Fault code P1299 – a step-by-step guide to diagnosing and fixing it

Error code P1299 is displayed and the check engine light is on - what does this mean?

The DTC P1299 is a manufacturer-specific error code that mainly occurs in Ford vehicles and indicates a problem with the cylinder head temperature monitoring. The OBD system detects engine overheating or problems in the cooling system. This code can have different meanings for different manufacturers, which is why a precise diagnosis is required.

What causes can this error code have?

• Defective coolant temperature sensor
• Low coolant level or loss of coolant
• Clogged or defective radiator
• Defective water pump
• Thermostat jammed closed
• Damaged cables or plug connections in the cooling system
• Defective radiator fan or fan controller
• Blocked cooling ducts in the engine
• Defective cylinder head gasket
• Faulty engine control unit (ECU)

What symptoms occur in parallel with fault code P1299?

• Engine overheating: Temperature display shows excessive values
• Loss of power: Reduced engine power and poor acceleration
• Loss of coolant: Visible leaks under the vehicle
• Unsteady idling: Engine runs unstable at idle speed
• White smoke: Steam from the exhaust or under the hood
• Starting problems: Difficulty starting the engine after overheating
• Emergency running program: engine switches to protection mode

How can the problem with error code P1299 be rectified?

• The repair requires a systematic diagnosis of the cooling system and the associated sensors.
• Check and top up the coolant level, bleed the cooling system and test for leaks
• Test the coolant temperature sensor with a multimeter and replace if defective
• Remove thermostat, test in hot water and replace if faulty
• Check water pump for leaks and proper function, replace defective pump
• Check radiator for blockages, clean or replace if damaged
• Test radiator fan and fan control for correct function, replace defective components
• Check wiring harness and plug connections in the cooling system for damage and repair
• Check cylinder head gasket for leaks and have it professionally replaced if defective