Onan

F1

UnclassifiedCooling

What This Code Means

Engine fails to crank with switch in RUN position; Engine fails to crank; High Engine Temperature shutdown fault lamp lights; Low Oil Pressure shutdown fault lamp lights; Overcrank shutdown fault lamp lights; Overspeed shutdown fault lamp lights; High Engine Temperature shutdown fault lamp is lit; Low Oil Pressure shutdown fault lamp is lit; Overcrank shutdown fault lamp is lit; Overspeed shutdown fault lamp is lit; Start solenoid K13 energizes but B+ voltage is not measured at starter coil terminal; Start solenoid K13 energizes, B+ voltage is measured at starter coil terminal, and B+ is measured at terminal 26 on TB11; Start solenoid K13 does not energize; Ignition relay K12 energizes; B+ voltage is not measured at center terminal 6 of R-S-R switch S15 when in Run position; B+ voltage is measured at center terminal 6 of R-S-R switch S15 and at 'B' terminal of K12; Relay K12 energizes and contacts 4 & 7 close; Relay K12 does not energize; B+ is measured at K14 terminal 1 but not at K13

Possible Causes

  • •Abnormal battery voltage
  • •Active shutdown fault (High Engine Temperature, Low Oil Pressure, Overcrank, or Overspeed)
  • •Battery connected incorrectly or abnormal voltage
  • •Defective Engine Monitor module J5
  • •Defective K12 relay
  • •Defective R-S-R switch S15
  • •Defective starter
  • •Dirty K12 relay contacts or defective K12 relay
  • •Dirty K14 relay contacts or defective K14 relay
  • •Faulty relay wiring
  • •Faulty wiring between TB11 terminal 22 and starter
  • •High Engine Temperature
  • •Incorrect battery connection
  • •Low Oil Pressure
  • •No B+ voltage measured at starter coil terminal when start solenoid K13 is energized
  • •Open K12 ignition relay coil or dirty K12 relay socket connection
  • •Open-circuit starter coil or poor wiring between TB11 terminal 22 and starter
  • •Overcrank condition
  • •Overspeed condition
  • •Relay K12 contacts dirty

Suggested Actions

  1. 1Check fuse F1
  2. 2Check if ignition relay K12 energizes (See Test Procedure [A])
  3. 3Check wiring between TB11 terminal 22 and starter
  4. 4Clean K12 relay contacts or replace K12 relay
  5. 5Clean K12 relay contacts or replace relay and check wiring (See Test Procedure [D])
  6. 6Clean K14 relay contacts 1 h 7, check wiring, and replace K14 if necessary (See Test Procedure [D])
  7. 7Clean relay K12 socket connection
  8. 8Jumper B+ at center terminal of R-S-R switch to terminal 'B' of K12 to test (See Test Procedure [J])
  9. 9Perform jumper test (jumper B+ at center terminal of R-S-R switch to terminal B of K12) and see Test Procedure [J]
  10. 10Remove jumper and replace Engine Monitor module J5
  11. 11Replace K12 relay
  12. 12Replace defective R-S-R switch S15
  13. 13Replace defective switch S15
  14. 14Replace starter
  15. 15See block ① on page 20
  16. 16See block ② on page 20
  17. 17See block ③ on page 20
  18. 18See block ④ on page 20
  19. 19Verify battery connection and check if voltage is normal (See Test Procedure [B])
  20. 20Verify battery connection and voltage (See Test Procedure [B])

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