well its a f22a1 turbo w/a p28 s300 and it throws a cel and then the temp gauge raises???? when it does i check the over flow and the coolant its boiling or that hot. i changed fan sensors, temp gauge sensor, water pump, timing belt, no thermostat, fans work, and the temp goes up and down when im driving. the cel goes off when i try to get a code but turns back on when i take out the jumper. then when i turn off my car and back on the cel light goes off.

 

When pulling the code, are you inserting the jumper and then turning the ignition to the ON position? If done correctly, when you turn the ignition to the ON position, you should see are series of flashes from your CEL.

Check all your hoses and connections, a small leak or irregularity in pressure can cause this.

 

well when i turn it off the light isnt there. im thinking its the radiator im sure its not leaking cause the radiator is always full but ill pressure check it. thanks for the reply