Engine/Transmission (1994 - 1998) Overdrive shift is way to soon

[Dodger440]

The truck is a 96 with 4. 10 gears. At light throttle it shifts into overdrive at 24-25 mph. Lockup is ok and happens at 45 mph. I tried adjusting the TPS from . 8 volts all the way up to 1. 3 volts, but it didn't seem to make any difference. Any ideas on how to increase the speed that the OD shift takes place? Thanks guys!

 

[Missouri Mule]

From 96 FSM.

This seem to be your symptoms.

"3-4 up shift occurs immediately after 2-3 upshift.

1. Overdrive solenoid connectro or wiring short.

2. TPS malfunction.

3. PCM malunction.

4. Overdrive solenoid malfunction.

5. Valve Body malfunction.

 

[Dodger440]

From 96 FSM.

This seem to be your symptoms.

"3-4 up shift occurs immediately after 2-3 upshift.

1. Overdrive solenoid connectro or wiring short.

2. TPS malfunction.

3. PCM malunction.

4. Overdrive solenoid malfunction.

5. Valve Body malfunction.

Thanks a lot for the reply! It doesn't shift immediately after the 2-3 shift, and if you are harder on the throttle it does wind up 3rd gear a little more before it makes the shift into overdrive. Also, the shift for lockup happens at the correct MPH. I would think that would rule out the TPS???