I got a 1993 F-250 7.3 Diesel non-Turbo, automatic. Between 47 and 53 MPH the transmission constantly shifts from drive to over drive, back and forth. Little light was flashing so I pulled a couple codes and one was TPS out of range, I didn't assume it was bad but figured after 236,000 miles, heck why not replace it anyway. I put it on and still does the same thing, oh well haha. So my question is since it is "out of range," how do I need to go about adjusting it to maybe fix this problem, or is something else causing this eratic shifting??

 

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To adjust, you have to just barely loosen the screws until you get just under 1.0V at one extreme, and about 4.5V at the other extreme across the signal/ground terminals (a manual should show you which is which), with a smooth transition between the two.

I'd also check your shift linkage and your MLPS (manual lever position sensor AKA neutral safety switch). Oh, and check your fluid, too.

Jason

 

A TPS sensor is a potentiometer. When these wear out...or cause problems...they sometimes like to create dead spots or spikes in the voltage output of the sensor.

As you open the throttle, that voltage increases. It should increase smoothly and gradually up to about 4.5V at WOT. If you see any dead spots or spikes in the voltages...it's no good.

You can always verify a sensor's function before purchasing a new one blindly. I use paper clips in the 60 pin computer connector to measure the voltages at the computer.