spddm0n

Does anybody know what might cause the transmission to be in overdrive all the time? I have searched through a few of the threads that suggest coolant temperature is important when the transmission WON'T go into overdrive, but I have the opposite experience. It appears that my transmission is skipping 3rd gear (DRIVE). At 50-55 MPH, the engine feels under-powered and when I depress the gas pedal to kick it into the next lower gear, I'm pretty sure it skips 3rd gear and goes into 2nd, with super high engine RPM (no tach in my DLX model, so I'm not sure what the RPM is).

I have some cooling issues that I'm working on (water pump leaks a little bit; temperature gets a little warm when sitting at a stop in traffic; cold engine operation is really bad - hardly wants to go at all until it warms up a bit; difficulty with climate control - takes a long time to warm up and poor defrost operation). A lot of this leans toward a thermostat and water pump replacement, which is already in the works, but I'm curious if this might solve the transmission overdrive operation issue. I also read that the coolant temp sensor could be a problem too.

There are no codes stored in the EFI computer. Is it typical that a sensor could fail, and NOT throw a code? Could a sensor just be operating incorrectly, but still functional such that the EFI computer doesn't determine a "failed" sensor?

I've also ready that the TPS could be operating incorrectly. I can check that. I don't know how to check the transmission computer yet. Could there be something to learn from that? Also, what about a transmission temperature sensor? I read there may be one or two of those in the system somewhere? Would it be logical to check those for this condition?

Thanks!