Ford CSG-6491 Engine

• Engine will not crank.
  Cause: Fault lamp on
  Fix: Correct fault and reset control
• Engine will not crank
  Cause: Fault lamp on
  Fix: Correct fault and reset control
• PRE LO OIL PRES lamp lights. Engine continues to operate. PRE LO OIL PRES
  Fix: Indicates engine oil pressure has dropped to 20 psi (138 kPa). If engine can be stopped, follow procedures in step 5. If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow step 5 procedure.
• PRE HI ENGINE TEMP lamp lights. Engine continues to operate. PRE HI ENGINE TEMP
  Fix: Indicates engine has begun to overheat and engine temperature has risen to approximately 205°F (97°C). If engine can be stopped, follow the procedures in step 3. Use the following procedures if generator is powering critical loads and cannot be shut down. a. Check air inlets and outlets and remove any obstructions to airflow. b. Open doors or windows in generator area to increase ventilation. c. Reduce load if possible by turning off non-critical loads.
• LO OIL PRES lamp lights. Engine shuts down. LO OIL PRES
  Fix: Indicates engine oil pressure has dropped to 14 psi (97 kPa). Check oil level and replenish if low. Reset control and restart. Contact an Onan dealer or distributor if oil pressure is not in the range of 35 to 60 psi (241 to 414 kPa) ...
• HIGH ENG TEMP lamp lights. Engine shuts down. HIGH ENG TEMP
  Fix: Indicates engine has overheated and engine temperature has risen above 215°F (102°C) or coolant level is low (sets with coolant level sensor). Allow engine to cool down completely before proceeding with the following checks: a. Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. b. Check for obstructions to cooling airflow and correct as necessary. c. Check for a slipping fan belt and tighten if loose. d Reset control and restart after locating and correcting problem. Contact an Onan dealer or distributor if none of the above.
• Fault lamp lights but no fault exists. Engine gauges show oil pressure, engine temperature and frequency (speed) are within normal limits. FAULT
  Fix: Reset control. If control will not reset, the monitor board or a sensor may be at fault. Contact an Onan dealer or distributor for service.
• The standard undesignated fault functions are lights; Engine shuts down immediately, programed to shut down the set when a fault is sensed. Fault 1 is time-delayed while Fault 2 is immediate. FAULT 1 or FAULT 2
• The FAULT 1 or FAULT 2 fault lamp lights; Engine shuts down immediately, engine runs for several seconds and then shuts down, or engine continues to run.
  Cause: The standard undesignated fault functions are programmed to shut down the set when a fault is sensed. Fault 1 is time-delayed while Fault 2 is immediate. The nature of the fault is an optional selection that is determined when the set installation is designed. The undesignated fault functions may also be programmed for non-shutdown or non-time delay modes.
• SWITCH OFF lamp flashes.
  Cause: Indicates Run/Stop/Remote switch is in the STOP position which will prevent automatic starting if an automatic transfer switch is used
  Fix: Move the Run/Stop/Remote switch to the REMOTE position for automatic starting
• SWITCH OFF lamp flashes
  Cause: Run/Stop/Remote switch is in the STOP position which will prevent automatic starting if an automatic transfer switch is used
  Fix: Move the Run/Stop/Remote switch to the REMOTE position for automatic starting
• OVERCRANK lamp lights and engine stops cranking.
  Cause: Possible fuel or ignition system problem; Empty fuel tank, fuel leaks, or plugged fuel lines; Dirty fuel filter; Dirty or plugged air filter; Loose connections in the ignition primary, ignition secondary, or solenoid valve circuits
  Fix: Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required; Check for dirty fuel filter and replace if necessary (see Maintenance section); Check for dirty or plugged air filter and replace if necessary (see Maintenance section); Check for loose connections in the ignition primary, ignition secondary, or solenoid valve circuits and correct as required; Reset the control and restart after correcting the problem. Contact an Onan dealer or distributor for service if none of the above; Check choke adjustment for dual-fuel system
• OVERCRANK lamp lights and engine stops cranking
  Cause: Possible fuel or ignition system problem
  Fix: Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required; check for dirty fuel filter and replace if necessary (see Maintenance section); check for dirty or plugged air filter and replace if necessary (see Maintenance section); check for loose connections in the ignition primary, ignition secondary, or solenoid valve circuits and correct as required; reset the control and restart after correcting the problem; contact an Onan dealer or distributor for service if none of the above
• No AC output voltage.
  Cause: Field breaker is tripped
  Fix: Reset breaker. Contact an Onan dealer or distributor if voltage buildup causes breaker to trip
• LO FUEL lamp lights. Engine shuts down and LO OIL PRES lamp lights.
  Cause: Indicates engine has run out of fuel
  Fix: Check fuel level and replenish as required

Compiled from service & troubleshooting documentation across every generator set that uses the Ford CSG-6491.

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.