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Overhead Console-DIFFERENT ISSUE Reads -40
i know there are hundreds of threads about the overhead console. But, they do not address my issue. The two I did find had no resolution.
My issue is the my ambient temperature is always at -40. I have removed the sensor behind the grill and nothing changes. I have pulled the circuit board down and fixed the resistor the came unsoldered and checked all the rest.
Caret1>AMBIENT TEMPERATURE SENSOR
The thermometer function is supported by the ambient temperature sensor, a wiring circuit, and a portion of the compass mini-trip computer module. If any portion of the ambient temperature sensor circuit fails, the compass/thermometer display function will self-diagnose the circuit. If 55° C (131° F) appears in the display, the sensor is being exposed to temperatures above 55° C (131° F), or the sensor circuit is shorted. If –40° C (–40° F) appears in the display, the sensor is being exposed to temperatures below –40° C (–40° F), or the sensor circuit is open.
The ambient temperature sensor circuit can also be diagnosed using the following Sensor Test, and Sensor Circuit Test.
Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Disconnect the ambient temperature sensor wire harness connector.
Measure the resistance of the ambient temperature sensor. At –40° C (–40° F), the sensor resistance is 336 kilohms. At 55° C (131° F), the sensor resistance is 2.488 kilohms. The sensor resistance should read between these two values.
SENSOR CIRCUIT TEST
Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Disconnect the ambient temperature sensor wire harness connector and the overhead console wire harness connector.
Connect a jumper wire between the two terminals in the body half of the ambient temperature sensor wire harness connector.
Check for continuity between the sensor return circuit and the ambient temperature sensor signal circuit cavities of the roof wire harness overhead console connector. There should be continuity. If OK, go to Step 4. If not OK, repair the open sensor return circuit or ambient temperature sensor signal circuit to the ambient temperature sensor as required.
Remove the jumper wire from the body half of the ambient temperature sensor wire harness connector. Check for continuity between the sensor return circuit cavity of the roof wire harness overhead console connector and a good ground. There should be no continuity. If OK, go to Step 5. If not OK, repair the shorted sensor return circuit as required.
Check for continuity between the ambient temperature sensor signal circuit cavity of the roof wire harness overhead console connector and a good ground. There should be no continuity. If OK, refer to Compass Mini-Trip Computer in the Diagnosis and Testing section of this group. If not OK, repair the shorted ambient temperature sensor signal circuit as required.
EDIT: Mine was exactly as the above resolution described. I pulled the four top screws off the grill and removed the temperature sensor. I unclipped it from the radiator support and then went under in the fender well and unscrewed the bolt that was pointing up at the very front of the fender well.
Once the fender well dropped down, I could see the wires from the temp sensor had another plug just in front of the fender well, still on the radiator support in front of the tire. I unplugged the connector and unclipped the other four or five clips that held the wires to the radiator support.
The wires are only about 16" long, but they have a lot of clips holding it in place.
Once I had the wires out, I checked the continuity on them. Sure enough, one of them was bad. As I pulled the outer jacket off the wires I noticed about 4" back that one of the wires had been smashed and all that was holding it together was a small piece of the plastic jacket.
Nothing else around was damaged. My guess is this was done during assembly or even earlier and most likely never worked. I fixed the wire and sure enough the temperature works fine.
The previous owner told me he had it looked at a number of times, but the dealer could never find the problem. My guess is they really did not put too much effort into looking for a cut wire in all that mess of wires.
So, if you have this issue, I suggest you start at one end and take it section by section to see where the break is. If it is in too hard of a place to fix, just run another wire from where you do have power to the furthest place you know you have continuity to the sensor.
I actually figured I would have to end up running a new wire, but I got lucky.
Best of luck.
Any ideas or thoughts would be appreciated.
Last edited by 6.0 Hauler; 04-20-2017 at 02:34 PM.