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.

Fig 1: Connecting Key Switch Connector (7P) To Battery Voltage
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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?
1. YES - Go to step 5.
2. 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.

Fig 2: Measuring Voltage Between No. 7 Terminal And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 6.
2. 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.

Fig 3: Checking For Continuity Between The No. 4 & No. 10 Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 8.
2. 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?
1. YES - Go to step 9.
2. 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?
1. 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.
2. 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).