Interestingly enough, when it gets cold, my temp guage stops working (i.e. reads the lowest possible temp). It's clearly not a case of the engine not heating up. I've got plenty of heat coming out of the vents, the thermostat housing and the upper rad hose are plenty hot, so the engine is definitely warm. This only happens if the truck is parked outside overnight :-).

Anyone else have this happen?

Chris.

 

Mine has the same problem. It would work on occasion, but if it sat overnight it typically would not work. The dealership tried to zap the computer but that did not work. It took them 2 days to figure that out. Now, they are going to replace the entire dash component. It has to be sent somewhere to have the current mileage programed into the odometer (603 miles). I took it in Dec. 3rd and still do not have it back. Tomorrow will be 2 weeks...

 

If the instrument cluster fails to receive an engine temperature message, it will hold the gauge needle at the last indication for about five seconds or until the ignition switch is turned to the OFF position, whichever occurs first. After five seconds, the cluster will move the gauge needle to the low end of the gauge scale. If yours is at the low end, the cluster has a good chance of being OK, otherwise, it may be off scale.

When it is not reading correctly, try wiggling the wires at the temp sensor while someone watches the gauge.
An actuator test of the instrument cluster might be in order.

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.

 

Wow! THat's pretty high tech compared to my old YJ :-). Thanks. I'll give that a try tonight.

Chris.

 

I had an old '89 Nissan truck (4X2) once and this happened a couple times..they said it was the thermostat. That was one tough truck btw. Do not know if that helps.

 

Not to hijack the thread, but I've been having the same sort of trouble with the gas gauge, when cold (below 35) it reads "E", I've had it to the dealer for other warranty work 3 times, and ask them to fix it, each time I go, it works I guess I'll have to leave it over night when it's cold.

 

Yeah, that's what I expect the dealership to say.

It's definitely not the thermostat though. That's why I checked the temperature of the upper rad hose and the thermostat housing. Since it's hot, then both the engine is hot, and the t-stat would have opened recently showing that it's not stuck closed. If it had been stuck open, I'd have low heat from the heaters and generally a not very hot upper rad hose.

Anyway, the temp guage should take the temperature from the engine side of the thermostat, so if all was well, even with a bad t-stat, it should show some movement of the needle. I'm going to try that diagnostic test in an hour or so.

My jeep has a few other intersting electrical issues, so I expect that this is more of the same :-).

I find that if I don't do sufficient diagnosis for myself, then I get crummy service from the dealership. Both the Chysler dealership and the GMC one where I used to take my pickup had the following method of making repairs:

- clear all codes.
- tell me to let them know if it happens again.

:-)

Chris.

 

Yep mine went in today for a new cluster, the temp gauge did'nt like to work all the time. The told me that it should be done by thursday afternoon at the latest, they would have a new cluster shiped in overnight. Hope so, they gave me a little rental car and it is going to snow thursday and friday and the Jeep goes alot better in the snow and ice...

 

Hi all,

I did the diagnostic test last night and it indicated that all is working as it should. (pretty entertaining test actually ) I'll have a look at the connection on the sensor next.

thanks,

Chris.

 

Did you perform the test when the gauge is known to be not working (as when cold)?