High Idle poor shifting with hot outside temperatures

[wdchparks]

I have a 1999 silverado 2500 6.0 auto tran

When the weather temp gets hot outside my idle goes up and my tranny does not shift properly.

This is with or without the A/C on. The idle rises to about 1000-1200.

No codes are showing up

It is not a tuneup, wires, air in the tires, etc. Vehicle is maintianed.

Has anyone had this problem and found a cure. The Non dealer affordable mechanic I do use wants to blow a code first. I dont want to wait. I am thinking a sensor somewhere is going bad and does not like the heat

Thankyou to any and all who respond!

[j cAT]

Originally Posted by wdchparks

I have a 1999 silverado 2500 6.0 auto tran

When the weather temp gets hot outside my idle goes up and my tranny does not shift properly.

This is with or without the A/C on. The idle rises to about 1000-1200.

No codes are showing up

It is not a tuneup, wires, air in the tires, etc. Vehicle is maintianed.

Has anyone had this problem and found a cure. The Non dealer affordable mechanic I do use wants to blow a code first. I dont want to wait. I am thinking a sensor somewhere is going bad and does not like the heat

Thankyou to any and all who respond!

My guess is the ECT is out of cal... replace this sensor..this will throw no codes...find a auto tech that knows what he is doing ...he most likely has not much experience with your vehicle...

dtc codes do not tell all about whats going on..., surprisingly with no codes and the engine has running issues this sensor is usually the cause.. basicly the computer thinks its cold when in fact its very hot causing the engine and tranny to operate like its zero deg f...

cheap part anyway 20 .oo.......

[wdchparks]

The Cure was to replace the Throttle Position Sensor, also had a bad O2 sensor.

[j cAT]

Originally Posted by wdchparks

The Cure was to replace the Throttle Position Sensor, also had a bad O2 sensor.

with no codes and these items corrected your issues something is very wrong here !