86 C4 Troubleshooting error code 15
Thread Starter
1st Gear
Joined: Mar 2009
Posts: 1
Likes: 0
86 C4 Troubleshooting error code 15
My 86 is throwing a code 15 error message. A quick look shows this to be an error with the coolant temp sensor. The issue is, I have changed the temp sensor and upgraded the wiring connector to the appropriate plug, and I still can't chase down this error code. The service engine light stays on and is effecting the performance of my car and actually stops me from cranking at times. I've also put in a new fan temp switch. Several hours under the hood and on the net have proven fruitless. Any ideas?
Eric
Eric
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
If you have the field service manual, follow the diagnostic tests. With a new sensor and harness plug, I would suspect the wiring from the plug to the ECM. You can check this with an ohmeter.
Team Owner
Joined: Jan 2003
Posts: 20,315
Likes: 245
From: Summerland B.C. Canada
You should be able to track down the reason for a code 15. I had it once and I know how crappy it can make your motor run. 
Follow the tree in here http://members.shaw.ca/corvette86/Code%2015.pdf
Follow the tree in here http://members.shaw.ca/corvette86/Code%2015.pdf
