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
- Disconnect the key switch connector (7P) from the steering lock assembly.
- Connect the No. 7 terminal of the key switch connector to the battery positive terminal, and connect the No. 5 terminal to the battery negative terminal.
- Turn the ignition switch to ACC (I), then push the ignition key.
- Check the key interlock solenoid operation. A clicking sound should be heard while pushing the ignition key, and you should not be able to turn it to the OFF position.
Does the key interlock solenoid operate properly?
- YES - Go to step 5.
- NO - Faulty key interlock solenoid/switch. Replace the ignition key cylinder/steering lock assembly.
- Measure the voltage between the No. 7 terminal and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
- YES - Go to step 6.
- NO - Check for blown No. 47 (20A) fuse in the under-hood fuse/relay box. If the fuse is OK, repair open or short in the wire between the No. 7 terminal of the key switch connector and under-hood fuse/relay box.
- Disconnect the transmission gear selection switch connector on the rear of the shift lever.
- With the shift lever in Park and pushed to the right, check for continuity between the No. 4 and No. 10 terminals of the transmission gear selection switch connector.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
- YES - Go to step 8.
- NO - Repair open in the wires between the park pin switch and the transmission gear selection switch connector. If the wires are OK, replace the shift lever detent bracket assembly.
- Check for continuity between the No. 10 terminal of the transmission gear selection switch connector and the No. 5 terminal of the key switch connector.Fig 4: Checking Continuity Between No. 10 Terminal, Transmission Gear Selection Switch Connector & No. 5 Terminal, Key Switch Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
- YES - Go to step 9.
- NO - Repair open in the wire between No. 10 terminal of the transmission gear selection switch connector and the No. 5 terminal of the key switch connector.
- Check for continuity between the No. 4 terminal of the transmission gear selection switch connector and body ground.Fig 5: Checking Continuity Between No. 4 Terminal, Transmission Gear Selection Switch Connector & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
- YES - Check for loose terminal fit in the key switch connector and transmission gear selection switch connector. If necessary, substitute a known-good steering lock assembly.
- NO - Repair open in the wire between the No. 4 terminal of the transmission gear selection switch connector and ground (G501). Repair poor ground (G501).
Use the Manual With the Right Hardware
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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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