Bucking/Surging Epidemic

[rgsheehan]

MrBusses et al:
Hello. First post here. I heard about you folks over on an Edge forum. It looks like there are a whole bunch of us dealing with this issue. I would like to paste in what I wrote over there and see what you guys think. In particular, I am trying to figure out what the Forscan data is telling me. Would really appreciate your expertise. So:

Hello,

First time post here, but I've been reading various posts on this site for a while now. Recently purchased a 2020 Edge SEL Awd. Very good condition, very low miles (15k). Dealer gave me the old 'Previously owned by an elderly couple, rarely drove it, etc, etc'. Maybe that's actually true and the mileage is correct, or maybe somebody has figured out how to modify the modern odometers, I don't know. But the car is pretty darn cherry, has tires with period correct DOT stamps, the pedals don't look at all worn. So, who knows. The dealer did give me the Ford Certified Extended Warranty, for whatever that is worth.

Anyway, after watching for more than two weeks while the snow (Erie, PA) piled up around, and almost completely covering the vehicle, the weather finally broke and I got around to actually driving it some. And discovered it has the 'surge', and 'hesitation' issues described here and elsewhere. The term 'Bucking' seems a little extreme to me, it does not slam any shifts, up or down. The car idles perfectly, has pretty darn good acceleration when asked, and seems to cruise well. Getting 27-29 mpg on the highway. But, holy crap, mild acceleration up through gears 1,2,and 3 just make this old musclecar tuner cringe. Not really a dead miss, doesn't really feel like driveline slippage. I read someone describe it as a 'tugging'. That seems like a good description.

So, from reading posts elsewhere on this site, and one of the Ranger sites where a bunch of folks seem to have similar problems, I bought and installed a new DPFE sensor. Tried to psychologically trick myself into thinking that helped, but reality doesn't want to hear it, and I am forced to admit, it didn’t help much, if any. So, I bought an adapter, downloaded Forscan, and off we go.

My first road test log was looking at some variables I thought might be relevant to either the EGR and/or Torque Converter hypotheses. The lower two traces are Torque Converter slip, Desired and actual. Can't say I understand what I am supposed to be seeing there.

I have no idea why the DPFE and EGR signals chatter around like that. Looks really noisy to me.

Anyway, anybody see anything worth investigating further?

Thanks in advance.

-rgs

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[airline tech]

Ok, Repost since it was dumped (server issue)

I wanted to post some screenshots of normal PID parameters that I pulled from my truck, I have no issues with Buck or Surge etc.
However note that to get these PIDs you must have a scanner capable of displaying (ALL) of them- Forscan is limited on what is loaded into the software and in previous trys with the older versions, some of these are missing
This will hopefully help those that have replaced the DPFE and still experience the Buck/Surge symptoms and give a reference to normal PID parameters.

I loaded all relevant PIDs I could think of that are related to the EGR system and took screenshots at
Idle & 2000 RPM.
This was not a drive cycle, these were taken parked, the 2,000 RPM shots were taken with truck in gear (parking brake set) and foot on the brake to load up the engine.

The most important PIDs to view are the DPFE (Pressure/Voltage) @ Idle & 2,000 RPM and the amount the EGR valve is open - most importantly is the EGR valve is closed @ Idle and only open 17% @ 2,000 RPM.

Note: slight variance of values may be noted, but you do not want to see any major difference.

The issue is example of a failed DPFE would be the EGR Valve is open to a greater percentage than 17%, this is what bogs down the engine and it cannot overcome the extra flow of exhaust.
For example @ 71% vs 17%, if the DPFE is under reading the actual flow it continues to command the EGR valve to open until it matches the commanded percentage, this is how the EGR valve can be commanded open to a greater percentage than it needs to be.
So the DPFE does not see that the EGR valve is actually opened to 71%, it sees it at a lower percentage and not enough.

I included the MAPT sensor PiDs for the simple fact that the MAPT sensor sees the increased EGR flow and the MAPT sensor also is an important sensor for Fuel / Timing Control.

Plus to clarify:

The DPFE Sensor & Exhaust Pressure Sensor are 2 separate sensors

The DPFE is mounted next to the MAPT sensor (Left side of engine)
The Exhaust Pressure Sensor is mounted next to the EGR valve, (Right/Rear Top of engine)
The Exhaust Temp Sensor is mounted on the same EGR Tube assembly where the DPFE hoses route.

Normal EGR Related PIDs

Note: At Idle the DPFE Pressure = (-0) you want to see a (Negative (-) reading at idle

Idle - Screen 1

Idle - Screen 2
I realized that part of the top of the screen was cut off, so I edited the screenshot.

2,000 RPM Screen 1

In Gear and (engine under load)
Park Brake Set & Foot on Brake

2,000 RPM - Screen 2
I realized that part of the top of the screen was cut off, so I edited the screenshot.

 

[rgsheehan]

AT,
Thanks for the post. I must have a later version of Forscan than you used, because I can track all the variables in your screens. The static values you posted are useful but don't give me insight into how things are working under road conditions. If you can ever post runtime traces, I would be very interested.

Sensor readings that 'appear' incorrect can result from a variety of causes. The sensor itself, the wiring between it and the PCM, problems with the A/D conversion system within the PCM, or software (maybe some other stuff, who knows).

I have other traces with the EGR valve disconnected, and the DPFE data, while not appearing to show much change in average flow (from nominal), it does still show a fair amount of noise. I don't really get that, probably time to put a real scope on it.

I have figured out I don't need to monitor both the voltage and % values for the EGRVP, since they track identically. I'll just stick with the voltage going forward. Same seems to be true for the DPFE data.

It really looks like I have both of the problems that seem to plague these Ford Edges. It runs like crap, and it shifts like crap, usually at the same time. I have Forscan traces tracking throttle position, vehicle speed, rpm, torque convert lockup, EGR, and DPFE. They clearly show the vehicle approaching the 'bad' speed range, and then pulling the EGR open, shifting to a higher gear, and trying to engage the torque converter lockup, all at about 20-25 miles per hour. Needless to say, from the driver's seat, it tugs and bumps and just feels like a POS. Stomp on it, it will take off like a scalded dog, and pull hard and smooth all the way to redline.

Ford techs looked at it twice (under warranty). 'No codes, no problems'.
I have owned many Fords, this will almost certainly be the last one.

 

[TJC]

Great write up! I grabbed the essentials prior to the crash and added them to my notebook.

Thanks for taking the time!

 

[TJC]

AT,
Thanks for the post. I must have a later version of Forscan than you used, because I can track all the variables in your screens. The static values you posted are useful but don't give me insight into how things are working under road conditions. If you can ever post runtime traces, I would be very interested.

Sensor readings that 'appear' incorrect can result from a variety of causes. The sensor itself, the wiring between it and the PCM, problems with the A/D conversion system within the PCM, or software (maybe some other stuff, who knows).

I have other traces with the EGR valve disconnected, and the DPFE data, while not appearing to show much change in average flow (from nominal), it does still show a fair amount of noise. I don't really get that, probably time to put a real scope on it.

I have figured out I don't need to monitor both the voltage and % values for the EGRVP, since they track identically. I'll just stick with the voltage going forward. Same seems to be true for the DPFE data.

It really looks like I have both of the problems that seem to plague these Ford Edges. It runs like crap, and it shifts like crap, usually at the same time. I have Forscan traces tracking throttle position, vehicle speed, rpm, torque convert lockup, EGR, and DPFE. They clearly show the vehicle approaching the 'bad' speed range, and then pulling the EGR open, shifting to a higher gear, and trying to engage the torque converter lockup, all at about 20-25 miles per hour. Needless to say, from the driver's seat, it tugs and bumps and just feels like a POS. Stomp on it, it will take off like a scalded dog, and pull hard and smooth all the way to redline.

Ford techs looked at it twice (under warranty). 'No codes, no problems'.
I have owned many Fords, this will almost certainly be the last one.

Like others, changing the DPFE sensor cured the last of my wonky shifts and bumpy low end performance. I find it amazing how these things are all so interconnected. Old mechanical autos never had these type of issues.... and lasted much longer too.

 

[airline tech]

I threw this together - Operation Notes

Just something to factor in a as a possible issue for those with continued issues after the DPFE replacement.

The only way to confirm is Live Data view of the EGR PIDs and or remove and inspect the tube assembly

 

[airline tech]

I Posted some more detailed PID Data here related to fuel trims and DPFE

Engine PID Data- Fuel Trims and Related | 2019+ Ford Ranger and Raptor Forum (5th Generation) - Ranger5G.com

 

[colin39]

I have a 3.2 ranger 2019/2020
I've have the vehicle for about 26 months since march I've been fighting a surge/bucking or throttle cut no fault code , I call it "money pit" I have replaced
The Inlet metering valve
5x injectors
3x Maff sensors
3x turbos
1x gearbox
1x throttle pedal
Boost hoses for solid pipes
Every sensor more than once
10, could be 15 fuel filters

Now not to be beaten in toying with the idea of replacing the big bit in-between the number plates


Any ideas appreciated

By the way, I'm Colin and I have an addiction it's black and built wrong

 

[Motorpsychology]

 

[colin39]

No mate sorry, I'm in a position where I just need a little help, I have detonated a parts bomb but I'm still at a loss

 

[Motorpsychology]

I'll back off, Colin.

First of all, we don't have the 3.2L Diesel in North America where the majority of members are located, however there are some from other shores who may be able to help. My, "just a guy on the Internet" guess is a problem with the shift drum in the 10R80 automatic transmission or an emissions fault- see below. If you have the manual, then I don't know.
In any case, you have already spent more money than the truck is worth, IMO.

As it happens, mine (US-spec 2.3L Ecoboost 4/10R80 a.t.) goes into the shop this Tuesday for a similar problem. I suspect a DPFE sensor (Differential Pressure Feedback Exhaust (DPFE) sensor) that sends data to a module that controls the EGR valve. I'll post results here. Bought mine new in 2021 and have had 92,700 trouble free miles (149,186km) until now.

 

[colin39]

I'll back off, Colin.

First of all, we don't have the 3.2L Diesel in North America where the majority of members are located, however there are some from other shores who may be able to help. My, "just a guy on the Internet" guess is a problem with the shift drum in the 10R80 automatic transmission or an emissions fault- see below. If you have the manual, then I don't know.
In any case, you have already spent more money than the truck is worth, IMO.

As it happens, mine (US-spec 2.3L Ecoboost 4/10R80 a.t.) goes into the shop this Tuesday for a similar problem. I suspect a DPFE sensor (Differential Pressure Feedback Exhaust (DPFE) sensor) that sends data to a module that controls the EGR valve. I'll post results here. Bought mine new in 2021 and have had 92,700 trouble free miles (149,186km) until now.

The differential sensor on the petrol? I've read about these buddy , it creates a similar problem, that's the reason I changed my 6r80 box as when it stutters the gearbox calls for a neutral,bor worst still 1st gear, and when slowing from 60mph and it calls for first it makes ya bum pucker a bit

 

[airline tech]

The differential sensor on the petrol? I've read about these buddy , it creates a similar problem, that's the reason I changed my 6r80 box as when it stutters the gearbox calls for a neutral,bor worst still 1st gear, and when slowing from 60mph and it calls for first it makes ya bum pucker a bit

Have you had a better scan tool on it to monitor Live PIds, such as the MAP sensor.
It truly appears you have a bad MAP or a wiring problem on the 5-Volt Ref Circuit.
A Live Data Monitor while driving will show what's going on, Forscan is limited for t-Shooting this.
Something is dropping out and I believe its a wiring issue pulling down the VREF circuit.

This needs a wiring diagram for the 3.2 engine control circuit to isolate it

 

[colin39]

Have you had a better scan tool on it to monitor Live PIds, such as the MAP sensor.
It truly appears you have a bad MAP or a wiring problem on the 5-Volt Ref Circuit.
A Live Data Monitor while driving will show what's going on, Forscan is limited for t-Shooting this.
Something is dropping out and I believe its a wiring issue pulling down the VREF circuit.

This needs a wiring diagram for the 3.2 engine control circuit to isolate it

I use forscan and frds have just bought the thinkcar which is real fast it's gotta be a wiring fault as I've changed every sensor.

 

[airline tech]

The differential sensor on the petrol? I've read about these buddy , it creates a similar problem, that's the reason I changed my 6r80 box as when it stutters the gearbox calls for a neutral,bor worst still 1st gear, and when slowing from 60mph and it calls for first it makes ya bum pucker a bit

I would check the MAP Sensor and Circuit as well as the (Diesel Variant of the DPFE is the DPF) and circuit.

With it shifting to (neutral) and (downshifting to 1st) on its own

I would check this circuit for the 3.2 with the 6R80, it should be similar except you have a TCM in the system for the transmission - the US Version uses the PCM for Transmission control.

Note: This is for a 10R80 and this uses a 9 Volt (VREF) circuit

Your mentioned issues Buck/Surge - Shifting to (N) etc may tie into this specific VREF Circuit



Take a look at the (2) TR Sensor PIDs A&B, anything look abnormal?
Plus you might try checking on the selector cable adjustment, it may be slightly out of adjustment.

Should be similar to this: Note the (100%) Total above (TR Sensor)
Note: PWM = The Duty Cycle (PID)

Again - I have a hunch that your issue is here and needs to be checked.

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