GEN 2 Abrupt jerk after lifting off throttle

[Alysium]

Anyone experience a sharp and abrupt jerk after lifting off the throttle?
It feels like the truck just falls flat on its face or when you drop down several gears at high speed.

Happens after a few WOT runs and then lifting off the skinny pedal.

This has happened to my truck quite a few times already. Since then, I've had a tcm tune and drop and changed the transmission fluid/filter thinking this was transmission related.

Some basic info:
- Goosetuned, running e50
- Fresh ULV & filter, fluid level verified cold and hot.
- No other mechanical issues
- P05FF code, no other codes from forscan and scantool.

 

[Nex]

I usually wait to pull off until after I brick in her eye.

 

[Alysium]

bumping this up.

whatever is causing this is getting really annoying.

 

[FordTechOne]

You may want to look closer at P05FF, was it set when you initially scanned it or did it only set after a self test on the PCM?

 

[Alysium]

was already there when I did a scan a while back. that code doesn't have a lot of diagnostic info online.

it feels like the accelerator is functioning similiar to a momentary on/off switch. as soon as I lift off the accelerator, the truck feels like it hits a wall.

also performed a live monitor of the abs/wheel speed sensors and it was all normal, no signal dips or irregularities on the graphs.
(I bought oem front and rear spares due to a grunt noise I hear when I take a left at this street corner that has a drainage dip in it and anticipated there was an issue with the sensors.)

I do not have any sway bars so I know that that wasn't the cause of the noise.

 

[FordTechOne]

P05FF is Brake Pressure Sensor/Brake Pedal Position Sensor Correlation. It sets when the PCM detects a mismatch between the brake pressure switch (BPS) and the brake pedal position (BPP) switch.

When the brake pedal input is unreliable (DTC set), the PCM can enter a fail safe mode due to the possibility of unintended acceleration caused by the driver pressing both the brake and accelerator at the same time. I would troubleshoot that DTC before going any further.

 

[Alysium]

P05FF is Brake Pressure Sensor/Brake Pedal Position Sensor Correlation. It sets when the PCM detects a mismatch between the brake pressure switch (BPS) and the brake pedal position (BPP) switch.

When the brake pedal input is unreliable (DTC set), the PCM can enter a fail safe mode due to the possibility of unintended acceleration caused by the driver pressing both the brake and accelerator at the same time. I would troubleshoot that DTC before going any further.

I replaced the brake position sensor a couple of months ago even though the sensor tested ok, maybe the replace the brake pressure sensor as well?

you recommend any other troubleshooting avenues to check out besides the ones I jave already done?

 

[jrl2019R]

Anyone experience a sharp and abrupt jerk after lifting off the throttle?
It feels like the truck just falls flat on its face or when you drop down several gears at high speed.

Happens after a few WOT runs and then lifting off the skinny pedal.

This has happened to my truck quite a few times already. Since then, I've had a tcm tune and drop and changed the transmission fluid/filter thinking this was transmission related.

Some basic info:
- Goosetuned, running e50
- Fresh ULV & filter, fluid level verified cold and hot.
- No other mechanical issues
- P05FF code, no other codes from forscan and scantool.

Wow, just posted a new thread before I saw this. Take a look. Thanks

 

[irish222222]

Did you ever find a fix? I’m having the same issue but no codes and it’s only random.