Originally Posted by bobs
FYI, these are normally resistance devices, so if the temperature is reading off, check for corrosion on the wiring harness connectors. Usually plugging/unplugging them a few times is enough to clean them off enough to make them read right again.
Good call!
A temperature sensor is referred to us EE types as an RTC sensor (reverse temperature co-efficient). That means that as their temperature goes up, their resistance goes down.
Error:
If the
reading is low there is
too much resistance, additional resistance in the circuit can be caused by corrosion in the sensor wiring (that would explain the -36 degree reading).
If the
reading is high there is
too little resistance, more likely a failure in the detection module, or a short circuit in the sensor wiring.
Don't overlook the entire circuit wiring, including the wiring inside the vehicle. The
ambient temperature sensor is routed directly to the instrument cluster; connector 2 pins 5 & 6.