Starter Switch Signal Circuit Troubleshooting

Measure voltage between ECM connector terminals A24 and B20 with the ignition switch in the start position (III) and the clutch pedal pressed.

Fig 1: Measuring Voltage Between ECM Connector Terminals A24 And B20
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES -The starter switch signal is OK.
2. NO -Go to step 2.
Inspect the No. 9 (7.5 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
1. YES -Repair open in the wire between the ECM (A24) and the No. 9 (7.5 A) fuse.
2. NO -Repair short in the wire between the ECM (A24) and the No. 9 (7.5 A) fuse or the PGM-FI main relay (IGP). Replace the No. 9 (7.5 A) fuse.