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 ICM Black/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, check for an open in Black/Yellow wire between ignition switch and ICM.
- Turn ignition on. Check for voltage between ground and ICM Green wire. See Fig 1
. 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 Green wire between ICM and ignition coil.
- Turn ignition switch off. Disconnect PCM 32-pin "A" connector. Check for continuity in Yellow/Green wire between PCM 32-pin connector terminal A20 and ICM. See the WIRING DIAGRAMS
article. If continuity exists, go to next step. If continuity does not exist, repair open in Yellow/Green wire.
- Check for continuity between ground and Yellow/Green wire. If continuity does not exist, go to next step. If continuity exists, repair short to ground in Yellow/Green wire.
- Reconnect PCM 32-pin connector "A" to PCM. Disconnect instrument cluster 16-pin connector. Check for continuity in Blue wire between ICM and tachometer. 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. Reconnect instrument cluster connector. Replace ICM.
Courtesy of AMERICAN HONDA MOTOR CO., INC.