Hi guys,

I'm wondering if anyone else has had this issue and has a permanent fix.

My engine temp sending unit randomly reports an invalid value, causing the computer to drive the gauge all the way to the "cold" position when the engine is at operting temp.

After a few incidences, this throws a "temp out of range" DTC code. Dealer replaced the sending unit at about 30K miles under warranty. Now at 34K miles, it's doing it again. I'm now wondering if the original sending unit was bad or if the dealer mis-diagnosed. Not sure what else would cause this besides a bad ECM/PCM or wiring/connector issue.

Has anyone had this issue that was fixed without replacing the sending unit (coolant temp sensor on top of engine)??

 

What was the code number it threw?


You can check out the gauge by performing the "Actuator Test".
Do this when you are getting an erroneous reading. If it passes, you can eliminate the gauge.



ACTUATOR TEST
The instrument cluster actuator test will put the instrument cluster into its self-diagnostic mode. In this mode the instrument cluster can perform a self-diagnostic test that will confirm that the instrument cluster circuitry, the gauges and the indicators are capable of operating as designed. During the actuator test the instrument cluster circuitry will position each of the gauge needles at various calibration points, illuminate each of the segments in the Vacuum-Fluorescent Display (VFD) units, and turn all of the indicators ON and OFF again.

Successful completion of the actuator test will confirm that the instrument cluster is operational. However, there may still be a problem with the CAN or LIN data bus, the Powertrain Control Module (PCM), the Totally Integrated Power Module (TIPM), the Controller Antilock Brake (CAB), the All-Wheel Drive Control Module (AWDCM), the Occupant Restraint Controller (ORC), the compass module, the Sentry Key REmote Entry Module (SKREEM) (also known as the Wireless Control Module/WCM), or the inputs to one of these electronic control modules. Use a diagnostic scan tool to diagnose these components. Refer to the appropriate diagnostic information.


1. Begin the test with the ignition switch in the OFF position.
2. Depress the odometer/trip odometer switch button.
3. While still holding the odometer/trip odometer switch button depressed, turn the ignition switch to the ON position, but do not start the engine.
4. Release the odometer/trip odometer switch button.
5. The instrument cluster will simultaneously begin to illuminate all of the operational segments in the VFD units, and perform a bulb check of each operational LED indicator. The VFD segments and LED indicators remain illuminated as each gauge needle is swept to several calibration points and back. If a VFD segment or an LED indicator fails to illuminate, or if a gauge needle fails to sweep through the calibration points and back during this test, the instrument cluster must be replaced.
6. The actuator test is now completed. The instrument cluster will automatically exit the self-diagnostic mode and return to normal operation at the completion of the test. The actuator test will be aborted if the ignition switch is turned to the OFF position, or if an electronic vehicle speed message indicating that the vehicle is moving is received over the CAN data bus during the test.
7. Go back to STEP 1 to repeat the test, if necessary.

 

my temp gauge went to cold once while I was driving.... the entire engine was submerged under water tho...

hasnt happened since.. you werent doing any extreme water crossings were you?

 

Thanks for the input, but the gauge is working properly. I don't have the DTC code values at the moment, but they indicated that the temperature reading (from the sensor) was out of range. When this happens, the PCM sends signal to the gauge to display full-on "Cold" and the cooling fan goes to max as a precaution (since the PCM doesn't know what the actual engine temp is).

This has happened on and off multiple times. Once I cycle the ignition, the problem goes away, gauge and fan go back to normal again...until the next time.

 

No, haven't done any water crossings, etc. Thanks for the input, though. Moisture or corrosion in the connectors could be a possible cause, I guess.