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Home >> Acura >> 2002 >> 3.2CL Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Basic Diagnostic Procedures >> Fuel System >> PGM-FI Main Relay Circuit Testing >> MDX, 3.2CL & 3.2TL
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MDX, 3.2CL & 3.2TL

  1. Remove PGM-FI relay located under left side of instrument panel. Disconnect 7-pin PGM-FI main relay connector. See Figure .
  2. Test for continuity between ground PGM-FI main relay terminal No. 3. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire between PGM-FI relay terminal No. 3 and ground terminal G101. See WIRING DIAGRAMS article.
  3. Using voltmeter connected to ground, measure voltage at PGM-FI main relay terminal No. 7. If battery voltage exists, go to step  5 . If battery voltage does not exist, go to next step.
  4. Check for blown No. 46 ACG S (15-amp) fuse in under-hood fuse/relay box. If fuse is blown, repair short in White/Green wire between No. 46 ACG S (15-amp) fuse and PGM-FI main relay terminal No. 7. If fuse is not blown, repair open in White/Green wire between No. 46 ACG S (15-amp) fuse and PGM-FI main relay terminal No. 7.
  5. Turn ignition switch on. Using voltmeter connected to ground, measure voltage at PGM-FI main relay terminal No. 5. If battery voltage exists, go to step  7 . If battery voltage does not exist, go to next step.
  6. Check for blown No. 1 FUEL PUMP (15-amp) fuse in driver's under-dash fuse/relay box. If fuse is blown, repair short in Red/White wire between No. 1 FUEL PUMP (15-amp) fuse and PGM-FI main relay terminal No. 5. See WIRING DIAGRAMS article. If fuse is not blown, repair open Red/White wire between No. 1 FUEL PUMP (15-amp) fuse and PGM-FI main relay terminal No. 5.
  7. Push clutch pedal in or shift to park. Turn ignition switch to START position. Using voltmeter connected to ground, measure voltage at PGM-FI main relay terminal No. 2. If battery voltage exists, go to step  9 . If battery voltage does not exist, go to next step.
  8. Check for blown No. 13 STARTER SIGNAL (7.5-amp) fuse in driver's under-dash fuse/relay box. If fuse is blown, repair short in Blue/Orange wire between No. 13 STARTER SIGNAL (7.5-amp) fuse and PGM-FI main relay terminal No. 2. If fuse is not blown, repair open Blue/Orange wire between No. 13 STARTER SIGNAL (7.5-amp) fuse and PGM-FI main relay terminal No. 2.
  9. Turn ignition switch off. Disconnect ECM/PCM 32-pin harness connector "A". See Fig 1 . Go to next step.
    Fig 1: Identifying PCM Harness Connector Terminals (MDX, 3.2CL & 3.2TL)
    G00009610Courtesy of AMERICAN HONDA MOTOR CO., INC.
  10. Check for continuity between PGM-FI main relay terminal No. 1 and ECM/PCM terminal No. 15 (Green/Yellow wire). See WIRING DIAGRAMS article. If continuity is present, go to next step. If continuity is not present, repair open in Green/Yellow wire between PGM-FI main relay terminal No. 1 and ECM/PCM terminal No. 15.
  11. Reconnect ECM/PCM 32-pin harness connector "A" and PGM-FI main relay 7-pin harness connector. Go to next step.
  12. Turn ignition switch in. Measure voltage between ECM/PCM 25-pin harness connector terminals No. 1 (Yellow /Black wire) and 2 (Black wire), and between terminals No 9 (Yellow/Black wire) and 2 (Black wire). See Fig 1 . If battery voltage exists, go to next step. I battery voltage does not exist, check for an open in Yellow/Black wires between PGM-FI main relay terminal No. 6 and ECM/PCM terminals No. 1 and 9. If wires are okay, replace PGM-FI main relay.
  13. Turn ignition switch off, then on again and measure voltage within the first 2 seconds, between ECM/PCM 32-pin harness connector terminal No. 15 and ECM/PCM 25-pin harness connector terminal No. 2. If less than one volt exists, PGM-FI main relay may be faulty. Go to next step. If less than one volt does not exist, substitute a known-good ECM/PCM and recheck. If voltage is as specified, replace original ECM/PCM.
  14. Remove PGM-FI main relay.
  15. Connect power to PGM-FI main relay 7-pin harness connector terminal No. 2 and connect ground to PGM-FI main relay 7-pin harness connector terminal No. 1. Check for continuity between PGM-FI main relay terminals No. 5 (Red/White wire) and 4 (Black/Yellow wire). See Figure . If continuity is present, go to next step. If continuity is not present, replace PGM-FI main relay and retest.
    NOTE: Do not use terminal numbers molded into relay.
  16. Connect battery power to PGM-FI main relay 7-pin harness connector terminal No. 5 and connect ground to PGM-FI main relay 7-pin harness connector terminal No. 1. Check for continuity between PGM-FI main relay terminals No. 5 (Red/White wire) and 4 (Black/Yellow wire). See WIRING DIAGRAMS article. If continuity is present, PGM-FI main relay is okay. If continuity is not present, replace PGM-FI main relay and retest.
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