check engine code 21

Ken92SVX · #1 06-26-2008, 06:07 PM

I am getting an intermittent check engine light for code #21, which I believe is for temperture sensor for the cooling system.

I can not get the search function to work.

What typicaaly causes a code #21?

Is it hard to replace the sensor and are there some pictures of where the sensor is located?

Thanks in advance!

Ken

Manarius · #2 06-26-2008, 07:42 PM

Code 21 is the Coolant Temperature Sensor. It's a small, about ~$25 sensor that is located under the Throttle Position sensor. It's on the driver's side near the back of the engine block on the top. It's easy to replace. It's a brown color and requires a deep socket 19mm to remove. Get the new one, quickly pull the old one, and replace. It's rather easy.

CorSVXette · #3 06-29-2008, 07:39 AM

Change that sensor soon! My light also came on and off and I didn't pay much attention to it until it came on and stayed on, then I had a hard time starting the car. Replaced the sensor and still had a hard time starting the car until I "CLEARED THE CODE". Make sure you clear that code after you replace the sensor.

Ken92SVX · #4 06-30-2008, 06:23 PM

Thanks for the replies.

I was going to get the part from Checker but it was the wrong part I believe. It was small, with a single snap on connector which is used for a gauge. Is there possibly 2 sensors to replace or just 1.

Is this a dealer only part?

Thanks, Ken

Hocrest · #5 06-30-2008, 06:30 PM

Yes there are 2 coolant sensors, they are right next to each other. Manarius had the description right for the one that sends the signal to the ECU. The one you got from Checker only has one wire and it feeds the signal for the dash gauge.

I think you can get them from most places, I know I got some from Rockauto.com, but I think the dealer price is real close or maybe lower than some aftermarket suppliers.