. Reconnect the connectors, 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, replace the driver's MPCS unit, then go to step 7.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A5 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
    • Faulty under-dash fuse/relay box
    B14
    A7 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
    • Faulty main under-hood fuse box
    • Blown No. 7 (10 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    B8 WHT Under all conditions Measure the voltage to ground: There should be battery voltage.
    • Blown No. 3 (P/W) (50 A) fuse in the main under-hood fuse box
    • Faulty main under-hood fuse box
    • Blown No. 27 (30 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    A25 YEL Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage.
    • Blown No. 21 (7.5 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open or high resistance in the wire
    B3 PNK Ignition switch ON (II) Measure the voltage to ground: There should be battery voltage.
    • Faulty driver's MPCS unit
    • An open or high resistance in the wire
    • A short to ground in the wire
    B4 BRN Ignition switch ON (II), and driver's power window moving up or down. Measure the voltage between terminals B4 and B6: An analog voltmeter should alternate between 0 V and about 5 V (a digital voltmeter should read about 2.5 V while the window moves).
    • Faulty power window master switch
    • Faulty driver's MPCS unit
    • Faulty driver's power window motor
    • An open or high resistance in the wire
    • A short to ground in the wire
    B5 GRY Ignition switch ON (II), and driver's power window moving up or down. Measure the voltage between terminals B5 and B6: An analog voltmeter should alternate between 0 V and about 5 V (a digital voltmeter should read about 2.5 V while the window moves).
    B6 WHT Ignition switch ON (II) Check for continuity to ground: There should be continuity.
    • Poor ground (G601) or an open in the ground wire
    • Faulty under-dash fuse/relay box
    • Faulty driver's MPCS unit
    • An open or high resistance in the wire
    B9 LT GRN Under all conditions, disconnect the driver's power window motor 6P connector. Measure the voltage to ground: There should be battery voltage.
    • Faulty driver's MPCS unit
    • Faulty power window master switch
    • An open or high resistance in the wire
    • A short to ground in the wire
  7. Reset the power window control unit 
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