Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Key Interlock System Circuit Troubleshooting
SRS components are located in this area. Review the SRS component locations (see COMPONENT LOCATION INDEX ) and the precautions and procedures (see PRECAUTIONS AND PROCEDURES ) before doing repairs or service.
- Remove the driver's dashboard lower cover (see DRIVER'S DASHBOARD LOWER COVER REMOVAL/INSTALLATION ) and the steering column covers (see STEERING COLUMN REMOVAL AND INSTALLATION ).
- Turn the ignition switch to ACCESSORY (I). The shift lever must be in P.
- Disconnect the steering lock assembly connector.
- Check if the ignition switch can be turned to LOCK (0).
Can the ignition switch be turned to LOCK (0)?
YES -Go to step 5.
NO -Replace the ignition key cylinder/steering lock assembly (see STEERING LOCK REPLACEMENT ).
- Turn the ignition switch to ACCESSORY (I) or ON (II), and shift to N.
- Measure the voltage between steering lock assembly connector terminal No. 4 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 7.
NO -Check for open in with WHT/RED wire between the multiplex control unit and the steering lock assembly connector. If the wire is OK, substitute a known-good multiplex control unit and recheck.
- Turn the ignition switch to ACCESSORY (I), and shift to P.
- Remove the shift lever console trim (see SHIFT LEVER TRIM REMOVAL/INSTALLATION ).
- Disconnect the park pin switch connector (see PARK PIN SWITCH TEST ).
- Check for continuity between park pin switch connector terminals No. 1 and No. 2 while pushing the button of the shift lever in, and when released.
Is there continuity when pushing the button in, and no continuity when it's released?
YES -Check for open in the wire between the multiplex control unit and the park pin switch connector. If the wire is OK, replace the multiplex control unit.
NO -Replace the park pin switch (see PARK PIN SWITCH REPLACEMENT ).
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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