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PGM-FI Main Relay Circuit Troubleshooting

  1. Turn the ignition switch OFF.
  2. Disconnect the PGM-FI main relay 7P connector.
  3. Check for continuity between body ground and PGM-FI main relay 7P connector terminal No. 3.
    Fig 1: Checking For Continuity Between Body Ground & PGM-FI Main Relay 7P Connector Terminal No. 3
    G01464159Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  -Go to step 4.
    2. NO  -Repair open in the wire between the PGM-FI main relay and G101.
  4. Measure voltage between body ground and PGM-FI main relay 7P connector terminal No. 7.
    Fig 2: Measuring Voltage Between Body Ground & PGM-FI Main Relay 7P Connector Terminal No. 7
    G01464160Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES  -Go to step  6.
    2. NO  -Go to step 5.
  5. Check for a blown No. 46 ACGS (15A) fuse in the under-hood fuse/relay box.

    Is the fuse blown? 

    1. YES  -Repair short in the wire between the PGM-FI main relay and the No. 46 ACGS (15A) fuse.
    2. NO  -Repair open in the wire between the PGM-FI main relay and the No. 46 ACGS (15A) fuse.
  6. Turn the ignition switch ON (II), and measure voltage between body ground and PGM-FI main relay 7P connector terminal No. 5.
    Fig 3: Measuring Voltage Between Body Ground & PGM-FI Main Relay 7P Connector Terminal No. 5
    G01464161Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES  -Go to step  8.
    2. NO  -Go to step 7.
  7. Check for a blown No. 1 FUEL PUMP (15A) fuse in the driver's under-dash fuse/relay box.

    Is the fuse blown? 

    1. YES  -Repair short in the wire between the PGM-FI main relay and the No. 1 FUEL PUMP (15A) fuse.
    2. NO  -Repair open in the wire between the PGM-FI main relay and the No. 1 FUEL PUMP (15A) fuse.
  8. Shift to Park, then turn the ignition switch to the START (III) position, and measure voltage between body ground and PGM-FI main relay 7P connector terminal No. 2.
    Fig 4: Measuring Voltage Between Body Ground & PGM-FI Main Relay 7P Connector Terminal No. 2
    G01464162Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES  -Go to step  10.
    2. NO  -Go to step 9.
  9. Check for a blown No. 13 STARTER SIGNAL (7.5A) fuse in the driver's under-dash fuse/relay box.

    Is the fuse blown? 

    1. YES  -Repair short in the wire between the PGM-FI main relay and the No. 13 STARTER SIGNAL (7.5A) fuse.
    2. NO  -Repair open in the wire between the PGM-FI main relay and the No. 13 STARTER SIGNAL (7.5A) fuse.
  10. Turn the ignition switch OFF.
  11. Disconnect PCM connector A (32P).
  12. Check for continuity between PGM-FI main relay 7P connector terminal No. 1 and PCM connector terminal A 15.
    Fig 5: Checking For Continuity Between PGM-FI Main Relay 7P Connector Terminal No. 1 & PCM Connector Terminal A 15
    G01464163Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  -Go to step 13.
    2. NO  -Repair open in the wire between the PGM-FI main relay and the PCM (A15).
  13. Reconnect PCM connector A (32P) and the PGM-FI main relay 7P connector.
  14. Turn the ignition switch ON (II).
  15. Measure voltage between PCM connector terminals B1 and B2, and between B9 and B2.
    Fig 6: Measuring Voltage Between PCM Connector Terminals B1 & B2, & Between B9 & B2
    G01464164Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES  -Go to step 16.
    2. NO  -Check for an open in the wires between the PGM-FI main relay and the PCM (B1, B9). If the wires are OK, replace the PGM-FI main relay.
  16. Turn the ignition switch OFF, then ON (II) again.
  17. Measure voltage between PCM connector terminals A15 and B2 within 2 seconds after the ignition switch is turned ON (II).
    Fig 7: Measuring Voltage Between PCM Connector Terminals A15 & B2
    G01464165Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there 1.0 V or less? 

    1. YES  -The PGM-FI main relay may be faulty; go to step 18.
    2. NO  -Substitute a known-good PCM and recheck (see HOW TO SUBSTITUTE THE PCM FOR TESTING ). If prescribed voltage is now available, replace the original PCM.
  18. Remove the PGM-FI main relay.
    19. NOTE: Use the terminal numbers shown. Ignore the terminal numbers molded into the relay.
    Fig 8: Checking For Continuity Between PGM-FI Main Relay 7P Connector Terminals No. 5 & No 4
    G01464166Courtesy of AMERICAN HONDA MOTOR CO., INC.
  19. Connect battery power to PGM-FI main relay 7P connector terminal No. 2, and connect ground to PGM-FI main relay 7P connector terminal No. 1. Then check for continuity between PGM-FI main relay 7P connector terminals No. 5 and No 4.

    Is there continuity? 

    1. YES  -Go to step 20.
    2. NO  -Replace the PGM-FI main relay and retest.
  20. Connect battery power to PGM-FI main relay 7P connector terminal No. 5, and connect ground to PGM-FI main relay 7P connector terminal No. 3. Then check for continuity between PGM-FI main relay 7P connector terminals No. 7 and No. 6.

    Is there continuity? 

    1. YES  -Go to step 21.
    2. NO  -Replace the PGM-FI main relay and retest.
  21. Connect battery power to PGM-FI main relay 7P connector terminal No. 6, and connect ground to PGM-FI main relay 7P connector terminal No. 1. Then check for continuity between PGM-FI main relay 7P connector terminals No. 5 and No. 4.

Is there continuity? 

  1. YES  -The PGM-FI main relay is OK.
  2. NO  -Replace the PGM-FI main relay and retest.
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