Bucking/Surging Epidemic

[2021Ranger]

Reading threw this and maybe my issue but I have a 2021 with 7000 miles on it and it has a surge in 3 gear a couple times.
I had an Oldsmobile that did that and it was the egr valve it had a 3 stage valve..
What do you think? For the price I think I’m just going to order one and give it a try..

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[Shawn_Mc]

The main issue I'm running into, or better described as the torque converter isn't unlocking when coming to a stop. In the mornings, when it's cold, as I roll to a stop for the same intersection, at about 3-4 mph, it feels like I hit something. If you've ever driven a manual transmission car and didn't push in the clutch when coming to a stop soon enough, as the engine drops down below a typical idle speed, you're literally loading the engine into a non run state with force at low speed. But push that clutch in, the whole vehicle will BUMP and bump hard as you do as the drive train unloads. That's exactly what happens when the torque converter lock up clutch doesn't release. The engine is still directly connected to the rear wheels though the TC. Why on god's green earth you'd lock the clutch up in anything less than 7th (1:1 ratio) I have no idea. You're not going to increase gas mileage by locking up the torque converter in less than 1:1 ratios anyway. Its a stupid strategy. Anyway...
But, they are and the converter isn't coming unlocked, at least on my truck. The 1-2, or 1-3 shift is usually bad. Especially if you're in a parking lot going slow, it accelerates the truck WAY too much, probably because they've locked up the torque converter already. Mine goes to a Dealership that I used to Service Write for on Friday, next week. We'll see what they say.

Someone mentioned a scan tool capable to disabling the torque converter lockup. What tool is this? Can I reprogram shift points and lock up, or simply eliminate the lock up for diagnosis purposes with it? If I could throw a tune at the trans, I'd drop $4-500 bucks on it in heartbeat.

 

[Rkmiller55]

I'll pile on with everyone. The bucking was terrible. The dealership said I have to live with it. Then I found this forum. I ordered LB5Z-9J433-B, received it and after a 10 min install my bucking is gone. It's such a simple fix and in hindsight, the dealer saved me a few hundred dollars. This fix is a DIY for sure. How in the world are the dealers not aware of this issue and fix? The 10 speed transmission is in several vehicles, which also experience the issue. Glad I'm back to a normal driving truck.

 

[airline tech]

I'll pile on with everyone. The bucking was terrible. The dealership said I have to live with it. Then I found this forum. I ordered LB5Z-9J433-B, received it and after a 10 min install my bucking is gone. It's such a simple fix and in hindsight, the dealer saved me a few hundred dollars. This fix is a DIY for sure. How in the world are the dealers not aware of this issue and fix? The 10 speed transmission is in several vehicles, which also experience the issue. Glad I'm back to a normal driving truck.

Due to the fact that for most (not all) this is not generating a code, Dealer = No-Code / No-Problem.
However, if they know what they are looking for - The DPFE PID parameter, they will see that it is out of specs. The trigger parameters are set higher, and the symptoms appear before it will code.
When it gets bad enough to code, it will set P139C.
P139C - Points directly at the DPFE sensor (Hey, look at me-somethings wrong with what I am reading)

 

[dtech]

I will add to this thread that if Ford really wanted to I'm pretty confident they could figure out how to set a DTC , the key phase being "really wanted to" . And just to add when I've written suggesting to some to disco the BMS to promote battery health I've encountered responses suggesting that Ford engineers are infallible and all knowing, I beg to differ.

And a dealer telling a customer "you'll just have to live with it" - lame.

 

[Tony Robyn]

Although true, with the DPFE voltage PID, it may or may not show a problem.
But being that a Torque Convertor and Transmission Relearns are being performed by dealers, and still have the same issues, and then some owners are replacing the DPFE, and problem goes away.
I cannot see a dealer replacing a Torque Convertor, for a EGR system related code.
There are other sensors that tie into the EGR system to control the EGR valve position, but by this thread and other online sites, it appears that the DPFE sensor is a known failure part and has been for years. This is the main reason I am wanting to focus on that specific part of the system without troubleshooting the whole system (No-Code) diagnostics.

So, we need to re-shift focus away from the transmission and focus on the EGR system, with it being that owners on here are reporting a positive fix with the DPFE, I would focus on what the voltage reading is for it.

This is why, I would like to see some checks before replacing it, vs just throw a part at it.
To get a confirmed - out of spec voltage reading that is not generating a code.
I have not had time yet to hook up and provide some normal readings for comparison checking with all other members on this forum.

Being that the Ford manuals are vague with testing DPFE and gives you a wide range of specs this is why a posting of a failed sensor value (without) a fault code vs a working normally system to compare values, would be helpful to owners who are experiencing this drivability issue.
Side by Side Comparision.

Here are some system descriptions.
From Online source:
Note any ref to vacuum control to EGR is not related to the Ranger, ours is electronically controlled.

Taking a closer look at how Ford does EGR | Vehicle Service Pros

and

Ford EGR-ESM Diagnosis (underhoodservice.com)

From the service manuals - PDF's

I have been having what I thought were transmission slips and took my 2019 Lariat in. They could not replicate the issue in the small amount of time they ran their diagnosis and tested. Service tech mentioned maybe the DPFE sensor. Can this just be replaced without issue. How difficult is it?

 

[ctechbob]

I have been having what I thought were transmission slips and took my 2019 Lariat in. Service tech mentioned maybe the DPFE sensor. Can this just be replaced without issue. How difficult is it?

Depends on which one you buy. I buy the $19 ones that require being clamped back on. I use crimp clamps, but you could just as well use old style worm drive clamps.

Not a difficult job either way.

 

[Luke Nukem]

I just registered to post that I read every page in this thread, changed out the sensor, and it fixed the problems I was having. It took about 15 minutes and a pair of needle-nose channel locks. Thanks!

 

[Michel Jeanneau]

I just joined the DPFE sensor replace club...noticeable difference. I went up down and sideways and coudn't find one of those things at $19...I ended up paying $59 plus shipping for a Ford part. What's funny is that on the fordparts website, they listed for$119 and came with hoses and bracket, but, if I typed my VIN it told me that "this part does not fit your vehicle"...funny! I even took a picture. The install went kinda rough; it was cold and the tons of sharp plastic bits in that part of the motor left my hand looking like it got in a fight with a stray cat

 

[pboggini]

Add me to the DPFE sensor club too at just over 61,000 miles. I noticed a few weeks ago some slight bucking while cruising at lower speeds ~30-45 MPH or so and my web search landed me on this thread. The sensor price has climbed dramatically and so it was around $100 locally here in CA. It took me around 15-20 minutes to swap it out and it definitely seems better so far in my short test drive. Will know more tomorrow.

One other thing I think it got rid of was a slight hesitation at tip in as slight acceleration does seem smoother.

I assume this would have likely been covered in my 8 year/150K mile Premium Car warranty but the thought of trying to convince a service tech that it was this when there were not codes just made me think "screw it, I'll just do it myself".

 

[notsolinear]

Apologies if I missed this somewhere in the 42 pages, but has anyone else continued to have symptoms even after replacing the DPFE sensor? If so, what else did you check or end up fixing?

 

[pboggini]

I have not continued to have symptoms after swapping out the DPFE. It's much smoother than before.

 

[Msfitoy]

Apologies if I missed this somewhere in the 42 pages, but has anyone else continued to have symptoms even after replacing the DPFE sensor? If so, what else did you check or end up fixing?

Nope...all symptoms gone after DPFE replacement...you still having issues?

 

[Yinzcity]

Apologies if I missed this somewhere in the 42 pages, but has anyone else continued to have symptoms even after replacing the DPFE sensor? If so, what else did you check or end up fixing?

Still have the hesitation on tip in here. Replacing the sensor makes it better, but it degrades after several months. Changed the sensor about 4 times now.

Not sure what the whole issue is, seems better in the winter when the air is cold and dry and worse on damp days. I haven't figured out what the cure is, but the EGR system is definitely part of it.

 

[notsolinear]

Nope...all symptoms gone after DPFE replacement...you still having issues?

Yeah, still having the feeling of hesitation occasionally when driving with very light throttle at constant speed around town. I know the main recommendation is to replace the pressure sensor, but has anyone replaced the valve or actuator that complements the sensor? (In case it’s the same effect but different part to blame?)

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