problems with shifting, check engine light, ERG code.

[Stevo]

I had all of these problems show up. I made a short trip through winding mountain roads using the trailer mode in my 2020 Ranger Lariat.
I pulled into the campsite and as I was backing the trailer in I noticed the check engine light was on. I was very surprised at this because I was so excited about the trip up to the campsite. The truck behaved beautifully in trailer mode, it made all the right shifts up and down and I was very impressed with everything. Usually I put the vehicle in sport mode and make most of the shifts manually, but this time I decided to the let the computer make the decisions and I was amazed at how wonderfully well that went.
So when it was time to go home after a few days, it was quite a different story. The engine light was still on and I had to manually shift my way home.
I took the truck into the dealership and was fortunate enough to have the head mechanic come out and do a scan to see why the engine light was on . He said it was an ERG ? code and it was the sensor was probably wet or something and it wasn't reading properly. Ok so the estimate to replace the sensor was over $300 for the sensor and one hours labour which brought the cost to around $500. (with taxes)
I decided to ponder this for awhile, In the meantime the truck would run smooth one day and the light would go out and then I would park the truck to go into a store and when I came out, the truck would not behave properly at all, It would jerk and stutter and it seemed the transmission was trying to shift all the time. I shut out most of the gears and it still seemed to be trying to shift all the time. I didn't know if I would make it out of the parking lot.

I went back to the dealership and took the Head mechanic for a spin and of course everything worked well. I was left frantically trying to find an older truck that didn't have all this technology. Screw the 10 speed give a three speed auto with a torque converter.

Any way, Yesterday I was lying in bed at 4:00 AM and started thinking about all of this problem. As I lay there I found myself recapping all of the things that were going on with the truck. I also remembered there had been some strange messages on the onboard computer screen about things being shut down to save the battery. I thought about this and began to wonder if the battery might have something to do with all of these problems I was having. It made sense actually, the truck was approaching 5 years old, blah blah blah. Thinking about the sensor issue the low voltage would probably be low enough to send a lowered voltage through the sensor giving and erroneous message on the fuel mixture which would make the transmission react and I thought I better check this out when I got out of bed.
When I got up that morning the first thing I did was take my multimeter and check the battery voltage. 12.3VDC! Not enough..

I went down to the local Lordco store and picked up a replacement battery with 800 CCA, AGM etc.

The truck is now running like the day I bought it. (fingers crossed) Go FIGURE.. Why wouldn't the service manager and the head mechanic think about that??
I'll let you know if my truck is still schizophrenic.
cheers

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[ctechbob]

You should probably go ahead and replace the DPFE sensor if it has never been done. There's a pile of posts here about it and it is a super common problem.

The DPFE is part of the EGR system and will cause all kinds of wonkyness that you will swear is a transmission acting up.

 

[airline tech]

More of a FYI, 12.3 Volts is (Normal) for Wake Up voltage with the BMS system, however with your noted message (system off to save battery-Sync) and if you have not performed any preventive maintenance on the battery (maintainer, external charging and repair) you most likely had a high IR reading and it was a good idea to replace the battery.
FYI, the DPFE is only a 5-Volt (VREF) circuit, so a low battery voltage would not have a major impact on the EGR system.
Do you know what the code was? P139C? is the most common (if it codes at all)
you had the battery disconnected so it will take a few drive cycles to present itself if it still faulty.
You may also want to perform the BMS system reset after the battery replacement.

 

[Stevo]

More of a FYI, 12.3 Volts is (Normal) for Wake Up voltage with the BMS system, however with your noted message (system off to save battery-Sync) and if you have not performed any preventive maintenance on the battery (maintainer, external charging and repair) you most likely had a high IR reading and it was a good idea to replace the battery.
FYI, the DPFE is only a 5-Volt (VREF) circuit, so a low battery voltage would not have a major impact on the EGR system.
Do you know what the code was? P139C? is the most common (if it codes at all)
you had the battery disconnected so it will take a few drive cycles to present itself if it still faulty.
You may also want to perform the BMS system reset after the battery replacement.

Thank You. I appreciate your input. I have only 30,000 miles on the truck and never expected to have to do anything to the battery or have any problems with anything at this stage of the vehicles life. But here I am, when the mechanic tested the truck with the engine light on, he said it was the DPFE sensor. It seems everything is back to normal with the new battery but it's only been 1 day.
I don't have any idea as to how to reset the BMS system except how to reset the auto power window for the drivers window. I learned about that today thanks to youtube.

I am not used to having to pay people to work on my vehicles, I can usually figure stuff out, this computerized stuff is pretty much beyond me.

I am a retired electrician and I do own a megger. Where do you conduct a megger test in order to get the IR reading. Is this a path to ground measurement between the disconnected hot lead to ground? What value would I use? my megger settings are from 50 to 1000 VDC

 

[airline tech]

Most newer battery tester are now non load testing type, and they provide tests results such as this:

Just hook directly to the battery posts, with the design of the (BMFL) it is somewhat a challenge to get a perfect connection without disconnecting the battery cables., so you just hook up for the initial test and get a baseline reading, then all future tests you have a comparison to use.
These testers are not the greatest as they are under a $100, but they do provide a good reference point for battery health.

The BMS reset can be done with a Scan Tool or there is a manual method, with the Brake Pedal and the headlights, I cannot remember the procedure but I personally do not like the manual method as you have (ZERO) confirmation other than the battery light (IPC) that is was truly reset.
With the Scan Tool or Forscan, you will have a message stating successful and you can also view the Battery Life (Time Since Installed) PID will reset to (0) Days.

All this is covered in these threads:

Maximizing Battery Life | 2019+ Ford Ranger and Raptor Forum (5th Generation) - Ranger5G.com

Charging Sys-Full Description-Trigger Voltages-Test Results | 2019+ Ford Ranger and Raptor Forum (5th Generation) - Ranger5G.com

and of course the DPFE issue is covered here and other threads
Its not hard to replace, prices vary for the part (itself), and since it coded which is rare, more than likely it is bad or has moisture in it (the most common) finding, but before you replace it, confirm what the code was - most reported is P139C, the only true way to test it - is view live data PID's for the DPFE and EGR Valve (Open Percentage) and also the MAPT sensor reading when EGR is flowing and when it is not flowing.

Bucking/Surging Epidemic | 2019+ Ford Ranger and Raptor Forum (5th Generation) - Ranger5G.com

 

[skrumpe]

I think I can say with all fairness that the mechanic and service manager were working with the information given to them. Had you mentioned the battery message, they might have wanted to check the battery first. It could also be due to how experienced they are, but I have to think the head mechanic and service writer are pretty knowledgeable about our trucks.

I often have to question customers to properly diagnose a car to sell the right part or at least help them know what to tell a shop, and sometimes something seemingly unconnected makes all the difference.

 

[Stevo]

THANKS for the reply.. This forum is pretty awesome.. Cheers

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