Hello,
     I have a 1989 Chevy Celebrity wagon. I know I know. But what the heck. I have been having problems with it starting from being left over night. Cold. So I decided to check the codes. It came back with 2 of them 15 + 21. I fixed code 21. That was the TPS. I replace that. Now on to the ECT. I replaced that sensor twice. But the code 15 keeps coming up. And thats the ECT. The ECT is Engine Coolant Temperature Sensor. Can someone tell me what the heck could it be. I mean 2 sensors and still the same problem. The code 15 says -- sensor indicates low temperature, or ECT open. I can't picture that I bought 2 brand new ECT's that where bad. But? I'm just lost here.

Thank you..   

Are you talking about the computer itself??