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 repair or service.
- Turn the ignition switch to ACC (I). The shift lever must be in the P position.
- Disconnect the steering lock assembly connector.
- Check if the ignition switch can be turned to the LOCK (0) position.
Can the ignition switch be turned the LOCK (0) position?
YES - Go to step 4.
NO - Replace the ignition key cylinder/steering lock assembly (see LOCK LEVER INSPECTION/ADJUSTMENT ).
- Remove the ATP P relay and park pin switch relay, and test the relays (see RELAYS
).
Are the relays OK?
YES - Go to step 5.
NO - Replace the faulty relay.
- Remove the shift lever assembly.
- Shift the shift lever to P position.
- At park pin switch side, check for continuity between park pin switch connector terminals No. 1 and No. 3. Do not pull the shift lever.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Faulty the park pin switch, replace the shift lever assembly (see SHIFT LEVER REMOVAL ). The park pin switch is not available from the shift lever assembly.
NO - Go to step 8.
- Check for continuity between park pin switch relay 4P socket terminal No. 3 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Repair short to body ground in the wire between the park pin switch relay and the park pin switch.
NO - Go to step 9.
- Disconnect the transmission range switch connector.
- Check for continuity between ATP P relay 4P socket terminal No. 3 and transmission range switch connector terminal No. 4.Fig 3: Checking Continuity Between ATP P Relay 4P Socket Terminal No. 3 And Transmission Range Switch Connector Terminal No. 4
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Test the transmission range switch (see TRANSMISSION RANGE SWITCH TEST ). If the transmission range switch is OK, check for poor connections or loose terminals between the ATP P relay and the transmission range switch.
NO - Repair open in the wire between the ATP P relay and the transmission range switch.
NO RELATED
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.