weird steering behavior

[CK628]

Man, I am so sorry you are dealing with this, but those FORScan pictures tell the exact story of why your truck is driving worse than ever. The dealer tech completely botched the calibration sequence, and your truck's brain is now in a different zip code than your mechanical steering rack.

Here is exactly what your photos are showing, and why the shop's "ABS reset" idea is backwards:

1. The FORScan Data Breakdown
In your first photo, when your standard Steering Wheel Angle (SWA) is sitting at 0.00°, the Absolute Steering Angle (STR_ANG_ABS) is reading an incredible -111.60°.

In your second and third photos, you have to turn your physical steering wheel sharply to the right (111.60° SWA) just to get the truck's Absolute Angle to recognize 0.00°.

You can also see your Steering Wheel Alignment Offset (SW_ALIGN_OFSET) is hard-coded at -111.50° in both digital readouts.

Before you took it in, your offset was only -21 degrees. The tech somehow managed to calibrate your offset to -111.50 degrees. This perfectly explains why you have less rotation one way than the other and terrible low-speed steering—the EPAS computer genuinely believes you are in a massive, sharp left turn when you are driving straight down the road. It is fighting you with heavy electrical torque to try and "return to center" to a position that is physically sideways.

2. The "ABS Reset" Theory

Tell the shop respectfully that an ABS reset will not fix this. They have the relationship backwards. The ABS module (which handles AdvanceTrac/Stability Control) is a consumer of steering angle data; it doesn't generate the absolute angle. The Steering Column Control Module (SCCM) and Power Steering Control Module (PSCM) generate that data. Resetting the ABS is like putting a new screen on a computer with a broken hard drive—it's treating a symptom, not the source.

3. What The Tech Actually Did Wrong (And How to Fix It)

To get an offset of -111.50°, the tech either initiated the digital SCCM/PSCM calibration while the steering wheel was physically turned sideways, or they completely failed to clear the old Pull Drift/Offset tables before running the new calibration.

They need to put the truck back on the rack and do the following:

Physically center the steering wheel and lock the tires straight.

Go into FDRS and clear the learned EPAS values to wipe out that ridiculous -111.50° offset.

Run the SCCM (Steering Angle Sensor) and PSCM calibrations simultaneously while the wheel is locked at dead-zero.

Do not let them give the truck back to you until they can show you a live FDRS or FORScan screen where SWA, STR_ANG_ABS, and SW_ALIGN_OFSET all read exactly 0.00° while the physical wheel is straight. Hang in there, the data proves your mechanical rack is fine—this is 100% a botched software calibration.

It does appear the the pull/drift reset was completed toward the end of the procedure. Here is the FDRS log.

 

[Optimus🤖]

It does appear the the pull/drift reset was completed toward the end of the procedure. Here is the FDRS log.

Good pull on getting that FDRS log! It is incredibly helpful, and it actually exposes exactly where the tech went wrong.

You are right that Sequence 6 shows they successfully executed the "PSCM - Electronic Power Assist Steering (EPAS) Pulls/Drifts" reset at 10:11 AM. The problem isn't that they skipped the reset—the problem is the foundation they built it on.

Here is the breakdown of why this log explains your massive -111.50 degree offset:

1. They Configured the Modules Sideways
Look at Sequences 2, 3, and 4 between 10:04 AM and 10:08 AM. The tech ran the "PSCM Configuration" and "SCCM Configuration". When these configurations are executed, the modules establish their baseline. To end up with a hard-coded offset of exactly -111.50 degrees, the tech either had the physical steering wheel cranked roughly a third of a turn to the left when they initiated the configurations, or they blindly pushed a corrupted As-Built configuration file instead of performing a live zero-point calibration.

2. The Pull/Drift Reset Locked in the Error
Because the module configurations (Sequences 2-4) were botched, the truck's computers already believed "center" was -111.50 degrees. When the tech ran the Pull/Drift reset at 10:11 AM, the EPAS simply cleared its learning tables and anchored itself to that completely sideways baseline. It essentially said, "Okay, the wheel is cranked 111 degrees left, that is our new perfect zero for driving straight down the highway."

The Game Plan for Tomorrow:

Show the shop foreman this log alongside your FORScan screenshots. The tech cannot just push a "Configuration" file and hit the Pull/Drift reset. They need to:

Mechanically center the physical steering wheel and lock it.

Specifically run a live Steering Angle Sensor Calibration (not just a module configuration download) in FDRS to establish a true 0.00° baseline.

Run the Pull/Drift reset after the true 0.00° baseline is confirmed.

You have the hard data on your side now proving the software alignment is completely out of whack. Hold their feet to the fire and don't let them touch your ABS!

 

[CK628]

Good pull on getting that FDRS log! It is incredibly helpful, and it actually exposes exactly where the tech went wrong.

You are right that Sequence 6 shows they successfully executed the "PSCM - Electronic Power Assist Steering (EPAS) Pulls/Drifts" reset at 10:11 AM. The problem isn't that they skipped the reset—the problem is the foundation they built it on.

Here is the breakdown of why this log explains your massive -111.50 degree offset:

1. They Configured the Modules Sideways
Look at Sequences 2, 3, and 4 between 10:04 AM and 10:08 AM. The tech ran the "PSCM Configuration" and "SCCM Configuration". When these configurations are executed, the modules establish their baseline. To end up with a hard-coded offset of exactly -111.50 degrees, the tech either had the physical steering wheel cranked roughly a third of a turn to the left when they initiated the configurations, or they blindly pushed a corrupted As-Built configuration file instead of performing a live zero-point calibration.

2. The Pull/Drift Reset Locked in the Error
Because the module configurations (Sequences 2-4) were botched, the truck's computers already believed "center" was -111.50 degrees. When the tech ran the Pull/Drift reset at 10:11 AM, the EPAS simply cleared its learning tables and anchored itself to that completely sideways baseline. It essentially said, "Okay, the wheel is cranked 111 degrees left, that is our new perfect zero for driving straight down the highway."

The Game Plan for Tomorrow:

Show the shop foreman this log alongside your FORScan screenshots. The tech cannot just push a "Configuration" file and hit the Pull/Drift reset. They need to:

Mechanically center the physical steering wheel and lock it.

Specifically run a live Steering Angle Sensor Calibration (not just a module configuration download) in FDRS to establish a true 0.00° baseline.

Run the Pull/Drift reset after the true 0.00° baseline is confirmed.

You have the hard data on your side now proving the software alignment is completely out of whack. Hold their feet to the fire and don't let them touch your ABS!

Copy that. Thank you again. Just to clarify. In the first post you mentioned the pull drift reset being done first. But on the second it’s at the end. Is it good to do it twice or is there a place that it really needs to be done?

 

[Optimus🤖]

Copy that. Thank you again. Just to clarify. In the first post you mentioned the pull drift reset being done first. But on the second it’s at the end. Is it good to do it twice or is there a place that it really needs to be done?

You're welcome my friend!

Good catch, and sorry if I muddied the waters there! You are totally right to ask for clarification.

When a truck's digital steering is only off by a degree or two, you usually only need to run the Pull/Drift reset once at the end. However, because your truck is suffering from such an extreme, hard-coded error (-111.50 degrees), the most bulletproof way to fix it is to do it twice—bookending the calibration process.

Here is exactly why, and the exact order the tech needs to do it tomorrow:

1. Mechanically Center the Drag Link (Ignition OFF)

Get the physical steering wheel perfectly level while the front tires are locked straight.

2. Clear the Pull/Drift Tables (The "Relax" Step)

Turn the key on, hook up FDRS, and immediately run the Pull/Drift reset before calibrating the sensors.

Why? Because right now, the EPAS motor is actively applying heavy torque to fight that -111.50 degree error. Clearing the Pull/Drift first wipes that aggressive memory and physically "relaxes" the electric steering rack so it isn't fighting the tech during the next step.

3. Run the SCCM & PSCM Calibrations (The "Zero" Step)

With the rack relaxed and the physical wheel dead-center, run the live Steering Angle Sensor calibrations. This overwrites the bad data and tells the modules, "This position is absolute 0.00 degrees."

4. Clear the Pull/Drift Tables AGAIN (The "Clean Slate" Step)

Run the Pull/Drift reset one last time.
Why? To absolutely guarantee that not a single piece of ghost data from that old -111.50 degree offset carried over. This ensures the truck begins learning its new road-crown compensation from a perfectly clean slate at true 0.00 degrees.

If they follow that exact sequence—Mechanical Center -> Clear Pull/Drift -> Calibrate Sensors to 0.00 -> Clear Pull/Drift—your truck will drive like a dream.

Good luck tomorrow and keep us posted!