Hey guys, I just bought an 05 H2 SUT and while I was driving it on the highway the transmission temperature gauge pinned to max and check engine light came on. I had it towed to my place and now I’m trying to figure out if it might be a sensor or something more serious. After two hours of sitting I tried to start her up and it’s still pinned to the max temperature on the gauge. Any ideas what it could be? I also tried looking through the threads but really couldn’t find someone with the same situation.

 

Easy stuff first, check fluid level/condition & scan/post codes.

 

Thanks for the info. I already checked the fluid and looks great. I’m going to check the codes Monday morning to see what it is. I truly think it’s probably just the sensor.

 

You also checked level: running @ operating temp?
Heat is the number one cause of premature transmission failure.
Not manufacturer errors, or even defective parts. It accounts for approximately 90% of all automatic transmission failures.Excessive transmission heat is responsible for the start of many transmission problems including; ruptured seals, cracked gears, slipping transmission bands, failed bearings, inoperable solenoids, and delayed clutch engagement. You name the part, and too much heat can cause it to break.This silent killer has claimed the service life of countless transmissions, and it could be wreaking havoc on your vehicle every time you put it in gear. An overheated transmission can often go unnoticed until it’s too late and something breaks.The most common causes of overheating include low fluid, leaks, and burnt/old fluid. Other heat generating factors are if you live in a hot climate, often drive in stop and go traffic and/or tow heavy loads with your vehicle.
How Automatic Transmission Fluid Cools a Transmission.
It contains chemical additives that provide lubrication and the pressure to change gears, but its primary function is heat removal. The spinning gears, expanding springs, and whirring turbines generate friction as they move about.
This friction produces a lot of heat, which can cause stress fractures, varnishing and other forms of damage to the internal components if it isn’t dealt with quickly.
For this reason, it is formulated to absorb the heat as it flows through the moving parts. It then carries the heat out of the transmission to the radiator, where the hot fluid is forced through a special cooling chamber that uses aluminum fins to extract heat from the ATF.
As air flows through the radiator, the heat is dissipated and the cooled fluid is then piped back to the transmission for another round. If it isn’t able to remove and expel heat through the factory transmission cooler fast enough, the transmission will overheat and damage will start to set in.

 

I have it has to be to the sensor, I turned the key today and the gauge is still pinned all the way to the max. Has anyone encountered this issue? The gauge is still pinned all the way to the max, the check engine light is on and the car is running in safe mode even after more than 12 hours cooling down.

 

Replace stepper motor.

 

If you also have a check engine light and running in safe mode then most likely the sensor and not the cluster itself.