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PGM-FI Main Relay Circuit Check: Prelude

  1. Turn ignition off. Remove PGM-FI main relay. PGM-FI main relay is located under left side of instrument panel, near steering column. See COMPONENT LOCATIONS . Check for continuity between ground and PGM-FI main relay harness connector terminal No. 3 (Black wire). See Figure. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between PGM-FI main relay connector terminal No. 3 and ground connection. Ground connection is located below and behind distributor cap, under VTEC pressure switch. See WIRING DIAGRAMS article.
  2. Measure voltage between ground and PGM-FI main relay harness connector terminal No. 7 (White/Green wire). See WIRING DIAGRAMS article. If battery voltage exists, go to next step. If battery voltage does not exist, check for a blown No. 4 ACG-S (10-amp) fuse in fuse/relay box located on left side of engine compartment, next to battery. If fuse is blown, check for a short in White/Green wire between PGM-FI main relay and No. 4 ACG S (15-amp) fuse. If fuse is okay, check for open in White/Green wire between PGM-FI main relay and No. 4 ACG S (15-amp) fuse. See WIRING DIAGRAMS article.
  3. Turn ignition on. Measure voltage between ground and PGM-FI main relay harness connector terminal No. 5 (Red/Orange wire). If battery voltage exists, go to next step. If battery voltage does not exist, check for a blown No. 23 FUEL PUMP SRS (15-amp) fuse in under-dash fuse/relay box. If fuse is blown, check for short in Red/Orange wire between No. 23 FUEL PUMP SRS (15-amp) fuse and PGM-FI main relay. If fuse is okay, check for open in Red/Orange wire between No. 23 FUEL PUMP SRS (15-amp) fuse and PGM-FI main relay. See WIRING DIAGRAMS article.
  4. Depress clutch pedal. Turn ignition switch to START position. Measure voltage between ground and PGM-FI main relay harness connector terminal No. 2 (Blue/Red wire). If battery voltage exists, go to next step. If battery voltage does not exist, check for a blown No. 2 STARTER SIGNAL (7.5-amp) fuse in under-dash fuse/relay box. If fuse is blown, check for short in Blue/Red wire between No. 2 STARTER SIGNAL (7.5-amp) fuse and PGM-FI main relay. If fuse is okay, check for open in Blue/Red wire between No. 2 STARTER SIGNAL (7.5-amp) fuse and PGM-FI main relay. See WIRING DIAGRAMS article.
  5. Turn ignition off. Disconnect PCM 32-pin connector "A". Check for continuity in Green/Orange wire between PGM-FI main relay harness connector terminal No. 1 and PCM 32-pin harness connector "A" terminal No. 16. See PIN VOLTAGE CHARTS article. If continuity exists, go to next step. If continuity does not exist, repair open in Green/Orange wire between PGM-FI main relay and PCM 32-pin connector "A". See WIRING DIAGRAMS article.
  6. Reconnect PCM and PGM-FI main relay connectors. Turn ignition on. Using backprobe set, measure voltage between PCM 32-pin connector "A" terminals No. 10 (Black wire) and No. 11 (Yellow/Black wire), and between No. 10 (Black wire) and No. 24 (Yellow/Black wire). If battery voltage exists, go to step  7. If battery voltage does not exist, repair open in Yellow/Black wire between PCM 32-pin connector "A" terminal No. 11 or No. 24 and PGM-FI main relay. See WIRING DIAGRAMS article. If wires are okay, replace PGM-FI main relay.
  7. Turn ignition off. Using backprobe set, measure voltage between PCM 32-pin connector "A" terminals No. 10 (Black wire) and No. 16 (Green/Orange wire). 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. See SUBSTITUTING PCM in SELF-DIAGNOSTICS - INTRODUCTION article. If symptom or indication goes away, replace original PCM.
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