So my girlfriend's car has been throwing the same code for a couple weeks now. Scanned and cleared the codes and the only one there was the coolant temp circuit.

 

Should I just replace the CTS or could this be a more sinister problem?

At what temperature is the car running?

Make sure the wiring is all good to go before you replace any switches. An unplugged sensor or a broken wire is a cheap fix.

So my girlfriend's car has been throwing the same code for a couple weeks now. Scanned and cleared the codes and the only one there was the coolant temp circuit.

 

Should I just replace the CTS or could this be a more sinister problem?

 

I would replace the sensor. It's not expensive and is a common thing to fail. I've had to do it on my 88RX, my 92Legacy, my 95 Legacy, and my 96Legacy. On the 88 and the 96 I was "lucky" enough to experience hot starting issues. When the sensor goes bad it can tell the ECU that the engine is cold when it is really warm. So if you drive the car for awhile and get it up to temp. Then shut it off for only a few minutes and try to start it again, with a bad sensor there is a chance it tells the ECU the engine is cold, which floods out the engine and makes it VERY hard to start.

 

Keith

Test the CTS with an ohm meter and measure the resistance in relation to the engines temp. Stone cold would be easiest so you know what temp it would be, and full operating temp around 190 degrees, with what value you are measuring against. I believe a haynes manual has the values for this test and you don't need to remove to sensor to do the the test. If the values are out of wack, replace the sensor.

Since you stated the circuit is bad then you need to check the connections to the sensor for a problem. It is pretty common for the connections at the sensor to get dirty.

Edited February 7, 200917 yr by Cougar

actually cougar, muffman mentioned broken wire, I would think that a broken wire would be unlikely.......But I think you were the one who called broken ground on my car when it had a cluster failure!

Whenever a code states there is a 'circuit' problem with a sensor, the wiring to that sensor needs to be checked first. There may be an open connection in one of the wires to the sensor, a short to ground or across the leads, possibly a highly resistive connection to the sensor, or some other wiring problem. The sensor itself is most likely ok and replacing it before the wiring is checked may be a needless expense. I my opinion the extra money would be better spent to help purchase a factory service manual.

Edited February 7, 200917 yr by Cougar