LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Honda >> 2012 >> Accord SE >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Anti-Theft Systems >> Keyless/Power Door Locks/Security System (4-CYL) >> 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 unit 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.
  • If there is malfunction about keyless/security answerback and lighting in the panic function operation, check the MICU input test of the exterior light.

Driver's MICU 

  1. Turn the ignition switch to LOCK (0).
  2. Remove the driver's dashboard lower cover (see DRIVER'S DASHBOARD LOWER COVER 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 MICU Connectors Terminals
    G07344537Courtesy 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 5.
      NOTE: Before testing, make sure the No. 25 (10 A) fuse in the under-dash fuse/relay box is OK.
      TROUBLE SYMPTOMS CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      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
      F15 RED Under all conditions Measure the voltage to ground:
      There should be battery voltage.
      • Blown No. 1-2(ASF/BSTD) (40 A) fuse in the under-hood fuse/relay box
      • An open or high resistance in the wire
      F18 YEL Under all conditions Measure the voltage to ground:
      There should be battery voltage.
      • Blown No. 3-2 (DR F/B) (40 A) fuse(1) or No. 3-4 (DR F/B) (60 A) fuse(2) in the under-hood fuse/relay box
      • An open or high resistance in the wire
      D2 (4-door) 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 (4-door) ORN
      D16 ORN Connect terminal F11 to terminal D16 momentarily Check actuator operation:
      The trunk lid release actuator should work.
      • Faulty trunk lid release actuator
      • Poor ground (G602) or an open in the ground wire
      • An open or high resistance in the wire
      F23 GRN/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
      • Faulty horn
      • Faulty horn ground
      • An open or high resistance in the wire
      N1 YEL 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 ORN
      (1) '08-10 models LX-S and LX-P PZEV, and '11-12 models LX-S, and LX and LX PZEV
      (2) Except '08-10 models LX-S and LX-P PZEV, and '11-12 models LX-S, and LX and LX PZEV
  6. Reconnect the connectors to the driver'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  7.
      TROUBLE SYMPTOMS CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      Q1 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G502)
      • An open or high resistance in the ground wire
      Q2 BRN In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G501)
      • An open or high resistance in the ground wire
      R2 BRN In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G501)
      • An open or high resistance in the ground wire
      R5 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G502)
      • An open or high resistance in the ground wire
      D8 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G601)
      • An open or high resistance in the ground wire
      D4 (4-door) 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 (G602) 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 BRN 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 real door lock knob switch
      • Poor ground (3601) 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 real door lock knob switch
      • A short to ground in the wire
      G3 GRN/BLK 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 WHT 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 (G503) 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

    Passenger's MICU 

  7. Turn the ignition switch to LOCK (0).
  8. Remove the passenger's kick panel.
  9. Disconnect passenger's under-dash fuse/relay box connectors A, D, E, and G*1 (or H*2).

    *1: '08-10 models LX, LX PZEV, LX-P, LX-P PZEV, and '11-12 USA models 4-door LX

    *2: Except '08-10 models LX, LX PZEV, LX-P, LX-P PZEV, and '11-12 USA models 4-door LX

    NOTE: All connector views are wire side of female terminals.
    Fig 2: Identifying Passenger MICU Connectors Terminals
    G00521462Courtesy 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, 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  12.
      NOTE: Before testing, make sure the No. 15(10 A) fuse in the under-hood fuse/relay box is OK.
      TROUBLE SYMPTOMS CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      A20 LT GRN 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 RED
      G1(1)(4-door) RED 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)(4-door) LT GRN
      H27(2)(4-door) RED 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)(4-door) LT GRN
      (1) '08-10 models LX, LX PZEV, LX-P, LX-P PZEV, and '11-12 USA models 4-door LX
      (2) Except '08-10 models LX, LX PZEV, LX-P, LX-P PZEV, and '11-12 USA models 4-door LX
  12. 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  13.
      TROUBLE SYMPTOMS CHART

      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(ASF/BSTD) (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) Measure the voltage to ground:
      There should be battery voltage.
      • Blown No. 5 (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
      A37 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V
      • Poor ground (G505) or an open in the ground wire
      • An open or high resistance in the wire
      A36(1) BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V
      • Poor ground (G505) or an open in the ground wire
      • An open or high resistance in the wire
      E15 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V
      • Poor ground (G201) or an open in the ground wire
      • An open or high resistance in the wire
      E16 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V
      • Poor ground (G201)or an open in the ground wire
      • An open or high resistance in the wire
      D22 GRN Under all conditions Measure the voltage to ground:
      There should be less than 0.2 V(4)
      • Faulty navigation display unit(3) and/or audio unit
      • Poor ground (G402) or an open in the ground wire
      • An open or high resistance in the wire
      G8(1) BLK Under all conditions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G651) or an open in the ground wire
      • An open or high resistance in the wire
      H7(2)
      G14(1)(4-door) 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
      • An open or high resistance in the wire
      H25(2)(4-door) 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) GRN 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
      H3(2) GRN 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
      H22 (4-door) GRY 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
      • An open or high resistance in the wire
      (1) '08-10 models LX, LX PZEV, LX-P, LX-P PZEV, and '11-12 USA models 4-door LX
      (2) Except '08-10 models LX, LX PZEV, LX-P, LX-P PZEV, and '11-12 USA models 4-door LX
      (3) With navigation system
      (4) If the factory-installed audio unit or audio-navigation unit is removed from the vehicle, this voltage will be between 10-12 V.

    Door Multiplex Control Unit 

  13. Turn the ignition switch to LOCK (0).
  14. Open and close the driver's door, then remove the power window master switch.
  15. Disconnect the 37P connector from the power window master switch.
    Fig 3: Identifying Door Multiplex Control Unit Connector Terminals
    G07344539Courtesy 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 connector still disconnected, do the following input tests:
    • If any test indicates a problem, find and correct the cause, then recheck the system.
    • If the input test proves OK, go to step  18.
      TROUBLE SYMPTOMS CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      27 BLU Disconnect front passenger's power window switch 37 P connector and disconnect 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 in the UART wire
      33 BLU Disconnect driver's under-dash fuse/relay box connector P (20P) Check for continuity between power window master switch 37P connector terminal No. 33 and driver's under-dash fuse/relay box connector P (20P) terminal No. 5:
      There should be continuity.      		 An open in the B-CAN wire
      35 PNK Disconnect driver's under-dash fuse/relay box connector P (20P) Check for continuity between power window master switch 37P connector terminal No. 35 and driver's under-dash fuse/relay box connector P (20P) terminal No. 6:
      There should be continuity.      		 An open in the B-CAN wire
  18. 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  19.
      TROUBLE SYMPTOMS CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      32 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G501)
      • An open or high resistance in the ground wire
      37 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G502)
      • An open or high resistance in the ground wire
      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) 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 BRN 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
      28 ORN Driver's door key cylinder switch in LOCK Measure the voltage to ground:
      There should be less than 0.2 V.
      • Faulty driver's key cylinder switch
      • Poor ground (G501) or an open in the ground wire
      • An open or high resistance in the wire
      Driver's door key cylinder switch in UNLOCK Measure the voltage to ground:
      There should be about 5 V.
      • Faulty driver's 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 (G501) 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 (G501) 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 (G501) 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 

  19. Turn the ignition switch to LOCK (0).
  20. Remove the front passenger's power window switch.
  21. Disconnect the 37P connector from the front passenger's power window switch.
    Fig 4: Identifying Front Passenger Power Window Switch Connector Terminals
    G07344540Courtesy of AMERICAN HONDA MOTOR CO., INC.
  22. 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 the input test proves OK, go to step  23.
  23. 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  24.
      TROUBLE SYMPTOMS CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      29 BLU Disconnect the power window master switch 37P connector and the moonroof control unit/motor 14P connector Check for continuity between terminal No. 29 and power window master switch 37P connector terminal No. 27:
      There should be continuity.      		 An open in the UART wire
      Check for continuity between terminal No. 29 and moonroof control unit/motor 14P connector terminal No. 11:
      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
  24. 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  25.
      TROUBLE SYMPTOMS CHART

      Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained
      37 BLK In all ignition switch positions Measure the voltage to ground:
      There should be less than 0.2 V.
      • Poor ground (G505)
      • An open or high resistance in the ground wire
      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
      34 WHT 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 (G505)or an open in the ground wire
      • An open or high resistance in the wire
      Front passenger's door lock knob switch in neutral or 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
  25. 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).

    If input failures are related to a particular control unit, replace the control unit.

scientia non olet · About LEMON Manuals