LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2000 >> 1.6EL XS, Automatic >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Keyless Entry System/Security Alarm System >> Control Unit Input Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Control Unit Input Test

SRS components are located in this area. Review the SRS component locations, precautions, and procedures in the SRS section (24) before performing repairs or service.

  1. Slide the driver's seat fully forward so you can reach the control unit from behind the seat.
  2. Disconnect the 12P and 18P connectors from the keyless/security control unit.
  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, make the following input tests at the connector terminals.

    • If any test indicates a problem, find and correct the cause, then recheck the system.
    • If all the input tests prove OK, the control unit must be faulty; replace it.
      Fig 1: Identifying Security Control Unit Connectors
      G06288610Courtesy of AMERICAN HONDA MOTOR CO., INC.
      Fig 2: Identifying Security Control Unit Connectors
      G06288611Courtesy of AMERICAN HONDA MOTOR CO., INC.

Keyless Entry System: 

Disconnect the 12P and 18P connectors from the unit.

TEST CONDITION CHART

Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained
A10 BLK Under all conditions Check for continuity to ground: There should be continuity.
  • Poor ground (G552)
  • An open in the wire
A12 WHT/GRN Under all conditions Check for voltage to ground: There should be battery voltage.
  • Blown No. 52 (20 A) fuse in the under-hood fuse/relay box
  • An open in the wire
A1 BLK/YEL Ignition switch ON (II) Check for voltage to ground: There should be battery voltage.
  • Blown No. 14 (7.5 A) fuse in the under-dash fuse/relay box
  • An open in the wire
A2 LT GRN/RED Ceiling light switch in "middle" position Connect to ground: The ceiling light should come on.
  • Blown No. 43 (7.5 A) fuse in the under-dash fuse box
  • Blown ceiling light bulb
  • Faulty ceiling light
  • An open in the wire
A3 YEL/RED Connect the YEL/RED terminal to the A12 (WHT/GRN) terminal, and the WHT/RED terminal to the A10 (BLK) terminal momentarily. Check door lock operation: Passenger's door should unlock.
  • Blown No. 52 (20 A) fuse in the under-hood fuse/relay box
  • Faulty actuator
  • An open in the wire
  • Poor ground (G552)
A9 WHT/RED
A4 BLU/RED Connect the BLU/RED terminal to the A12 (WHT/GRN) terminal momentarily. Check trunk lock operation: Trunk lid should open.
  • Blown No. 52 (20 A) fuse in the under-hood fuse/relay box
  • Faulty actuator
  • An open in the wire
  • Poor ground (G601)
A5 YEL/RED Connect the YEL/RED terminal to the A12 (WHT/GRN) terminal, and the WHT/RED terminal to the A10 (BLK) terminal momentarily. Check door lock operation: Driver's door should unlock.
  • Blown No. 52 (20 A) fuse in the under-hood fuse/relay box
  • Faulty actuator
  • An open in the wire
  • Poor ground (G552)
A9 WHT/RED
B10 BLU/RED Ignition key inserted into the ignition key switch Check for voltage to ground: There should be 1 V or less.
  • Poor ground (G401, G402)
  • Faulty ignition key switch
  • An open in the wire
  • Short in the wire
Ignition key removed from the ignition key switch. Check for voltage to ground: There should be 4 V or more.

Reconnect the 12P and 18P connectors to the unit.

TEST CONDITION CHART

Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained
B2 GRN/ORN Driver's door lock switch in UNLOCK Check for voltage to ground: There should be 1 V or less.
  • Poor ground (G551)
  • Faulty driver's door lock switch
  • An open in the wire
  • Short in the wire
Driver's door lock switch in neutral Check for voltage to ground: There should be 4 V or more.
B3 BLU/RED Driver's door lock knob in UNLOCK Check for voltage to ground: There should be 1 V or less.
  • Poor ground (G551)
  • Faulty driver's door lock knob switch
  • An open in the wire
  • Short in the wire
Driver's door lock knob in LOCK Check for voltage to ground: There should be 4 V or less.
B5 BLU/RED Passenger's door lock knob in UNLOCK Check for voltage to ground: There should be 1 V or less.
  • Poor ground (G551)
  • Faulty passenger's door lock knob switch
  • An open in the wire
  • Short in the wire
Passenger's door lock knob in LOCK Check for voltage to ground: There should be 4 V or more.
B7 BLU/WHT Driver's door lock knob in UNLOCK Check for voltage to ground: There should be 4 V or more.
  • Poor ground (G551)
  • Faulty driver's door lock knob switch
  • An open in the wire
  • Short in the wire
Driver's door lock knob in LOCK Check for voltage to ground: There should be 1 V or less.
B11 GRN/WHT Driver's door lock switch in neutral Check for voltage to ground: There should be 4 V or more.
  • Poor ground (G551)
  • Faulty driver's door lock switch
  • An open in the wire
  • Short in the wire
Driver's door lock switch in LOCK Check for voltage to ground: There should be 1 V or less.
B12 GRY/YEL All doors open Check for voltage to ground: There should be 1 V or less.
  • Faulty door switch
  • Faulty keyless/security control unit
  • An open in the wire
All doors closed Check for voltage to ground: There should be battery voltage.
Fig 3: Identifying Security Control Unit Connectors
G06288612Courtesy of AMERICAN HONDA MOTOR CO., INC.

Security System: 

Disconnect the 12P and 18P connectors from the unit.

TEST CONDITION CHART

Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained
A10 BLK Under all conditions Check for continuity to ground: There should be continuity.
  • Poor ground (G552)
  • An open in the wire
A12 WHT/GRN Under all conditions Check for voltage to ground: There should be battery voltage.
  • Blown No. 51 (20 A) fuse in the under-hood fuse/relay box
  • An open in the wire
A1 BLK/YEL Ignition switch ON (II) Check for voltage to ground: There should be battery voltage.
  • Blown No. 14 (7.5 A) fuse in the under-dash fuse/relay box
  • An open in the wire
A6 ORN Shift lever in (P) or (N) (A/T), or clutch pedal fully depressed (M/T) and ignition switch START (III) Check for voltage to ground: There should be battery voltage.
  • Faulty starter cut relay
  • Faulty clutch interlock switch (M/T)
  • Faulty A/T gear position switch (A/T)
  • Blown No. 31 (7.5 A) fuse in the under-dash fuse/relay box
A7 RED Under all conditions Connect to ground: The security indicator should come on.
  • Blown No. 47 (7.5 A) fuse in the under-hood fuse/relay box
  • Faulty security indicator
  • An open in the wire
A8 GRY Under all conditions Connect to ground: The horns should sound.
  • Blown No. 52 (15 A) fuse in the under-hood fuse/relay box
  • Faulty horn relay
  • Faulty horns
  • An open in the wire
A11 RED/GRN Connect the RED/GRN terminal to the A12 (WHT/GRN) terminal Check the taillights: The taillights should come on.
  • Blown No. 32 (7.5 A) fuse in the under-dash fuse/relay box
  • An open in the wire
  • Faulty taillight system
B1 LT GRN Hood open Check for continuity to ground: There should be continuity.
  • Faulty hood switch
  • Poor ground (G201)
  • An open in the wire
Hood closed Check for continuity to ground: There should be no continuity.
B16 BLU/RED Under all conditions Connect to ground: The headlights should come on.
  • Faulty security system headlight relay
  • Blown No. 25 (10 A) fuse in the under-dash fuse/relay box
  • Faulty headlight system
  • An open in the wire
B18 BLU/ORN Ignition switch at START (III) Check voltage to ground: There should be battery voltage.
  • Blown No. 31 (7.5 A) fuse in the under-dash fuse/relay box
  • An open in the wire

Reconnect the 12P and 18P connectors to the unit.

TEST CONDITION CHART

Cavity Wire Test Condition Test: Desired result Possible cause if result is not obtained
B6 RED/BLU Passenger's door key cylinder switch in UNLOCK Check for voltage to ground: There should be 1 V or less.
  • Poor ground (G551)
  • Faulty passenger's door key cylinder switch
  • An open in the wire
  • Short in the wire
Passenger's door key cylinder switch in NEUTRAL Check for voltage to ground: There should be 4 V or more.
B8 BLU Driver's door key cylinder switch in UNLOCK Check for voltage to ground: There should be 1 V or less.
  • Poor ground (G551)
  • Faulty driver's door key cylinder switch
  • An open in the wire
  • Short in the wire
Driver's door key cylinder switch in NEUTRAL Check for voltage to ground: There should be 4 V or more.
B9 ORN Trunk lid open Check for voltage to ground: There should be 1 V or less.
  • Poor ground (G601)
  • Faulty driver's door lock knob switch
  • An open in the wire
  • Short in the wire
Trunk lid closed Check for voltage to ground: There should be 4 V or more.
B17 RED/YEL Passenger's door key cylinder switch in LOCK Check for voltage to ground: There should be 1 V or less.
  • Poor ground (G551)
  • Faulty passenger's door key cylinder switch
  • An open in the wire
  • Short in the wire
Passenger's door key cylinder switch in NEUTRAL Check for voltage to ground: There should be 4 V or more.
Driver's door key cylinder switch in LOCK Check for voltage to ground: There should be 1 V or less.
  • Poor ground (G551)
  • Faulty driver's door key cylinder switch
  • An open in the wire
  • Short in the wire
Driver's door key cylinder switch in NEUTRAL Check for voltage to ground: There should be 4 V or more.
scientia non olet · About LEMON Manuals