Ignition Control Module (ICM) Input Test
- Turn ignition off. Remove distributor cap, rotor and leak cover. Disconnect wires from ICM. See Fig 1
. Turn ignition on. Check for voltage between ground and Black/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, check Black/Yellow wire between fuse No. 9 (15-amp) in underdash fuse/relay box and ICM. See the WIRING DIAGRAMS
article. Repair wire as necessary.
- Turn ignition on. Check for voltage between ground and White/Blue wire. If battery voltage exists, go to next step. If battery voltage does not exist, check ignition coil. Replace coil as necessary. If ignition coil is okay, check for an open in White/Blue wire between ICM and ignition coil. See the WIRING DIAGRAMS
article.
- Check for continuity in Blue wire between tachometer test connector and ICM. If continuity exists, go to next step. If continuity does not exist, repair open in Blue wire.
- Check for continuity between ground and Blue wire. If continuity exists, repair short to ground in Blue wire. If continuity does not exist, wiring is okay. Replace ICM.
Courtesy of AMERICAN HONDA MOTOR CO., INC.