My car was originally never equipped with fog lamps from the factory. When I swapped out my stock front end for the GXP front end I had to find a way to make the fog lamps work. I used a factory fwd lamp harness for w/ fog applications to wire up the front portion of the fogs. When doing so I found that the harness I used had a different connector for the ambient temp sensor. Rather than going through the hassle of swapping the pigtails i bough a new sensor to fit the new harness for $5 and put it in. Here is my problem... since I did this my temp display is about 20 degrees under the real temp. I have searched my owners manual and talked to some GM dealer techs and have not been able to figure out how to reset the reading. Any of you fine people know how to reset the sensor?
There is no reset. The sensor is a simple thermistor...it's resistance changes with changes in temp. You have somehow changed the circuit. Unsure if reversing the wires would produce that symptom.
This is how it works:
The air temperature sensors are a 2-wire negative temperature co-efficient thermistor. The vehicle uses the following air temperature sensors:
• Ambient air temperature sensor
• Upper air temperature sensor
• Lower air temperature sensor
A signal and low reference circuit enables the sensor to operate. As the air temperature surrounding the sensor increases, the sensor resistance decreases. The sensor signal voltage decreases as the resistance decreases. The sensor operates within a temperature range between -40 to +101°C (-40 to +215°F). The sensor signal varies between 0-5 volts. The input of the duct air temperature sensors are different from the ambient and inside air temperature sensors. The HVAC control module converts the signal to a range between 0-255 counts. As the air temperature increases the count value will decrease.
You might consider reverting back to the original sensor by however means. I really can't imagine why there would be two different sensors for your car so I'm thinking the new one is simply the wrong part.
Yeah.. I think that may be a better solution. I still have the old harness so I'll just transfer the pigtail from the old to new and put the old sensor back in. Thanks for the help.
It's been a long time coming but I finally got around to switching the pigtails and reinstalling the original sensor. Worked like a charm I once again have an accurate temp gauge. Thanks greenman :thumbup:
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