2003 Eddie Bauer 4.6L P1299 Code and reduced power mode.

[bandhippie]

I got a code P1299 which put the car in a lower power mode.

The temperature gauge is pegged at high, even when just starting the vehicle after leaving overnight.

If the CHT sensor is unplugged the car will not throw any codes and run normal.

When putting an ohmmeter on the temp sensor, it reads out the correct resistance for the temperature at all ranges.

The wire to the temp sensor measures 4.8 volts with the car running, and 4.79 volts with key on engine off.

I am just looking for what other things I can test to determine what is wrong with my car, or a good repair manual that can guide me to a solution.

 

[bandhippie]

So I figured out the problem.

The intake manifold was leaking and sprayed coolant on the connector for CHT sensor. This caused a short which made the sensor read as if really hot. The sensor and the short connector had to be replaced, as well as a new intake manifold. The leak was due to a crack in the manifold where the gasket sits.

 

[imp]

So I figured out the problem.

The intake manifold was leaking and sprayed coolant on the connector for CHT sensor. This caused a short which made the sensor read as if really hot. The sensor and the short connector had to be replaced, as well as a new intake manifold. The leak was due to a crack in the manifold where the gasket sits.

@bandhippie Good detective work!