Ignition Control Module (ICM) Input Test (Prelude)
- Turn ignition off. Remove distributor cap, rotor, leak cover and cap seal. Disconnect wires from ICM. See Fig 4. Turn ignition on. Check for voltage between body ground and Black/Yellow wire. If battery voltage exists, go to next step. If battery voltage does not exist, check for open in Black/Yellow wire between ignition switch and ICM. See WIRING DIAGRAMS article.
- Ensure ignition is on. Check for voltage between body ground and Green wire. See Fig 4. If battery voltage exists, go to next step. If battery voltage does not exist, check ignition coil operation. See IGNITION COIL TEST (PRELUDE) . Replace ignition coil as necessary. If ignition coil is okay, check for open in Green wire between ICM and ignition coil.
- Turn ignition switch off. Disconnect PCM connector "A" (32-pin connector). Check for continuity of Yellow/Green wire between PCM connector "A" (32-pin connector) terminal No. 20 and ICM. If continuity exists, go to next step. If continuity does not exist, repair open in Yellow/Green wire.
- Check for continuity between body ground and Yellow/Green wire. If continuity does not exist, go to next step. If continuity exists, check for short to ground in Yellow/Green wire.
- Reconnect PCM connector "A" (32-pin connector). Disconnect instrument cluster 16-pin connector. Check continuity of Blue wire between ICM and tachometer. If continuity exists, go to next step. If continuity does not exist, repair open in Blue wire between ICM and tachometer.
- Check for continuity between body ground and Blue wire. If continuity exists, check for short to ground in Blue wire. If continuity does not exist, wiring is okay at this time. Replace ICM. Reconnect instrument cluster 16-pin connector.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Courtesy of AMERICAN HONDA MOTOR CO., INC.