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
- Check the A/T system DTCs with the HDS.
Are DTCs indicated?
YES - Go to DTC troubleshooting GENERAL TROUBLESHOOTING INFORMATION .
NO - Go to step 2.
- Move the shift lever to P and set the parking brake.
- Remove the column cover (see COLUMN COVER REMOVAL/INSTALLATION ).
- Disconnect the steering lock assembly 6P connector.
- Turn the ignition switch to ACCESSORY (I).
- Check if the ignition switch can be turned to LOCK (0).
Can the ignition switch be turned to LOCK (0)?
YES -Go to step 7.
NO -Replace the ignition key cylinder/steering lock assembly (see CHECK OF LOCK LEVER FORCE ).
- Check the No. 35 (7.5A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES - Go to step 8.
NO - Replace the fuse. If the fuse blows again, repair a short to ground in the No. 35 (7.5A) fuse circuit.
- Make sure the ignition switch is turned to LOCK (0).
- Disconnect connector R (20P) from the under-dash fuse/relay box.
- Check for continuity between steering lock assembly 6P connector terminal No. 3 and body ground.Fig 1: Checking Continuity Between Steering Lock Assembly 6P Connector Terminal No. 3 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair a short to body ground in the wire between the key interlock solenoid and the MICU.
NO -Go to step 11.
- Check for continuity between under-dash fuse/relay box connector R (20P) terminal No. 8 and steering lock 6P connector terminal No. 3.
Is there continuity?
YES - Go to step 12.
NO - Repair an open or high resistance in the wire between the key interlock solenoid and the MICU.
- Remove the shift lever (see SHIFT LEVER REMOVAL ).
- Disconnect the A/T gear position indicator panel light/D3 switch/park pin switch 6P connector.
- Do the park pin switch test Park Pin Switch Test .
Is switch OK?
YES - 15.
NO - Check for park pin switch installation, if the switch installation is OK. Replace the switch PARK PIN SWITCH REPLACEMENT and retest.
- Check for continuity between A/T gear position indicator panel light/D3 switch/park pin switch 6P connector terminal No. 1 and body ground.Fig 3: Checking Continuity Between A/T Gear Position Indicator Panel Light/D3 Switch/Park Pin Switch 6P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair a short to body ground in the wire between A/T gear position indicator panel light/D3 switch/park pin switch 6P connector terminal No. 1 and the MICU.
NO -Go to step 16.
- Check for continuity between A/T gear position indicator panel light/D3 switch/park pin switch 6P connector terminal No. 2 and body ground.Fig 4: Checking Continuity Between A/T Gear Position Indicator Panel Light/D3 Switch/Park Pin Switch 6P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
NO -Go to step 17.
YES -Repair an open or high resistance in the wire between AT gear position indicator panel light/D3 switch/park pin switch and body ground (G503).
- Check the A/T system Data List with the HDS.
- Do the transmission range switch test TRANSMISSION RANGE SWITCH TEST
.
Is switch is OK?
YES - Go to step 19.
NO - Check the transmission range switch installation. If the switch installation is OK, replace the switch TRANSMISSION RANGE SWITCH REPLACEMENT and retest.
- Disconnect the transmission range switch 10P connector.
- Check for continuity between under-dash fuse/relay box connector F (34P) terminal No. 27 and transmission range switch 10P connector terminal No. 6.Fig 5: Checking Continuity Between Under-Dash Fuse/Relay Box Connector F (34P) Terminal No. 27 And Transmission Range Switch 10P Connector Terminal No. 6
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 21.
NO -Repair an open or high resistance in the wire between the under-dash fuse/relay box and the transmission range switch.
- Check for continuity between transmission range switch harness terminal No. 10 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Faulty MICU, replace the under-dash fuse/relay box UNDER-DASH FUSE/RELAY BOX .
NO - Repair an open or high resistance in the ground wire or poor ground (G101).
Is the transmission range switch indicated ON when the shift lever is in P, and is the transmission range switch indicated OFF when the shift lever is shifted to any position other than P?
YES - Go to step 2.
NO - Go to step18.
NO RELATED
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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.