2012 Acura RLFACTORY OEM SERVICE PROCEDURE

Driver's MPCS Unit Input Test/Replacement

  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: Disconnecting Driver's MPCS Unit Connectors (40P) And B (14P)
    G07363609Courtesy 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
      A8 GRY Driver's under-dash fuse/relay box connector J (21P) and power window master switch 6P connector disconnected Check for continuity between terminal A8 and driver's under-dash fuse/relay box connector J (21P) terminal No. 1, and terminal A8 and power window master switch 6P connector terminal No. 6:
      There should be continuity.      		 An open or high resistance in the wire
      Check for continuity to ground:
      There should be no continuity.      		 A short to ground in the wire
      B10 PUR 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
      B12 ORN
      B10 PUR Driver's power window switch released Check for continuity between the terminals:
      There should be continuity.
      • Faulty power window master switch
      • An open or high resistance in the wire
      B12 ORN
      B10 PUR 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
      B13 PNK
      B10 PUR 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
      B13 PNK
      B9 LT 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
      B2 LT BLU
      B9 LT GRN 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
      B2 LT BLU
      B1 LT GRN Connect terminals B8 and B1 with a jumper wire, and connect terminal B7 to body ground. Check the driver's power window motor operation:
      The motor should run (the window should go down).
      • Blown No. 27 (30 A) fuse in the driver's under-dash fuse/relay box
      • Faulty driver'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 driver's power window motor operation:
      The motor should run (the window should go up).
      • Blown No. 27 (30 A) fuse in the driver's under-dash fuse/relay box
      • Faulty driver's power window motor
      • An open or high resistance in the wire
  6. Reconnect the connectors to the driver'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 driver'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
      A5 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground(G601)
      • Faulty driver's under-dash fuse/relay box
      • 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 (G601)
      • Faulty driver's under-dash fuse/relay box
      • An open or high resistance in the ground wire
      A7 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 driver's 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. 23 (P/W) (50 A) fuse in the under-hood fuse/relay box
      • Blown No. 27 (30 A) fuse in the driver's under-dash fuse/relay box
      • Faulty driver's 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 (10 A) fuse in the driver's under-dash fuse/relay box
      • Faulty driver's under-dash fuse/relay box
      • An open or high resistance in the wire
      B3 RED 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
      B6 GRN Under all conditions Measure the continuity to ground:
      There should be continuity.
      • Poor ground (G601) or an open in the ground wire
      • Faulty driver's MPCS unit
      • An open or high resistance in the wire
      B5 GRY Ignition switch ON (II) and driver'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. 27 (30 A) fuse in the driver's under-dash fuse/relay box
      • Faulty driver's MPCS unit
      • Faulty driver's power window motor
      • An open or high resistance in the wire
      B4 BRN Ignition switch ON (II) and driver'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. 27 (30 A) fuse in the driver's under-dash fuse/relay box
      • Faulty driver's MPCS unit
      • Faulty driver'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.

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