1501

UnclassifiedCooling

What This Code Means

RPM Sensor Loss; Engine cranks but will not start; Unit turns over but will not start; Overspeed; Low oil pressure; High temperature; Twin Cylinder Running faults; Twin Cylinder Cranking faults; Unit is Overloaded; Engine speed slowing; Prolonged Under-Voltage; Instantaneous Undervoltage; Shutdown Alarm/ Fault Occurred During Crank Attempt, Start or Run; NO CRANK; Wiring Continuity Issue (Wire 18); LOW OIL PRESSURE; HIGH OIL TEMPERATURE; OVERCRANK; LOW BATTERY; IGNITION SPARK ISSUE; SHUTDOWN WIRE ISSUE; OVERSPEED; RPM SENSE LOSS; CRANK; NO CRANK CODE; RUNNING E-CODE; LOW OIL PRESSURE E-CODE; HIGH TEMP E-CODE; OVERCRANK E-CODE; OVERSPEED E-CODE; RPM SENSE LOSS E-CODE; CRANK E-CODE; Engine shutdown; Loss of engine ignition; Fuel shutoff solenoid closure; Engine shutdown and latch out; Engine re-cranks

Possible Causes

  • •Air flow impeded / flow issue
  • •Air pocket in fuel line
  • •BAD
  • •BAD NO SIGNAL
  • •Board does not see a valid RPM signal within 3 seconds during cranking
  • •Closure of the fuel shutoff solenoid
  • •Controller does not see an RPM signal (will not energize Wire 14/Fuel Solenoid)
  • •Controller is receiving signal on Wire 18
  • •Defective circuit board
  • •Dirty fuel
  • •Faulty crank circuit
  • •Faulty starter
  • •Fuel supply low
  • •Grounding of the ignition circuit
  • •Loss of voltage for some time (10+ seconds)
  • •Missing ignition pulse (loss of one of the primary coils)
  • •NO SIGNAL
  • •Occurred while running
  • •RPM signal lost for one full second during running
  • •SHORTED WIRE 18 OR CIRCUIT BOARD
  • •Shorted Wire 18
  • •Shorted wire 18 or circuit board
  • •Starter motor issue
  • •Stepper motor/mixer body assembly issue
  • •Sudden loss of voltage
  • •Temperature exceeds approximately 293 ºF (144 ºC)
  • •Throttle control problem
  • •Unit is Overloaded
  • •Wire 18 continuity fault

Suggested Actions

  1. 1CHECK INSTALLATION FOR PROPER AIRFLOW
  2. 2Check oil level and pressure
  3. 3Check the inlet/outlet for debris
  4. 4Clear any faults in the controller before proceeding with any running diagnostic steps
  5. 5Clear any faults in the controller before proceeding with diagnostic steps
  6. 6Go to Problem 16
  7. 7Go to Problem 17
  8. 8If engine cranks, Test 64
  9. 9If engine does not crank, Problem 15
  10. 10Perform Test 50
  11. 11Perform Test 64
  12. 12Preliminary Output Voltage Test (firmware v1.01 ( Oevo ) and above)
  13. 13Preliminary Output Voltage Test (firmware v1.01 (Oevo)
  14. 14Problem 17
  15. 15Problem 3
  16. 16Proceed to Problem 16
  17. 17REPAIR OR REPLACE DEFECTIVE SWITCH
  18. 18REPAIR OR REPLACE SHORTED WIRE 18 OR CIRCUIT BOARD
  19. 19Repair or replace shorted Wire 18 or circuit board
  20. 20Repair or replace shorted wire 18 or circuit board
  21. 21TEST 61 – CHECK OIL PRESSURE SWITCH AND WIRE 86
  22. 22TEST 62 – CHECK HIGH OIL TEMPERATURE SWITCH
  23. 23TEST 64 – CHECK WIRE 18 CONTINUITY
  24. 24Test 12
  25. 25Test 50
  26. 26Test 61
  27. 27Test 62
  28. 28Test 64
  29. 29Test 64 – Check Wire 18 continuity
  30. 30Test 64 – Check wire 18 continuity
  31. 31Update controller to latest firmware

ASK RUDY ABOUT THIS FAULT

Get a diagnosis walkthrough for 1501 on your specific Generac unit — cited to the OEM manual, not a forum guess.

GET THE ANSWER

Free account required — we'll bring your question with you.