HIGH ENGINE TEMPERATURE

Possible Causes

• •Active shutdown fault (High Engine Temperature, Low Oil Pressure, Overcrank, or Overspeed)
• •Battery connected incorrectly or abnormal voltage
• •Blown fuse F1
• •Defective Engine Monitor module J5
• •Defective R-S-R switch S15
• •Defective starter
• •Dirty K12 relay contacts or defective K12 relay
• •Dirty K14 relay contacts or defective K14 relay
• •Dirty ignition relay K12 socket connection or open K12 coil
• •Engine speed reaches approximately 2100 r/min (overspeed condition)
• •Engine temperature reaches 215°F (102°C)
• •Failure to start after the 75-second cranking period
• •Faulty Engine Monitor board J5
• •High Engine Temperature shutdown
• •Ignition relay K12 fails to energize
• •Incorrect battery connection or abnormal voltage
• •Low engine temperature
• •Oil pressure drops to 14 psi (97 kPa)
• •Open K12 ignition relay coil or dirty K12 relay socket connection
• •Open-circuit starter coil or poor wiring between TB11 terminal 22 and starter
• •Start solenoid K13 fails to energize

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 & 7 and check wiring, or replace K14 if necessary (See Test Procedure [D])
7. 7Clean K14 relay contacts 1 h 7, check wiring, and replace K14 if necessary (See Test Procedure [D])
8. 8Clean ignition relay K12 socket connection or replace K12
9. 9Clean relay K12 socket connection
10. 10Jumper B+ at center terminal of R-S-R switch to terminal B of K12, check if engine cranks, and replace Engine Monitor module J5 (See Test Procedure [J])
11. 11Measure B+ voltage at starter coil terminal (See Test Procedure [C])
12. 12Perform High Engine Temperature fault checks (See block 1 on page 20)
13. 13Perform Low Oil Pressure fault checks (See block 2 on page 20)
14. 14Perform Overcrank fault checks (See block 3 on page 20)
15. 15Perform Overspeed fault checks (See block 4 on page 20)
16. 16Perform jumper test (jumper B+ at center terminal of R-S-R switch to terminal B of K12) and see Test Procedure [J]
17. 17Remove jumper and replace Engine Monitor module J5
18. 18Replace Engine Monitor module J5
19. 19Replace defective R-S-R switch S15
20. 20Replace starter
21. 21Verify battery connection and voltage (See Test Procedure [B])

Related Onan Fault Codes