Hello all! Hoping somebody can give me a direction on what to try next. I have a 94' F-250 7.3 turbo idi. I've owned the truck for about a year now and haven't gotten anywhere with it. Previous owner had a shop put a new transmission in and didn't seem to fix his (now mine lol) issue. Its slamming into gear, weird down shifts, acts like it doesn't know where its at. Accelerating it will go 1-3-2-3-4. Everything i've replaced on the truck regarding the transmission issue are the VSS sensor, transmission range sensor/neutral switch, tach sensor, swapped PSOM module out of another truck, sent gauge cluster out to get rebuilt. Took truck to a transmission shop, the told me everything is mechanically sound. Somedays the truck will drive 'okay', somedays perfect, and somedays not pleasant.

Current Codes

23- Throttle position sensor signal out of range, Fuel injector pump level sensor out of self test range

29- Insufficient input from VSS, Insufficient input from PSOM

65- Overdrive cancel switch not changing state; transmission fault

74- Brake On/Off switch fault; not actuated

So thats where i'm at with it. These codes are kind of leading me to believe its a computer issue, but wanted to get a second opinion on where im at with it. Thanks!

 

When you ran self test with the engine off, did you hold the accelerator pedal to the floor? If not, you'll set a code 23.

When you ran self test with the engine off, did you press the OD OFF button? If not, you'll set a code 65.

When you ran self test with the engine off, did you press the brake pedal? If not, you'll set a code 74.

Code 29 is your problem. The PCM is getting erratic vehicle speed info. That's why it is shifting erratically. It's either a bad PSM (yes, I saw that you swapped it,) a bad VSS (I saw you swapped that, too,) or a damaged wire between the VSS and the PSOM or between the PSOM and the PCM.

 

Hi Mark! When I did the testing for the codes I did both key on, engine off and key on, engine off. When engine off, I got codes 23 and 29, with engine on I got codes 65 and 74. Only during the engine on test is where I pushed accelerator, rotated steering wheel, pushed brake, and turned off overdrive. I did not put accelerator to the floor, just half way. I retest with the engine off and try all of what you said and ill update you, thanks.

 

After retesting, 65 and 74 went away. 23 and 29 still remain.

 

Then you may have a FIPL problem along with the vehicle speed problem. The FIPL (fuel injection position level) is located on the injection pump. They were a known failure item.

 

When code states "sensor out of self test range" could that be a insufficient voltage?
Thanks for the reply

 

The PCM should see full throttle voltage at the sensor during self test. It didn't see that.

 

understood, thank you