2012 Acura RLFACTORY OEM SERVICE PROCEDURE

Front Passenger's MPCS Unit Input Test/Replacement

  1. Turn the ignition switch to LOCK (0).
  2. Remove the front passenger's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
  3. Disconnect front passenger's MPCS unit (A) connectors A (28P) and B (14P).
    Fig 1: Disconnecting Front Passenger's MPCS Unit Connectors (28P) And B (14P)
    G07363610Courtesy 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.
      TEST CONDITION AND WIRE REFERENCE CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      A4 GRY Driver's under-dash fuse/relay box connector X (39P) and right rear power window switch 14P connector disconnected Check for continuity between terminal A4 and driver's under-dash fuse/relay box connector X (39P) terminal No. 15, and terminal A4 and right rear power window switch 14P connector terminal No. 2:
      There should be continuity.
      • Faulty passenger's under-dash fuse/relay box
      • An open or high resistance in the wire
      Check for continuity to ground:
      There should be no continuity.
      • Faulty passenger's under-dash fuse/relay box
      • A short to ground in the wire
      B2 LT BLU Front passenger's power window switch in AUTO position Check for continuity between the terminals:
      There should be continuity.
      • Faulty front passenger's power window switch
      • An open or high resistance in the wire
      A24 BLU
      B2 LT BLU Front passenger's power window switch released Check for continuity between the terminals:
      There should be no continuity.
      • Faulty front passenger's power window switch
      • A short to ground in the wire
      A24 BLU
      B13 GRY Front passenger's power window switch in UP position Check for continuity between the terminals:
      There should be continuity.
      • Faulty front passenger's power window switch
      • An open or high resistance in the wire
      A24 BLU
      B13 GRY Front passenger's power window switch released Check for continuity between the terminals:
      There should be no continuity.
      • Faulty front passenger's power window switch
      • A short to ground in the wire
      A24 BLU
      B11 BRN Front passenger's power window switch in DOWN position Check for continuity between the terminals:
      There should be continuity.
      • Faulty front passenger's power window switch
      • An open or high resistance in the wire
      A24 BLU
      B11 BRN Front passenger's power window switch released Check for continuity between the terminals:
      There should no continuity.
      • Faulty front passenger's power window switch
      • A short to ground in the wire
      A24 BLU
      B9 WHT Under all conditions Connect battery power to terminal A24 and ground terminal B9. The LED should come on.
      • Faulty front passenger's power window switch
      • Faulty LED
      • An open or high resistance in the wire
      A24 BLU
      B10 RED Front passenger's power window switch DOWN Check for continuity between the terminals:
      There should be continuity between terminals B10 and A22, and no continuity between terminals B10 and B12.
      • Faulty front passenger's power window switch
      • An open or high resistance in the wire
      • A short to ground in the wire
      B12 PNK
      A22 PUR
      B10 RED Front passenger's power window switch in released Check for continuity between the terminals:
      There should be continuity between terminals B10 and B12, and no continuity between terminals B10 and A22.
      • Faulty front passenger's power window switch
      • An open or high resistance in the wire
      • A short to ground in the wire
      B12 PNK
      A22 PUR
      B1 LT GRN Connect terminals B8 and B1 with a jumper wire, and connect terminal B7 to body ground. Check the front passenger's power window motor operation:
      The motor should run (the window should go down).
      • Blown No. 3 (30 A) fuse in the passenger's under-dash fuse/relay box
      • Faulty front passenger's power window motor
      • An open or high resistance in the wire
      B7 BLU Connect terminals B8 and B7 with a jumper wire, and connect terminal B1 to body ground. Check the front passenger's power window motor operation:
      The motor should run (the window should go up).
      • Blown No. 3 (30 A) fuse in the passenger's under-dash fuse/relay box
      • Faulty front passenger's power window motor
      • An open or high resistance in the wire
  6. Reconnect the connectors to the front passenger's MPCS unit, 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 control unit must be faulty; replace the front passenger's MPCS unit and go to step 7.
      TEST CONDITION AND WIRE REFERENCE CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      A7 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G506)
      • An open or high resistance in the ground wire
      B14 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G506)
      • An open or high resistance in the ground wire
      A2 WHT Under all conditions Measure the voltage to ground:
      There should be battery voltage.
      • Blown No. 15 (40 A) fuse in the under-hood fuse/relay box
      • Blown No. 7 (10 A) fuse in the driver's under-dash fuse/relay box
      • Faulty passenger's under-dash fuse/relay box
      • An open or high resistance in the wire
      B8 GRN Under all conditions Measure the voltage to ground:
      There should be battery voltage.
      • Blown No. 22 (70 A) fuse in the under-hood fuse/relay box
      • Blown No. 3 (30 A) fuse in the passenger's under-dash fuse/relay box
      • Faulty passenger's under-dash fuse/relay box
      • An open or high resistance in the wire
      B3 GRN Ignition switch ON (II) Measure the voltage to ground:
      There should be battery voltage.
      • Faulty front passenger's MPCS unit
      • An open or high resistance in the wire
      B6 YEL Under all conditions Measure the continuity to ground:
      There should be continuity.
      • Poor ground (G506) or an open in the ground wire
      • Faulty front passenger's MPCS unit
      • An open or high resistance in the wire
      B5 BLU Ignition switch ON (II) and front passenger's power window motor runs by connecting terminals B8 and B1 with a jumper wire, and connect terminal B7 to body ground. Measure the voltage between terminals B5 and B6:
      An analog meter should alternate between 0 V and about 5 V (a digital voltmeter reads about 2.5 V while the window moves).
      • Blown No. 3 (30 A) fuse in the passenger's under-dash fuse/relay box
      • Faulty front passenger's MPCS unit
      • Faulty front passenger's power window motor
      • An open or high resistance in the wire
      B4 ORN Ignition switch ON (II) and front passenger's power window motor runs by connecting terminals B8 and B1 with a jumper wire, and connect terminal B7 to body ground. Measure the voltage between terminals B4 and B6:
      An analog meter should alternate between 0 V and about 5 V (a digital voltmeter reads about 2.5 V while the window moves).
      • Blown No. 3 (30 A) fuse in the passenger's under-dash fuse/relay box
      • Faulty front passenger's MPCS unit
      • Faulty front passenger's power window motor
      • An open or high resistance in the wire
  7. Reset the power window control unit (see RESETTING THE POWER WINDOW CONTROL UNIT  ).
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.