LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2012 >> TL Base >> Repair and Diagnosis (Single Page) >> Body & Frame >> Door Locks >> Keyless/Power Door Locks/Security System >> Control Unit Input Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Control Unit Input Test

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 ), and make sure the lighting system works properly.

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, F, G, N, Q, and R.
    NOTE: All connector views are wire side of female terminals.
    Fig 1: Identifying Driver's MICU F (33P), D (16P), N (16P), G (13P), Q (20P) & R (24P) Connector End Views
    G08071333Courtesy 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.
    NOTE: Before testing, make sure the No. 15 (10 A) fuse in the under-hood fuse/relay box is OK.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    D2 YEL Connect terminal F11 to terminal D2 (or D9), and terminal D9 (or D2) to body ground. Check actuator operation: The left rear door lock actuator should UNLOCK (or LOCK).
    • Faulty left rear door lock actuator
    • An open or high resistance in the wire
    D9 BLU
    D16 YEL Connect terminal F11 to terminal D16 momentarily Check actuator operation: The trunk lid release actuator should work.
    • Faulty trunk lid release actuator
    • Poor ground (G603) or an open in the ground wire
    • An open or high resistance in the wire
    F11 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
    • An open or high resistance in the wire
    F23 YEL Under all conditions Connect to ground with a jumper wire: The horns should sound.
    • Blown No. 10 (20 A) fuse in the under-hood fuse/relay box
    • Faulty horn relay circuit
    • Faulty horn
    • An open or high resistance in the wire
    D8 BLK Under all conditions Check for continuity to ground: There should be continuity.
    • Poor ground (G601)
    • An open or high resistance in the ground wire
    N1 ORN Connect terminal F11 to terminal N1 (or N2), and terminal N2 (or N1) to body ground. Check actuator operation: The driver's door lock actuator should UNLOCK (or LOCK).
    • Faulty driver's door lock actuator
    • An open or high resistance in the wire
    N2 BLU
  6. Reconnect the connectors to the driver's under-dash fuse/relay box, and do the following input tests:
  7. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
    • 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 8.
    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 0.2 V.
    • Poor ground (G402)
    • An open or high resistance in the ground wire
    Q2 BRN In all ignition switch positions or all power modes Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G401)
    • An open or high resistance in the ground wire
    R2 BRN In all ignition switch positions or all power modes Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G401)
    • An open or high resistance in the ground wire
    R5 BLK In all ignition switch positions or all power modes Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G402)
    • An open or high resistance in the ground wire
    D4 LT GRN Left rear door open Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty left rear door switch
    • Faulty left rear door switch ground
    • An open or high resistance 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
    D5 WHT Trunk lid open Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty trunk lid latch switch
    • Poor ground (G603) or an open in the ground wire
    • An open or high resistance in the wire
    Trunk lid closed Measure the voltage to ground: There should be about 5 V.
    • Faulty trunk lid latch switch
    • A short to ground in the wire
    D12 GRN Driver's door open Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty driver's door switch
    • Faulty driver's door switch ground
    • An open or high resistance 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
    D15 GRY Left rear door lock knob switch in UNLOCK Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty left rear door lock knob switch
    • Poor ground (G601) or an open in the ground wire
    • An open or high resistance in the wire
    Left rear door lock knob switch in LOCK Measure the voltage to ground: There should be about 5 V.
    • Faulty left rear door lock knob switch
    • A short to ground in the wire
    G3 GRN Hood open Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty security hood switch
    • Poor ground (G302) or an open in the ground wire
    • An open or high resistance in the wire
    Hood closed Measure the voltage to ground: There should be about 5 V.
    • Faulty security hood switch
    • A short to ground in the wire
    Q18(1) BRN Ignition key inserted into the ignition switch Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty ignition key switch
    • Poor ground (G403) or an open in the ground wire
    • An open or high resistance in the 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
    Q18(2) BRN Keyless access remote inserted into the remote slot Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty power control unit
    • Poor ground (G402) or an open in the ground wire
    • An open or high resistance in the wire
    Keyless access remote removed from the remote slot Measure the voltage to ground: There should be about 5 V.
    • Faulty power control unit
    • A short to ground in the wire
    (1) Without keyless access system
    (2) With keyless access system

    Passenger's MICU 

  8. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  9. Remove the passenger's kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ).
  10. Disconnect passenger's under-dash fuse/relay box connectors A, E, 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: Identifying Passenger's MICU A (38P), E (18P), G (16P) (w/o SH-AWD) & H (38P) (w/ SH-AWD) Connector End Views
    G08071334Courtesy of AMERICAN HONDA MOTOR CO., INC.
  11. 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 12.
  12. 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 13.
    NOTE: Before testing, make sure the No. 15(10 A) fuse in the under-hood fuse/relay box is OK.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    G8(1) or H7(2) BLK Under all conditions Check for continuity to ground: There should be continuity.
    • Poor ground(G651)
    • An open or high resistance in the ground wire
    A20 BLU Connect terminal A14 to terminal A20 (or A38), and terminal A38 (or A20) to body ground. Check actuator operation: The front passenger's door lock actuator should UNLOCK (or LOCK).
    • Faulty front passenger's door lock actuator
    • An open or high resistance in the wire
    A38 YEL
    G1(1) YEL Connect terminal A14 to terminal G1 (or G9), and terminal G9 (or G1)to body ground. Check actuator operation: The right rear door lock actuator should LOCK (or UNLOCK).
    • Faulty right rear door lock actuator
    • An open or high resistance in the wire
    G9(1) BLU
    H27(2) YEL Connect terminal A14 to terminal H27 (or H1), and terminal H1 (or H27) to body ground. Check actuator operation: The right rear door lock actuator should LOCK (or UNLOCK).
    • Faulty right rear door lock actuator
    • An open or high resistance in the wire
    H1(2) BLU
    (1) Without SH-AWD
    (2) With SH-AWD
  13. Reconnect the connectors to the passenger's under-dash fuse/relay box, 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, go to step 14.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    A9 RED Under all conditions Measure the voltage to ground: There should be battery voltage.
    • Blown No. 1-2 (AS F/B STD) (40 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
    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 0.2 V.
    • Poor ground(G405)
    • An open or high resistance in the ground wire
    A37 GRY In all ignition switch positions or all power modes Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G401)
    • An open or high resistance in the ground wire
    E15 BLK In all ignition switch positions or all power modes Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G203)
    • An open or high resistance in the ground wire
    G14(1) or H25(2) LT GRN Right rear door open Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty right rear door switch
    • Faulty right rear door switch ground
    • An open or high resistance in the wire
    Right rear door closed Measure the voltage to ground: There should be about 5 V.
    • Faulty right rear door switch
    • A short to ground 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 0.2 V.
    • 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
    G6(1) or H22*3 PNK Right rear door lock knob switch in UNLOCK Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty right rear door lock knob switch
    • Poor ground (G651) or an open in the ground wire
    • An open or high resistance in the wire
    Right rear door lock knob switch in LOCK Measure the voltage to ground: There should be about 5 V.
    • Faulty right rear door lock knob switch
    • A short to ground in the wire
    (1) Without SH-AWD
    (2) With SH-AWD

    Door Multiplex Control Unit 

  14. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  15. Remove the driver's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
  16. Disconnect the 37P connector from the power window master switch.
    Fig 3: Identifying Door Multiplex Control Unit Connector End View
    G08071335Courtesy of AMERICAN HONDA MOTOR CO., INC.
  17. 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 all the terminals look OK, go to step 18.
  18. Reconnect the driver's door harness to driver's door subharness.
  19. With the connector 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 test proves OK, go to step 20.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    27 PNK Disconnect the front passenger's power window switch 37P connector and moonroof control unit/motor 14P connector Check for continuity between power window master switch 37P connector terminal No. 27 and front passenger's power window switch 37P connector terminal No. 29: There should be continuity. An open in the UART wire
    Check for continuity to ground: There should be no continuity. A short to ground in the wire
  20. Reconnect the 37P connector to the power window master switch, 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, go to step 21.
    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 or high resistance in the wire
    14 LT GRN Ignition switch ON (II), or power mode ON Measure the voltage to ground: There should be battery voltage.
    • Blown No. 16 (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
    25 WHT Under all conditions Measure the voltage to ground: There should be battery voltage.
    • Blown No. 24 (20 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
    32 BLK In all ignition switch positions or all power modes Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G401)
    • An open or high resistance in the ground wire
    37 BLK In all ignition switch positions or all power modes Measure the voltage to ground: There should be less than 0.2 V.
    • Poor ground(G402)
    • An open or high resistance in the ground wire
    28 PNK Driver's door key cylinder switch in LOCK Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty driver's door key cylinder switch
    • Poor ground (G401) or an open in the ground wire
    • An open or high resistance in the wire
    Driver's door key cylinder switch in neutral or UNLOCK Measure the voltage to ground: There should be about 5 V.
    • Faulty driver's door key cylinder switch
    • A short to ground in the wire
    29 BRN Driver's door key cylinder switch in UNLOCK Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty driver's door key cylinder switch
    • Poor ground (G401) or an open in the ground wire
    • An open or high resistance in the wire
    Driver's door key cylinder switch in neutral or LOCK Measure the voltage to ground: There should be about 5 V.
    • Faulty driver's door key cylinder switch
    • A short to ground in the wire
    30 YEL Driver's door lock knob switch in LOCK Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty driver's door lock knob switch
    • Poor ground (G401) or an open in the ground wire
    • An open or high resistance in the wire
    Driver's door lock knob switch in neutral or UNLOCK Measure the voltage to ground: There should be about 5 V.
    • 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 0.2 V.
    • Faulty driver's door lock knob switch
    • Poor ground (G401) or an open in the ground wire
    • An open or high resistance in the wire
    Driver's door lock knob switch in neutral or LOCK Measure the voltage to ground: There should be about 5 V.
    • Faulty driver's door lock knob switch
    • A short to ground in the wire

    Front Passenger's Power Window Switch 

  21. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  22. Remove the front passenger's door panel (see FRONT DOOR PANEL REMOVAL/INSTALLATION ).
  23. Disconnect the 37P connector from the front passenger's power window switch.
    Fig 4: Identifying Front Passenger's Power Window Switch Connector End View
    G08071336Courtesy of AMERICAN HONDA MOTOR CO., INC.
  24. 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 25.
  25. With the connector 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 test proves OK, go to step 26.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    29 PNK Disconnect the front passenger's power window switch 37P connector Check for continuity between power window master switch 37P connector terminal No. 27 and front passenger's power window switch 37P connector terminal No. 29: There should be continuity. An open in the UART wire
    Check for continuity to ground: There should be no continuity. A short to ground in the UART wire
  26. Reconnect the 37P connector to the front passenger's power window switch, 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, go to step 27.
    Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
    25 GRN Under all conditions Measure the voltage to ground: There should be battery voltage.
    • Blown No. 13 (20 A) fuse in the passenger's under-dash fuse/relay box
    • 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 0.2 V.
    • Poor ground (G405)
    • An open or high resistance in the ground wire
    34 PUR Front passenger's door lock knob switch in UNLOCK Measure the voltage to ground: There should be less than 0.2 V.
    • Faulty front passenger's door lock knob switch
    • Poor ground (G405) or an open in the ground wire
    • An open or high resistance in the wire
    Front passenger's door lock knob switch in LOCK Measure the voltage to ground: There should be about 5 V.
    • Faulty front passenger's door lock knob switch
    • A short to ground in the wire
  27. 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 AND INSTALLATION ). If input failures are related to a particular control unit, replace the control unit.
scientia non olet · About LEMON Manuals