I have a 99 Z3 with the same codes. I did some research and figured it is a water temperature sensor by the radiator return hose. I checked it with an ohm meter hot and cold and it stayed at about 16 ohms. It should be changing value as the temperature goes up.

to find it look about 2 inches behind the top of the fan blade. It has a little metal clip that you push in on and the connector lifts up to reveal it has two contacts.

5 volts from the ECU goes in the one contact and about 0 to 5 volts should return to the ECU depending on how warm the engine is.

This value is used by the ECU to make the fuel injector pulse width greater when the engine is cold.

When this fault is detected the ECU it automatically uses the oil temp sensor located behind the oil filter canister.

Be careful when buying the replacement part because you will always find the oil temp sensor called water/oil temp sensor.

I can't find it myself and guess I will have to go the BMW dealer.

• Engine light - z3lover 2006-03-06 22:05:07 (1374 views)
  • Re: Engine light - petermerfo 2008-03-22 13:00:42 (160 views)
  • Re: Engine light - petermerfo 2008-03-15 14:53:52 (134 views)