95 F150 EC 4x4, 5.8l, E4OD, 3.55 Gears, 31 inch tires....pretty stock...

This truck is new to me, picked up really cheap and it's in really great shape. I've been pleasantly surprised as I get it cleaned up and working out little bugs.
I ran a VIN history and it seems it hasn't moved much in the last 5 years, but is high mileage (240k) All fluids look really good, oil, coolant, etc. Tranny fluid is nice and red and at the proper level. There's a small oil leak from rear of engine, but not severe. Other than that I don't know the history, but it runs fantastic, and looks to be all stock. I've put about 500 miles since I got it.

the transmission was shifting pretty smooth, as though totally stock. The only mechanical issue left is the Speedo jumps a bit over 50 mph, and gets worse the higher the speed goes. I picked up a new rear end VSS sensor and installed it, but it didn't register at all (do I need to reset the computer? Isn't it plug and play?). Threw the ABS light on, OD blinking and no Speedo at all. Took it down the street a block, and immediately back to the driveway to reinstall the old sensor. All seems back to normal and took it on about a 30 minute drive.

This morning I took it to town to get a replacement sensor and now the tranny shifts much more firm, as though its got a shift kit. Drive across town and back and both up and down shifting is pretty firm. If it had shifted this way the whole time, i would say its got a shift kit installed, but why the change? Everything else is normal...any ideas what may have changed the shifting characteristics this way? Could it be just getting some miles on it for the first time in a long time? Did the VSS issue change something?

Dan

 

Sounds like it has gone into "limp home" mode.

 

really? Shift points all normal, just suddenly extra firm...everything else normal.

Dan

 

You could run the Key On Engine Off (KOEO) tests and Stored Codes display to verify if there is a stored code for the previous bad VSS signal. I suspect there probably is. If so, clear the codes then drive the truck for a few minutes to see if everything settles down.

 

Well I'm embarrassed to say, since I doubted this feedback, that you may be right🙄.

When I got my new VSS sensor, the parts guy said I had to reset the computer for it to work. Didn't sound right to me, but it was worth s shot. I disconnected the battery, installed the new sensor. Reconnected the battery (after waiting a bit of time). The second sensor still doesn't work, so I put the old sensor back in and went for a drive. All is back to normal. So is that what limp mode feels like in these trucks? And any idea why two new VSS won't work?

Dan

 

Only code 335 (EGR Sensor) is showing, but no CEL. I have already replaced the EGR Sensor.

Dan

 

Code 335 EVP sensor voltage out of Self-Test range. Many aftermarket EVP sensors have too long of a shaft. Verify the EVP signal output Key on Engine Off (KOEO). If the signal is too high, many have filed down the EVP shaft to bring it back in range.

So two VSS sensors have no output? Are these aftermarket? After each was installed and found to be defective did you clear the codes? Code 452 Computer detected an error in the VSS or PSOM signal during the last 80 warm-up cycles. is a Stored Code only and rarely triggers a Check Engine Light (CEL).

 

That's because it isn't right. Resetting the computer does NOTHING that will help a new VSS work. Something is wrong with the new one, it's defective, or it is the wrong one for the application.

 

Here is an older thread with the same speedometer issue. Unfortunately the OP never said if it fixed the problem so is it safe to assume it did?

https://www.ford-trucks.com/forums/1...ing-funny.html

 

Yes two! They are after market from Oreillys. I am now reading how aftermarket VSS units are crap so I ordered a Motorcraft, and hopefully it works. No code other than the 335 EGR sensor. I replaced the EGR Sensor a week or two ago when it was throwing code 332 along with it, and the CEL light was on. Changing the sensor made the CEL light go out, and I didn't clear or check codes again till now. Will the code eventually clear, or since its still there do I still have an issue?

I just want my Speedo fixed cause I love cruise control, which won't operate properly, and I hate it when there's something wrong! That's my OCD thing😁...

 

Did you run both of the tests? i.e. Key On Engine Off (KOEO) tests and the Stored Code display? If there were no stored codes you would have gotten Code 111 System Pass.

 

yes, as I mentioned, I still get 335 as a stored code, though I replaced the EGR Sensor a week or so ago. Stored codes are 335, then 111...

I've never done the engine on test.

Dan

 

Code 335 is a Key On Engine Off (KOEO) code. It's not a Stored Code. Since there are no Stored Codes you got System Pass Code 111. That's good which means there is nothing in memory causing transmission shifting issue.

 

...good to know, but if that's the case then I still have an issue with my EGR sensor? Since I replaced it, which made the code 332 and the CEL go away, what would cause this?

Dan

 

Post #7: https://www.ford-trucks.com/forums/1...l#post19205367