Code 15 Troubles
Thread Starter
Instructor
Joined: Jan 2007
Posts: 163
Likes: 1
From: Reedley, USA California
Code 15 Troubles
Alright so my car is reading a code 15 - coolant sensor circuit low. It's a 1993 LT1
Digital reads 142 degrees (I know, that's an impossible temp to be running at) continuously despite temperature changes reflected by the analogue temp. When temp does change, it shows something impossibly low like 60 degrees and the car loses power. "Service Engine Soon" light also is on.
The primary fan is always running, even with a cold start.
Replaced the temp sensor, the thermostat, and wiring is all good and grounds. Has 5 volts to the temp sensor connector. Problem still prevails.
Been trying various resistors in place of temp sensor. Tried one that made the temp continuously read at 197. Car barely starts when cold with that resistor as the oil temp and engine temp are confusing it too much - But when the car is warm and both temps seem right to the ECM, car runs great and shows no codes. And service engine light is off. With a resistor that would read a low temp (around 60 degrees), and the car warm, it does not start. Tomorrow, we'll be trying that resistor when the car is cold to see how it starts.
My dad and I are pretty stumped. What is wrong with my car?!
Digital reads 142 degrees (I know, that's an impossible temp to be running at) continuously despite temperature changes reflected by the analogue temp. When temp does change, it shows something impossibly low like 60 degrees and the car loses power. "Service Engine Soon" light also is on.
The primary fan is always running, even with a cold start.
Replaced the temp sensor, the thermostat, and wiring is all good and grounds. Has 5 volts to the temp sensor connector. Problem still prevails.
Been trying various resistors in place of temp sensor. Tried one that made the temp continuously read at 197. Car barely starts when cold with that resistor as the oil temp and engine temp are confusing it too much - But when the car is warm and both temps seem right to the ECM, car runs great and shows no codes. And service engine light is off. With a resistor that would read a low temp (around 60 degrees), and the car warm, it does not start. Tomorrow, we'll be trying that resistor when the car is cold to see how it starts.
My dad and I are pretty stumped. What is wrong with my car?!
Last edited by TRace8893; Nov 17, 2009 at 09:07 PM.
