Cylinder Head Over-Temperature Protection Active
2000-2003 Ford Excursion 7.3L V8 Power Stroke Diesel
Description
The PCM has activated the Fail-Safe Cooling (FSC) strategy because the Cylinder Head Temperature sensor detected dangerously high engine temperature. The PCM alternately disables fuel injectors to use cylinders as air pumps for cooling. The A/C is disabled, and the engine may enter limp mode or shut down entirely. This is a severe code — continued driving risks catastrophic engine damage including warped cylinder heads and blown head gaskets.
Symptoms
- Severe loss of power
- Engine running extremely rough (cylinders deactivated)
- A/C shuts off
- Temperature gauge pegged high
- Engine may stall and refuse to restart
- Limp mode activated
- Transmission may enter limp mode
Common Causes
- Low or no engine coolant
- Failed thermostat stuck closed
- Failed water pump
- Clogged or damaged radiator
- Failed cooling fan or fan relay
- Blown head gasket
- Faulty CHT sensor (false trigger)
- Exceeded towing or load capacity
- Damaged wiring to CHT sensor
Diagnostic Steps
- DO NOT continue driving — pull over safely
- Allow engine to cool completely
- Check coolant level (do NOT open cap when hot)
- Check for visible coolant leaks
- Verify cooling fans operate when engine is hot
- Test thermostat operation
- Pressure test cooling system
- Test CHT sensor resistance vs temperature chart
- Check for head gasket failure (exhaust gases in coolant)
Repair Notes
STOP DRIVING IMMEDIATELY. Allow engine to cool. Top off coolant if low. Diagnose and repair cooling system failure. If head gasket is blown, engine rebuild or replacement may be necessary. If CHT sensor is faulty, replace sensor.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1299 on Other Vehicles
Common Questions
What does code P1299 mean on a 2000-2003 Ford Excursion?
P1299 stands for "Cylinder Head Over-Temperature Protection Active". The PCM has activated the Fail-Safe Cooling (FSC) strategy because the Cylinder Head Temperature sensor detected dangerously high engine temperature. The PCM alternately disables fuel injectors to use cylinders as air pumps for cooling. The A/C is disabled, and the engine may enter limp mode or shut down entirely. This is a severe code — continued driving risks catastrophic engine damage including warped cylinder heads and blown head gaskets.
What are the symptoms of P1299 on a Ford Excursion?
Common symptoms of P1299 include: Severe loss of power, Engine running extremely rough (cylinders deactivated), A/C shuts off, Temperature gauge pegged high, Engine may stall and refuse to restart, Limp mode activated, Transmission may enter limp mode.
What causes P1299 on a 2000-2003 Ford Excursion?
Common causes of P1299 include: Low or no engine coolant, Failed thermostat stuck closed, Failed water pump, Clogged or damaged radiator, Failed cooling fan or fan relay, Blown head gasket, Faulty CHT sensor (false trigger), Exceeded towing or load capacity, Damaged wiring to CHT sensor.