First concern on 2021 lariat

[Davidjc]

UPDATE. . . Went for appointment, service writer told me since check engine light was off now they'd note that I brought it in, and to come back if it does it again. Said it was fairly common and described same symptoms and causes as many if you did here. I do have extended warranty so feel OK doing that. Thanks for the feedback.

Well, Friday while driving the truck around town I noticed it started to act a little off at low speeds. Holding steady at around 25mph and I could feel a little vibration in the engine, almost a sputter. A little while later I saw the check engine light come on. My 21 lariat has 31,200 miles and 36 month warranty ends next month, Dec 2024.
Next, I get a ding on my phone and had a message from the app to have it checked. So I made appt to take it in Monday morning. And of course, the check engine light went off after a few more starts and drives.
I'm still taking it in but doubt they'll see anything since it cleared. I read online that the egr can cause this pretty often. Is that something easy to change? Who's done it?

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[Grumpaw]

At that low a speed engine is probably just "lugging" and trans is most likely trying to find the right gear.
Maybe try engaging the tow/haul, if your not using it. It will change the shifts and may just keep it in a lower gear at that slow speed, instead of the trans "hunting". At a constant 25mph in regular "drive" mode, engine is probably turning over at a very low rpm, while trans is trying to find the right gear. That it is sputtering/vibrating wouldn't surprise me.
Is the 25 mph something you do only occasionally, or is it regular and the Ranger just started with the sput/vibration ?
Personally, I use the tow/haul for 100% of my driving.

 

[Davidjc]

At that low a speed engine is probably just "lugging" and trans is most likely trying to find the right gear.
Maybe try engaging the tow/haul, if your not using it. It will change the shifts and may just keep it in a lower gear at that slow speed, instead of the trans "hunting". At a constant 25mph in regular "drive" mode, engine is probably turning over at a very low rpm, while trans is trying to find the right gear. That it is sputtering/vibrating wouldn't surprise me.
Is the 25 mph something you do only occasionally, or is it regular and the Ranger just started with the sput/vibration ?
Personally, I use the tow/haul for 100% of my driving.

Driving in my town is typically slower. So mos of my driving is slower. However, the light went out after driving faster for a while. Everything seems normal now but . . .
I've only used tow hall when towing but I will see if if makes a difference next time. Thanks for that. I guess the transmission hunting can cause the light to come on? Driving the same way since I got it but first time this happened.

 

[Brett Fields]

I like tow haul also, but I've never had a light come on due to lugging. The dealer will know what caused the light.
Update the thread and let us know when you find out.

B.

 

[Davidjc]

I like tow haul also, but I've never had a light come on due to lugging. The dealer will know what caused the light.
Update the thread and let us know when you find out.

B.

Will do.

 

[RangerBill]

The code that caused the light is probably still in memory and can be read with a code reader. Could be the DPFE EGR pressure sensor as that causes engine bucking at low speeds and light throttle.

 

[Davidjc]

The code that caused the light is probably still in memory and can be read with a code reader. Could be the DPFE EGR pressure sensor as that causes engine bucking at low speeds and light throttle.

That description is what I experienced.

 

[AzScorpion]

Well, Friday while driving the truck around town I noticed it started to act a little off at low speeds. Holding steady at around 25mph and I could feel a little vibration in the engine, almost a sputter. A little while later I saw the check engine light come on. My 21 lariat has 31,200 miles and 36 month warranty ends next month, Dec 2024.
Next, I get a ding on my phone and had a message from the app to have it checked. So I made appt to take it in Monday morning. And of course, the check engine light went off after a few more starts and drives.
I'm still taking it in but doubt they'll see anything since it cleared. I read online that the egr can cause this pretty often. Is that something easy to change? Who's done it?

If you haven't already seen this there's a lengthy thread on it below. You might want to save a couple posts (and bring it with you to the dealer) outlining what others here experienced and how they fixed it. Some know right away what it is and some dealers spend days/weeks guessing what it is so this might help speed things up. Good luck!

https://www.ranger5g.com/forum/threads/bucking-surging-epidemic.14581/

 

[Davidjc]

If you haven't already seen this there's a lengthy thread on it below. You might want to save a couple posts (and bring it with you to the dealer) outlining what others here experienced and how they fixed it. Some know right away what it is and some dealers spend days/weeks guessing what it is so this might help speed things up. Good luck!

https://www.ranger5g.com/forum/threads/bucking-surging-epidemic.14581/

Thank you.

 

[airline tech]

For a No-Code DPFE Sensor issue:
Live Data - Drive Cycle and look at 2 important PIDS:

The DPFE Sensor (PSI) and the EGR Valve open (Percentage)
Some scan tools will display the DPFE Sensor in KPA or Volts

What appears to be happening is the DPFE (Under Reports) EGR Flow, so the PCM commands the EGR valve open (farther) than it needs to be.

The engine cannot handle the over command of the flow, and it stumbles.

DPFE (-) reading = No EGR Flow - DPFE (+) Reading = EGR Flow
So, the (-) reading being reported is causing the PCM to drive the EGR valve open in an attempt to obtain a (+) flow reading form the DPFE sensor.

So, if you monitor both of those PID's in a drive cycle you will clearly note the DPFE hanging in the (-) side while the EGR valve is opening to a percentage higher than normal (Normal = about 15%)
While cursing at about 55 MPH.

This is more noticeable at low speeds; the stumble is more noticeable due to the low RPM range, EGR Valve is opening at a greater percentage than it should.
EGR Valve should break open at about 1200 RPM and be a low percentage which if I recall was around 7%.

Basically, the EGR Valve will normally cycle open & closed when you drive, but if the DPFE sensor is not reading EGR flow, it will hold the EGR Valve open and also command it open farther than it needs to be. This is the Stumble / Buck / Surge.

 

[Bobby-C]

At that low a speed engine is probably just "lugging" and trans is most likely trying to find the right gear.
Maybe try engaging the tow/haul, if your not using it. It will change the shifts and may just keep it in a lower gear at that slow speed, instead of the trans "hunting". At a constant 25mph in regular "drive" mode, engine is probably turning over at a very low rpm, while trans is trying to find the right gear. That it is sputtering/vibrating wouldn't surprise me.
Is the 25 mph something you do only occasionally, or is it regular and the Ranger just started with the sput/vibration ?
Personally, I use the tow/haul for 100% of my driving.

Does tow/haul mode decrease fuel mileage. Just curious.

 

[Grumpaw]

Does tow/haul mode decrease fuel mileage. Just curious.

Can't answer as I do not keep track of my mpg...just not that important to me.
Someone else will probably chime in.....

 

[Grandaccess]

Does tow/haul mode decrease fuel mileage. Just curious.

I used tow/haul, now I just use (S) Sport mode, it feels a lot more responsive and I have not noticed any difference in MPG, I do notice between gas stations, over a tank or two I have gotten 21+mpg and over the last 7000 miles I have averaged 17.5mpg and thats a combo of city/hwy/towing

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