LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2009 >> CSX Base, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 72 (Entry Lights Control System) >> Control Unit Input Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Control Unit Input Test

WARNING: This page is about a different car, the 2011 Acura TL, 2010 Acura TL, and 2009 Acura TL. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Before testing, troubleshoot the multiplex integrated control system first, using B-CAN System Diagnosis Test Mode A (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE A )

Driver's MICU 

  1. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode
  2. Remove the driver's dashboard undercover (see DRIVER'S DASHBOARD UNDERCOVER REMOVAL/INSTALLATION )
  3. Disconnect driver's under-dash fuse/relay box connectors D, P, Q, and R
    NOTE: All connector views are wire side of female terminals
    Fig 1: Driver's MICU Connector Terminals Chart
    G05988987Courtesy 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. Reconnect the connectors to the driver's under-dash fuse/relay box, and do these input tests at the following 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
    TEST CONDITION CAVITY CHART

    Cavity Wire Test condition Test Desired result Possible cause if desired result is not obtained
    Q1 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground (G402)
    • An open or high resistance in the wire
    Q2 BRN In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground(G401) or open in ground wire
    • An open or high resistance in the wire
    R2 BRN In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground(G401) or open in ground wire
    • An open or high resistance in the wire
    R5 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground(G402) or open in ground wire
    • An open or high resistance in the wire
    D4 LT GRN Left rear door open Measure the voltage to ground There should be less than 0 2V
    • Faulty left rear door switch
    • Faulty left rear door switch ground
    • An open in the wire
    Left rear door closed Measure the voltage to ground There should be about 5 V
    • Faulty left rear door switch
    • A short to ground in the wire
    D12 GRN Driver's door open Measure the voltage to ground There should be less than 0 2V
    • Faulty driver's door switch
    • An open in the wire
    Driver's door closed Measure the voltage to ground There should be about 5 V
    • Faulty driver's door switch
    • A short to ground in the wire
    P4 LT GRN Interior light switch in the DOOR position Attach to ground with a jumper wire; The individual map lights should come on
    • Blown No 16 (7 5 A) fuse in the under-hood fuse/relay box
    • Faulty roof console
    • An open or high resistance in the wire
    Q11
    *1    		 ORN Under all conditions Attach to ground with a jumper wire; The remote slot light should come on
    • Blown No 12 (10 A) fuse in the passenger's under-dash fuse/relay box
    • Faulty remote slot light
    • An open or high resistance in the wire
    Q11
    *2    		 ORN Under all conditions Attach to ground with a jumper wire; The ignition key light should come on
    • Blown No 16 (7 5 A) fuse in the under-hood fuse/relay box
    • Faulty ignition key light
    • An open or high resistance in the wire
    Q18
    *1    		 RED Remote key inserted into the reomote slot Measure the voltage to ground There should be less than 0 2V
    • Faulty remote slot
    • Faulty power control unit
    • An open or high resistance in the wire
    Remote key removed from the reomote slot Measure the voltage to ground There should be about 5 V
    • Faulty remote slot
    • Faulty power control unit
    • A short to ground in the wire
    Q18
    *2    		 RED Ignition key inserted into the ignition switch Measure the voltage to ground There should be less than 0 2V
    • Faulty ignition key switch
    • An open or high resistance in the wire
    • Poor ground(G403) or open in ground wire
    Ignition switch LOCK (0), and the ignition key removed from the ignition switch Measure the voltage to ground There should be about 5 V
    • Faulty ignition key switch
    • A short to ground in the wire
    *1: With Keyless access system
    *2: Without keyless access system

    Passenger's MICU 

  6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and remove the right kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS )
  7. Disconnect passenger's under-dash fuse/relay box connectors A, E, and G*1 (or H*2 )

    *1 Without SH-AWD

    *2 With SH-AWD

    NOTE: All connector views are wire side of female terminals
    Fig 2: Passenger's MICU Connector Terminals Chart
    G05988988Courtesy 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 to the passenger's under-dash fuse/relay box, and do these input tests at the following 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
    TEST CONDITION CAVITY CHART

    Cavity Wire Test condition Test Desired result Possible cause if desired result is not obtained
    A14 WHT Under all conditions Measure the voltage to ground There should be battery voltage
    • Blown No 15(10 A) fuse in the under-hood fuse/relay box
    • Faulty driver's under-dash fuse/relay box
    • An open or high resistance in the wire
    A35 BRN Ignition switch ON (II), or power mode ON Measure the voltage to ground There should be battery voltage
    • Blown No 12 (7 5 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
    A36 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground(G405) or open in ground wire
    • An open or high resistance in the wire
    A37 GRY In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground(G401) or open in ground wire
    • An open or high resistance in the wire
    E15 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground (G201) or an open in ground wire
    • An open or high resistance in the wire
    E16 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground(G203) or open in ground wire
    • An open or high resistance in the wire
    G14(1) or H25(2) LT GRN Right rear door open Measure the voltage to ground There should be less than 0 2V
    • Faulty right rear door switch
    • An open in the wire
    Right rear door closed Measure the voltage to ground There should be about 5 V
    • Faulty right rear door switch
    • Faulty right rear door switch ground
    • An open or high resistance in the wire
    G15(1) or H3(2) LT BLU Front passenger's door open Measure the voltage to ground There should be less than 0 2V
    • Faulty front passenger's door switch
    • Faulty front passenger's door switch ground
    • An open or high resistance in the wire
    Front passenger's door closed Measure the voltage to ground There should be about 5 V
    • Faulty front passenger's door switch
    • A short to ground in the wire
    (1) Without SH-AWD
    (2) With SH-AWD

    Door Multiplex Control Unit 

  10. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode, and remove the driver's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION )
  11. Disconnect the 37P connector from the door multiplex control unit
    Fig 3: Identifying Door Multiplex Control Unit 37P Connector Terminals
    G05988989Courtesy of AMERICAN HONDA MOTOR CO., INC.
  12. 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 13
  13. Reconnect the 37P connector to the door multiplex control unit, and do these input tests at the following connector
    • 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 14
    TEST CONDITION CAVITY CHART

    Cavity Wire Test condition Test Desired result Possible cause if desired result is not obtained
    13 WHT Under all conditions Measure the voltage to ground There should be battery voltage
    • Blown No 15 (10 A) fuse in the under-hood fuse/relay box
    • Faulty driver's under-dash fuse/relay box
    • An open in the wire
    32 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground (G401) or open in ground wire
    • An open or high resistance in the wire
    37 BLK In all ignition switch positions or all power modes Measure the voltage to ground There should be less than 0 2V
    • Poor ground (G402) or open in ground wire
    • An open or high resistance in the wire
    30 YEL Driver's door lock knob switch in LOCK Measure the voltage to ground There should be less than 0 2V
    • Poor ground(G401) or open in ground wire
    • Faulty driver's door lock knob switch
    • An open or high resistance 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
    31 WHT Driver's door lock knob switch in UNLOCK Measure the voltage to ground There should be less than 0 2V
    • Poor ground (G401) or open in ground wire
    • Faulty driver's door lock knob switch
    • An open or high resistance 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
  14. If multiple failures are found on more than one control unit, replace the driver's under-dash fuse/relay box (includes the driver's MICU) (see DRIVER'S UNDER-DASH FUSE/RELAY BOX (MICU) REMOVAL/INSTALLATION ) If input failures are related to a particular control unit, replace the control unit
scientia non olet · About LEMON Manuals