all of a sudden the turbo sounded like it was running 50 psi and ready to fly out of the engine compartment although the boost guage only said 8-10 psi and the transmission wouldn't shift out of third and shifted very hard up to third. i pulled over and shut it off only to not be able to restart (nothing on key turn) until about the fifth attempt. as i limped home the last few miles i took notice that the trans temp guage read cold/zero but all of a sudden the guage popped up to normal op temp, the wrench indicator went away and was driving normal again. it did this twice in the 10 mile drive home. my h&s tuner told me the trouble codes were P0710 "trans fluid temp sensor A circuit" and P0713 "trans fluid temp sensor A circuit high". fluid levels where good and looked clean. assuming this is a bad sensor, do you think i'm safe to drive to the dealer 30 miles away? on a side note, when my wife said "aren't you ready to buy a chevy?"...i said no but i might be ready for blonde if you don't watch it

 

Sounds to me like your truck went into failsafe mode in order to protect the transmission. You most likely have a bad temperature sensor or a problem with the wiring between the sensor and the PCM. The fact that it came and went like that suggest that it's wiring related.

With that being the only trouble code present you should be safe driving it to the dealer, just remember that if by some fluke your transmission cooling fails you could overheat with no warning. Highly unlikely though, and I'd drive it with no worries.

 

how could the cooling system fail if the pump pushes it through the coolers? As long as the truck is running the trans is pumping fluid through the coolers no?

 

It's not uncommon to have a transmission cooling failure when the cooler becomes internally obstructed which blocks flow. That's the whole reason why the 4R100 is equipped with a bypass, otherwise the transmission would grenade quickly due to lack of lubrication without flow through the cooler.

Again, it's highly unlikely, but possible.

 

I'm going to chance it and drive it slowly on the back roads. now let's just hope the dealer actually has one of these sensors in stock...

 

Save yourself some time and money and replace the internal harness, it's covered in fluid and mainly the cause of the dreaded wrench!

 

typically the dealer will suggest things like that but they just changed the sensor and did a fluid/filter service...driving fine now.

 

I agree with the above...hope you left the codes in there for them to see.

Either way I would replace the sensor.

Also did you verify temps with the H & S?

 

I initially cleared the codes but when the problem repeated, I left them and called the dealer. My tuner was showing the trans temp fluctuations exactly the same way the dash was...went from no data to normal instantly. I also has the #2 glow plug replaced since it was throwing a code...$550