Engine/Transmission (1994 - 1998) Throttle Position Sensor Replacement

[Howard Durand]

After reading Ridesamule's innovation for replacing the TPS with a potentiometer, I decided to try it myself.

I previously used a potentiometer in the ground wire to the TPS and that had a certain amount of success but the action of the transmission was still unpredictable.

What I have done now is the same as he did except I just unplugged the TPS but left it mounted and available.

With the potentiometer in the circuit I find that I can adjust the shift into overdrive anywhere between 30 mph and 50 mph.

I have fixed resistors on both ends of the pot, 500 ohms on the ground side and 1500 ohms on the PCM side. The pot is 1000 ohms. If I find that I want it to shift at an even higher speed I can change the values of the fixed resistors until I get the desired results.

I have only taken it on a short drive since getting it in but am finding that it will shift at the same mph consistently for the setting I am using. I will be taking it on a longer run next week so will know for sure.

 

[Howard Durand]

Took the truck to Wenatchee yesterday. About 125 miles round trip. With the potentiometer set at 2. 3 volts the transmission shifted into OD at 45 mph consistently.

 

[td96ram]

Howard where is the best place to get a 1000 ohm pot my local radio store couldnt help me and Radio Shack has a couple choices but no 1000 ohm

 

[Ridesamule]

On the RE transmission I don't think that the size plays that big of a difference. AS Howard stated with his application of resistors on each end of the pot. A change in the signal resistor should change the OD shift/lockup speed. I tried a few and it did make a slight difference.



Howard has obviously studied this to a depth I never will, so I will leave this as just an opinion.