PGM-FI Main Relay Harness Check
- Turn ignition off. Disconnect PGM-FI main relay 7-pin harness connector. Check for continuity between ground and main relay connector terminal No. 3 (Black wire). See Fig 1. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between main relay connector terminal No. 3 and ground connection. See WIRING DIAGRAMS
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- Ensure ignition is off. Measure voltage between ground and main relay connector terminal No. 7. See WIRING DIAGRAMS
article. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short in wire between fuse and main relay. See WIRING DIAGRAMS
article. See PCM POWER CIRCUIT FUSE IDENTIFICATION . Replace fuse in fuse/relay box.
- Turn ignition on. Measure voltage between ground and main relay connector terminal No. 5. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short in wire between fuse and main relay. See WIRING DIAGRAMS
article. See PCM POWER CIRCUIT FUSE IDENTIFICATION . Replace fuse in fuse/relay box.
- Put transmission in Park or Neutral (A/T) or depress clutch pedal (M/T). Turn ignition switch to START position. Measure voltmeter between ground and main relay connector terminal No. 2. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short in wire between START SIGNAL fuse and main relay connector terminal No. 2. See WIRING DIAGRAMS
article. Replace STARTER SIGNAL fuse.
- Turn ignition off. Disconnect PCM connector "A". See Figure. Check for continuity between PGM-FI main relay connector terminal No. 1 and PCM connector "A" terminal A16. See WIRING DIAGRAMS
article. If continuity exists, go to next step. If continuity does not exist, repair open in wire between main relay connector terminal No. 1 and PCM connector. See WIRING DIAGRAMS
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- Reconnect PCM and PGM-FI main relay connectors. Turn ignition on. Measure voltage between PCM connector terminal A10 and terminal A11 and between terminal A10 and terminal A24. If battery voltage exists, go to next step. If battery voltage does not exist, repair open in suspect wire between PCM connector terminal A11 or terminal A24 and main relay connector. See WIRING DIAGRAMS
article. If wires are okay, replace PGM-FI main relay.
- Turn ignition off. Measure voltage between PCM connector "A" terminal A10 and terminal A16. Turn ignition on. If one volt or less exists for 2 seconds after ignition is first turned on, check PGM-FI main relay. See PGM-FI MAIN RELAY TEST . If more than one volt exists, substitute a known-good PCM and recheck. If one volt or less now exists, replace original PCM.
Courtesy of AMERICAN HONDA MOTOR CO., INC.