I posted a bit ago about my gf's 91 Camaro 3.1L V6 and the concerns I had about her coolant temp sensor not turning the fan on. She had failed the emisions test and I'd known about it's tendancy to run a little hot in traffic so I started to check it out. I found out that the temp sensor is the only input to the ECM and it justifies if it's too hot and to turn the fan on. I put a decade resistance box in, in place of the temp sensor and found that I could turn the fan on and off. On at about 130 ohms and back off at about 220 ohms. From what I've read, that equates to about 240 degrees F. That's too darn hot. I verified the dash gauge with a thermometer in the radiator neck and they are fairly close. I also viewed the error codes and they were a 14 and a 15 which are temp sensor too high and temp sensor too low. I unplugged the ECM fuse for several minutes and when I jumpered the diagnostic plug, without even running the engine I get the same errors. Anybody got any hints, clues or ideas? Anybody ever try hooking up a laptop to the data signal and see if they can communicate with the OBD1? Thanks all for your time.