Ambient Temperature Sensor

The outside temperature function is supported by the ambient temperature sensor (ATS), a signal and ground circuit hardwired to the PCM, the BCM, and the CMTC display.

If the CMTC display indicates 60°C (140°F) or the ATS sense circuit is shorted to ground, the temp display will be 60°C (140°F) to indicate a SHORT circuit condition.

If the CTM display indicates -45°C (-49°F) or the ATS sense circuit is open, the temp display will be -45°C (-49°F) to indicate an OPEN circuit condition.

If there is an OPEN or SHORT circuit condition, it must be repaired before the CMTC VFD can be tested.

The ATS is supported by the PCM. ATS fault DTC's will be recorded in the PCM. The ATS can be diagnosed using the following Sensor Test. Test the ATS circuits using the diagnostics in this service information. If the ATS, the circuits, and PCI bus communications are confirmed to be OK, but the CMTC temperature display is inoperative or incorrect, replace the CMTC.