Error Code P1299 is defined as Cylinder Head Temperature Sensor Detected Engine Overheating Condition. This means there’s an overheat condition, which is caused by multiple factors, such as a faulty thermostat, and low engine coolant.

This error code is a manufacturer-specific trouble code, meaning it does not apply to all vehicles equipped with OBD-II system or vehicles made since 1996 up to present. Rather, it applies to select manufacturers, such as Ford and Lincoln. Specifications on the definition, troubleshooting, and repairs still vary from one manufacturer to another.


The Engine Coolant Temperature Gauge works by obviously, indicating 1drivers the engine coolant temperature. For normal operating temperature, the needle will be in the normal range. If the needle enters the red section that means the engine is starting to overheat.

Common Symptoms

As with other codes, this P1299 activates the Check Engine light and registers the error code. It doesn’t usually come with drivability issues.

Possible Causes

There are many possible causes for this error code to arise. Some of the most common causes are:

  • Defective thermostat
  • Low engine coolant
  • Defective cylinder head temperature sensor
  • Open or shorted cylinder head temperature sensor
  • Poor electrical connection in the cylinder head temperature sensor circuit

How to Check

If you notice the needle entering the red section of the temperature gauge, stop the vehicle as soon as possible and switch off the engine to let it cool down.

If the needle enters the red section and the Check Engine light is activated on the dashboard, then refer to your How Fail Safe Cooling Works in Coolant from your Maintenance guide book.

How to Fix

Repairs for this code are pretty easy and straightforward, which could only be made possible by a thorough diagnosis of course. Some of the possible fixes are:

  • Thermostat replacement
  • Refilling of engine coolant
  • Replacement of cylinder head temperature sensor
  • Repair or replacement of open or shorted cylinder head temperature sensor
  • Repair or replacement of poor electrical connection in cylinder head temperature sensor

Though in many cases this code does not show drivability problems, it is important to have overheat condition to be fixed the soonest time possible, as it may dramatically increase the chance of engine damage. Make sure you take your vehicle to service facility as soon as possible.