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Home >> Acura >> 2007 >> MDX >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Interior/Illumination Lights >> Entry Lights Control System >> Control Unit Input Test
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Control Unit Input Test

NOTE: Before testing the entry lights control system, troubleshoot the multiplex integrated control unit first, using B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A ).
  1. Turn the ignition switch to LOCK (0), and remove the left kick panel (see FRONT DOOR SILL AREA ).
  2. Disconnect under-dash fuse/relay box connectors E, F, G, H, P, Q, and W.
    NOTE: All connector views are wire side of female terminals.
    Fig 1: Identifying Under-Dash Fuse/Relay Box Connectors Terminals
    G05488012Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. 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 4.
  4. Reconnect the connectors, 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 5.
    CAVITY AND TEST CONDITION CHART

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    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
    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
    P13 PNK Ignition key inserted into the ignition switch Measure the voltage to ground:
    There should be less than 1 V.
    • Faulty ignition key switch
    • An open in the wire
    Ignition switch LOCK (0) and the ignition key removed from the ignition switch Measure the voltage to ground:
    There should be more than 5 V.
    • Faulty ignition key switch
    • A short to ground in the wire
    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
    F14 ORN Under all conditions Attach to ground:
    The ignition key light should come on.
    • Blown No. 4 (40 A) fuse in the main under-hood fuse box
    • Blown No. 6 (7.5 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • Faulty ignition key light
    • An open in the wire
    W4 LT GRN Under all conditions (Interior lights switch in DOOR position) Attach to ground:
    The map and ceiling lights should come on.
    • Blown No. 4 (40 A) fuse in the main under-hood fuse box
    • Blown No. 6 (7.5 A) fuse in the under-dash fuse/relay box
    • Faulty under-dash fuse/relay box
    • Blown map lights or ceiling light bulb(s)
    • An open in the wire

    Rear Fuse/Relay Box 

  5. Turn the ignition switch to LOCK (0).
  6. Remove the left rear trim (see TRIM REMOVAL/INSTALLATION - REAR SIDE AREA ).
  7. Disconnect rear fuse/relay box connector B (34P) and C (42P).
    Fig 2: Identifying Rear Fuse/Relay Box Connector Terminals
    G05488013Courtesy 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. 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 10.
    CAVITY AND TEST CONDITION CHART

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    B18 BLK Under all conditions Measure the voltage to ground:
    There should be less than 0.5 V.
    • Poor ground (G603, G604)
    • An open in the wire
    B29
    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
    • Faulty under-dash fuse/relay box
    • An open in the wire
    B23 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
    C6(1) 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
    (1) Without power tailgate

    Driver's MPCS Unit 

  10. Turn the ignition switch to LOCK (0).
  11. Remove the driver's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
  12. Disconnect driver's MPCS unit connectors A (40P) and B (UP).
    Fig 3: Identifying Driver's MPCS Unit Connectors Terminals
    G05488014Courtesy of AMERICAN HONDA MOTOR CO., INC.
  13. 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 14.
  14. 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 15.
    CAVITY AND TEST CONDITION CHART

    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A23 * A27 PNK * BRN Driver's door lock switch in LOCK Check for continuity:
    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:
    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 UNLOCK Check for continuity:
    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:
    There should be no continuity.
    • Faulty driver's door lock switch
    • A short to ground in the wire
  15. Reconnect the connectors, 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 16.
    CAVITY AND TEST CONDITION CHART

    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
    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
  16. 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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