Hi folks. Long term lurker and reader, first time poster.

I have a 1997 Ford F250HD 7.3L Powerstroke e4od Cali truck. 4wd.

I've had some hard / firm shifts with the transmission since taking on ownership a little less than a year ago. I grabbed the Torque app the other day on a whim and took a gander, noticing I have no data on my Barometric pressure sensor with Key on Engine off. Figuring this might be the culprit, I replaced the sensor. However, on replacing I still had no data on torque. When I unplug the sensor and do KOEO I eventually get a CEL for P0107. With the sensor plugged in, there is no codes after clearing and doing a KOEO test.

At this point I did some digging and found how to test the BPS connector. I followed the instructions up to the point of testing the connections on the PCM with all tests passing. I did not test connections at the PCM or take a look at the PCM yet.

Here's some questions for you fine folks.

1. Do I need to just get off my *** and test the PCM connections and/or purchase a breakout box to finish the recommended diagnostics? Could a bad PCM connection / corrosion / god knows what be my problem?

2. Did I have two bad Barometric Pressure Sensors? Do I need to go purchase yet another and return the last one? Is there a way to test the sensor itself?

3. Does the default torque app just not see data for the barometric pressure sensors and I need to input a special PID to read it and I've just been chasing ghosts the whole time?

Thanks folks.


random selection of dials I added on Torque while checking diags, including the default Baro readings

 

Well, to answer my own question... it seems like it may have been option number 3.

After poking around some more I found a custom PID for barometric pressure (below)

Entering this in gives me a Baro reading that is different than my MAP reading (by 0.1 psi), so it looks like my old (and new) sensor both work. Perhaps a bit concerning is the couple PSI higher EBP reading, but I'll tackle that later on.

I'll continue my lazily poking the truck to figure out the firm shifting phenomenon, but it seems like it is not related to my Barometric Pressure Sensor.

 

I too have noticeable shifting hardness, not bad though. Please post what you learn. Particularly interested in your diagnostic methods.
Thanks

 

Sure thing. I'll probably order an EBP sensor soon ish and see what that does.

 

I replaced my Exhaust Back-Pressure (EBP) sensor recently.
Buy a genuine Ford part from RiffRaff with the tube and fittings. A bit of a pain to get the fitting out of the exhaust manifold but doable if you take your time. Take pictures of how the tube snakes up to the sensor. Will help you a lot putting it back correctly. Helps cold weather starting. Not sure about transmission shifting. Why do you think changing the BPS will help smooth out the shifting?

 

Too late. Already bought a Napa sensor. I'll take mine out, see if I can muck with it to get a reading that's more inline with the MAP and Baro sensors when KOEO. Have the Napa sensor if it refuses to cooperate. I probably won't play with the tube at this time since I do see the sensor changing readings just fine, but biased about 2-4 psi higher than the other sensors at KOEO, which reportedly it should all be the same.

Used the search feature and folks reported in on OBS e4od power strokes that changing a bad one helped their shifts.

My thoughts were more along the lines of "replace the broken thingy, pray that the behavior I don't like gets fixed in the process".

 

[QUOTE=misut0;21575475]Too late. Already bought a Napa sensor. I'll take mine out, see if I can muck with it to get a reading that's more inline with the MAP and Baro sensors when KOEO. Have the Napa sensor if it refuses to cooperate. I probably won't play with the tube at this time since I do see the sensor changing readings just fine, but biased about 2-4 psi higher than the other sensors at KOEO, which reportedly it should all be the same.



If your tube is anything like mine, you'll need to change it. Packed hard with carbon that would not dissolve. Sensor does nothing with a clogged tube.

 

Uh oh. Well, owning a crow's foot wrench set may be in my near future in that case.