Jerking in every gear (AWD tire tread?)

[waltong]

I have a 2013 ecoboost interceptor. I have a problem under light acceleration where the car jerks and rpms flutter through every gear.

I was told it might be the awd system getting confused. Tires are all 24/45/r20 but the tread depth is different:
5/32 front/right
8/32 front/left
7/32 back/left
7/32 back/right

Would this cause an issue?

Tire pressure light is on as well even though pressure is good.

Original wheels were 18", these are the 20" SHO rims on it now.  Does the computer require programming by the dealer if the wheel size is changed?

 

[ZSHO]

I don't think the AWD System would cause your symptoms to flutter @ every gear..

It sounds like you have a faulty TPMS or check the Speed sensors.

Here's a good article on the AWD System. .

http://www.hendonpub.com/resources/article_archive/results/details?id=5091

 

[SHOdded]

If the difference in tire height is 3% on an axle, yes, it can cause AWD problems.  3% is the tolerance limit for variance.

As it sits, the tread depth difference is not significant to AWD except if it causes traction differences.  Traction differences will cause the ABS to modulate wheel speed accordingly.

Symptoms point to PTU though, especially if they occur under light throttle at cruising speeds.  I believe there is a TSB on that somewhere.

RPM flutter is a completely different animal and could point to torque converter.

 

[ajpturbo]

That doesn't sound like a hug variation in tread depth. I would want to drain and refill the trans a few times and use a high quality fluid in the proper viscosity obviously and one that meets the oem spec. But it sounds like the torque converter a bit.

Also without working out the math I'm not sure if those overall tire diameters are the same between those 2 sizes but if there is a variation I would want to correct for that with a tune. I noticed in my IDS software that there are a couple different tire size options  that dealers can flash so if your overall diameter is different I definitely could see that affecting trans operation.

Sometimes its not clear exactly what the ECU does with all the data it gets from the sensors...There is so much today