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Home >> Acura >> 2007 >> MDX >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Keyless/Power Door Locks/Security System >> Control Unit Input Test
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Control Unit Input Test

NOTE: Before testing the keyless/power door locks/security system control unit, troubleshoot the multiplex integrated control unit first, using B-CAN system Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).

MICU 

  1. Turn the ignition switch to LOCK (0).
  2. Remove the left kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ).
  3. Disconnect under-dash fuse/relay box connectors E, F, H, K, N, Q, and P.
    NOTE: All connector views are wire side of female terminals.
    Fig 1: Identifying Under-Dash Fuse/Relay Box Connectors E, F, H, K, N, Q, And P
    G05487887Courtesy 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, make these input tests at the connectors.
    • 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.
    CONTROL INPUT TEST REFERENCE

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    E2 BRN Connect battery power to the E2 (E8) terminal, and the E8(E2) terminal to body ground. Check actuator operation: The left and right rear door lock actuators should LOCK (UNLOCK).
    • Faulty left rear door lock actuator
    • Faulty right rear door lock actuator
    • An open in the wire
    E8 GRY
    K2 GRY Connect battery power to the K12 (K2) terminal, and the K2 (K12) terminal to body ground. Check actuator operation: The driver's door lock actuator should LOCK (UNLOCK).
    • Faulty driver's door lock actuator
    • An open in the wire
    K12 BRN
    N7 BRN Connect battery power to the N7 (N9) terminal, and the N9 (N7) terminal to body ground. Check actuator operation: The front passenger's door lock actuator should LOCK (UNLOCK).
    • Faulty front passenger's door lock actuator
    • An open in the wire
    N9 GRY
    F5(1) PNK Connect battery power to the F5 terminal. Check tailgate release actuator operation:
    The tailgate should open.
    • Faulty tailgate release actuator
    • Poor ground(G701)
    • Faulty rear fuse/relay box
    • An open in the wire
    (1) Without power tailgate
  6. Reconnect the connectors, then turn the ignition switch ON (II), and make these input tests at the connectors.
    • 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 7.
    CONTROL INPUT TEST REFERENCE

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    P1 BRN Under all conditions Measure the voltage to ground:
    There should be less than 0.5 V.
    • Poor ground(G502)
    • An open in the wire
    E9 BLK Under all conditions Measure the voltage to ground:
    There should be less than 0.5 V.
    • Poor ground(G601)
    • An open in the wire
    H9
    Q4
    E15 GRN Driver's door open Measure the voltage to ground:
    There should be less than 1 V.
    • Faulty driver's door switch
    • An open in the wire
    Driver's door closed Measure the voltage to ground:
    There should be more than 5 V.
    • Faulty driver's door switch
    • A short to ground in the wire
    H12 LT GRN Front passenger's door open Measure the voltage to ground:
    There should be less than 1 V.
    • Faulty front passenger's door switch
    • An open in the wire
    Front passenger's door closed Measure the voltage to ground:
    There should be more than 5 V.
    • Faulty front passenger's door switch
    • A short to ground in the wire
    Q2 GRY Right rear door open Measure the voltage to ground:
    There should be less than 1 V.
    • Faulty right rear door switch
    • An open in the wire
    Right rear door closed Measure the voltage to ground:
    There should be more than 5 V.
    • Faulty right rear door switch
    • A short to ground in the wire
    Q8 GRN Left rear door open Measure the voltage to ground:
    There should be less than 1 V.
    • Faulty left rear door switch
    • An open in the wire
    Left rear door closed Measure the voltage to ground:
    There should be more than 5 V.
    • Faulty left rear door switch
    • A short to ground in the wire
    P12 RED Under all conditions Measure the voltage to ground:
    There should be less than 1 V.
    • Faulty connection at the audio unit, navigation unit, and/or rear controller and screen
    • Faulty audio unit
    • Faulty navigation unit
    • Faulty rear controller and screen
    • An open in the wire
    • Poor ground (G504)
    P16 GRN Transmission range switch in P position Measure the voltage to ground:
    There should be less than 1 V.
    • Faulty transmission range switch
    • An open in the wire
    • Poor ground(G101)
    Transmission range switch in any other position than P Measure the voltage to ground:
    There should be more than 5 V.
    • Faulty transmission range switch
    • A short to ground in the wire

    Rear Fuse/Relay Box 

  7. Turn the ignition switch to LOCK (0).
  8. Remove the le ft rear trim (see TRIM REMOVAL/INSTALLATION - REAR SIDE AREA ).
  9. Disconnect rear fuse/relay box connectors B (34P) and C (42P).
    Fig 2: Identifying Rear Fuse/Relay Box Connectors B (34P) And C (42P)
    G05487888Courtesy of AMERICAN HONDA MOTOR CO., INC.
  10. 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 11.
  11. With the connectors still disconnected, make these input tests at the connectors.
    • 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 12.
    CONTROL INPUT TEST REFERENCE

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    C23(1) PNK Connect battery power to the C23 terminal momentarily. Check tailgate release actuator operation:
    The tailgate should open.
    • Poor ground(G701)
    • Faulty tailgate release actuator
    • An open in the wire
    C37 ORN Connect battery power to the C37 terminal momentarily. Check keyless buzzer operation:
    The keyless buzzer should sound.
    • Faulty keyless buzzer
    • Poor ground (G702)(2) (G603)(3)
    • An open in the wire
    (1) Without power tailgate
    (2) '07 model
    (3) '08 model
  12. Reconnect the connectors, then turn the ignition switch ON (II), and make these input tests at the connectors.
    • 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 13.
    CONTROL INPUT TEST REFERENCE

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    B4 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
    • An open in the wire
    C6 LT GRN Tailgate open Measure the voltage to ground:
    There should be less than 1 V.
    • Poor ground(G702)
    • Faulty tailgate latch switch
    • An open in the wire
    Tailgate closed Measure the voltage to ground:
    There should be more than 5 V.
    • Faulty tailgate latch switch
    • A short to ground in the wire
    C7(1) ORN Tailgate outer handle pulled Measure the voltage to ground:
    There should be less than 1 V.
    • Poor ground(G702)
    • Faulty tailgate outer handle switch
    • An open in the wire
    Tailgate outer handle released Measure the voltage to ground:
    There should be more than 5 V.
    • Faulty tailgate outer handle switch
    • A short to ground in the wire
    (1) Without power tailgate

    Driver's MPCS Unit 

  13. Turn the ignition switch to LOCK (0).
  14. Remove the driver's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
  15. Disconnect driver's MPCS unit connectors A(40P) and B (14P).
    Fig 3: Identifying Driver'S MPCS Unit Connectors A(40P) And B (14P)
    G05487889Courtesy of AMERICAN HONDA MOTOR CO., INC.
  16. 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 17.
  17. With the connectors still disconnected, make these input tests at the connectors.
    • 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 18.
    CONTROL INPUT TEST REFERENCE

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A8 GRY Under all conditions Check for continuity between the A8 terminal and the front passenger's MPCS unit connector A (28P) No. 4 terminal: There should be continuity.
    • Faulty under-dash fuse/relay box
    • An open in the wire
    Check for continuity to ground:
    There should be no continuity.
    • Faulty under-dash fuse/relay box
    • A short to ground in the wire
    A23
    •
    A27    		 PNK
    •
    BRN    		 Driver's door lock switch in UNLOCK Check for continuity between the terminals:
    There should be continuity.
    • Faulty driver's door lock switch
    • An open in the wire
    Driver's door lock switch in neutral or LOCK Check for continuity between the terminals:
    There should be no continuity.
    • Faulty driver's door lock switch
    • A short to ground in the wire
    A24
    •
    A27    		 RED
    •
    BRN    		 Driver's door lock switch in LOCK Check for continuity between the terminals:
    There should be continuity.
    • Faulty driver's door lock switch
    • An open in the wire
    Driver's door lock switch in neutral or UNLOCK Check for continuity between the terminals:
    There should be no continuity.
    • Faulty driver's door lock switch
    • A short to ground in the wire.
    A27
    •
    A4    		 BRN
    •
    GRY    		 Connect the A7 and A27 terminals, and A4 and A5 terminals with jumper wires Check the driver's door lock switch lights:
    The switch light should come on.
    • Faulty driver's door lock switch
    • Blown bulb
    • An open in the wire
  18. Reconnect the connectors, then turn the ignition switch ON (II), and make these input tests at the connectors.
    • 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 19.
    CONTROL INPUT TEST REFERENCE

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A5 BLK Under all conditions Measure the voltage to ground:
    There should be less than 0.5 V.
    • Poor ground (G601)
    • An open in the wire
    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
    • Blown No. 7 (10 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • An open in the wire
    A27 BRN
    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 in the wire
    A1 GRN Driver's door lock knob switch in UNLOCK Measure the voltage to ground:
    There should be less than 1 V.
    • Poor ground (G601)
    • Faulty driver's door lock knob switch
    • An open in the wire
    Driver's door lock knob switch in LOCK Measure the voltage to ground:
    There should be battery voltage.
    • Faulty driver's door lock knob switch
    • A short to ground in the wire
    A2 PUR Driver's door lock knob switch in LOCK Measure the voltage to ground:
    There should be less than 1 V.
    • Poor ground (G601)
    • Faulty driver's door lock knob switch
    • An open in the wire
    Driver's door lock knob switch in UNLOCK Measure the voltage to ground:
    There should be battery voltage.
    • Faulty driver's door lock knob switch
    • A short to ground in the wire
    A21 BLU Driver's door key cylinder switch in UNLOCK Measure the voltage to ground:
    There should be less than 1 V.
    • Poor ground (G601)
    • Faulty driver's door key cylinder switch ? An open in the wire
    Driver's door key cylinder switch in neutral or LOCK Measure the voltage to ground:
    There should be battery voltage.
    • Faulty driver's door key cylinder switch
    • A short to ground in the wire
    A22 LT BLU Driver's door key cylinder switch in LOCK Measure the voltage to ground:
    There should be less than 1 V.
    • Poor ground (G601)
    • Faulty driver's door key cylinder switch
    • An open in the wire
    Driver's door key cylinder switch in UNLOCK Measure the voltage to ground:
    There should be battery voltage.
    • Faulty driver's door key cylinder switch
    • A short to ground in the wire
    A6 GRN Left rear door lock knob switch in UNLOCK Measure the voltage to ground:
    There should be less than 1 V.
    • Poor ground (G601)
    • Faulty left rear door lock knob switch
    • An open in the wire
    Left rear door lock knob switch in LOCK Measure the voltage to ground:
    There should be battery voltage.
    • Faulty left rear door lock knob switch
    • A short to ground in the wire

    Front Passenger's MPCS Unit 

  19. Turn the ignition switch to LOCK (0).
  20. Remove the front passenger's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
  21. Disconnect front passenger's MPCS unit connectors A(28P) and B (14P).
    Fig 4: Identifying Front Passenger'S MPCS Unit Connectors A(28P)
    G05487890Courtesy of AMERICAN HONDA MOTOR CO., INC.
    Fig 5: Identifying Front Passenger'S MPCS Unit Connectors B (14P)
    G05487891Courtesy of AMERICAN HONDA MOTOR CO., INC.
  22. 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 23.
  23. With the connectors still disconnected, make these input tests at the connectors.
    • 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 24.
    CONTROL INPUT TEST REFERENCE

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A4 GRY Under all conditions Check for continuity between the A4 terminal and the driver's MPCS unit connector A (40P) No. 8 terminal:
    There should be continuity.
    • Faulty under-dash fuse/relay box
    • An open in the wire
    Check for continuity to ground:
    There should be no continuity.
    • Faulty under-dash fuse/relay box
    • A short to ground in the wire
    A15
    •
    A20    		 PNK
    •
    BRN    		 Front passenger's door lock switch in LOCK Check for continuity between the terminals:
    There should be continuity.
    • Faulty front passenger's door lock switch
    • An open in the wire
    Front passenger's door lock switch in neutral or UNLOCK Check for continuity between the terminals:
    There should be no continuity.
    • Faulty front passenger's door lock switch
    • A short to ground in the wire
    A16
    •
    A20    		 ORN
    •
    BRN    		 Front passenger's door lock switch in UNLOCK Check for continuity between the terminals:
    There should be continuity.
    • Faulty front passenger's door lock switch
    • An open in the wire
    Front passenger's door lock switch in neutral or LOCK Check for continuity between the terminals:
    There should be no continuity.
    • Faulty front passenger's door lock switch
    • A short to ground in the wire.
    A20
    •
    A1    		 BRN
    •
    GRY    		 Connect the A2 and A20 terminals, and A1 and A7 terminals with jumper wires Check the front passenger's door lock switch lights:
    The switch light should come on.
    • Faulty front passenger's door lock switch
    • Blown bulb
    • An open in the wire
  24. Reconnect the connectors, then turn the ignition switch ON (II), and make these input tests at the connectors.
    • 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 25.
    CONTROL INPUT TEST REFERENCE

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A7 BLK Under all conditions Measure the voltage to ground:
    There should be less than 0.5 V.
    • Poor ground(G506)
    • An open in the wire
    B14 BLK Under all conditions Measure the voltage to ground:
    There should be less than 0.5 V.
    • Poor ground(G507)
    • An open in the wire
    A2 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 under-dash fuse/relay box
    • An open in the wire
    A20 BRN
    A17 RED Front passenger's door lock knob switch in UNLOCK Measure the voltage to ground:
    There should be less than 1 V.
    • Poor ground (G506)
    • Faulty front passenger's door lock knob switch
    • An open in the wire
    Front passenger's door lock knob switch in LOCK Measure the voltage to ground:
    There should be battery voltage.
    • Faulty front passenger's door lock knob switch
    • A short to ground in the wire
    A26 PUR Right rear door lock knob switch in UNLOCK Measure the voltage to ground:
    There should be less than 1 V.
    • Poor ground(G606)
    • Faulty right rear door lock knob switch
    • An open in the wire
    Right rear door lock knob switch in LOCK Measure the voltage to ground:
    There should be battery voltage.
    • Faulty right rear door lock knob switch
    • A short to ground in the wire
  25. If multiple failures are found on more than one control unit, replace the under-dash fuse/relay box (includes the MICU) (see REMOVAL AND INSTALLATION ). If input failures are related to a particular control unit, replace the control unit.
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