Tires are untested, the AWD module is untested. Probably easier to check the AWD module for poor connectivity, may be a burnt pin or something like that causing the whole issue. Should be behind the right hand side cowl trim panel.
I am sure the dealer updated the RDU/ATC barcode in the AWD module also, but worth a check.
NOTE:
DTC P1635 (Tire/Axle Out of Acceptable Range) — When the 4X4 control module detects an inappropriate size mini spare or road wheels/tires (greater than 7% difference in size across the front and rear axle or greater than 14% difference in size at one wheel on either the front or rear axle) installed, this DTC will be set.
Visual Inspection Chart
Mechanical
Active Torque Coupling (ATC) solenoid (part of rear axle)
Power Transfer Unit (PTU)
Rear Drive Unit (RDU)
Halfshafts and CV joints
Driveshaft and U-joints
Fluid leaks
Wheel/tire size and brand
Matching tire size and brand
Tire pressure
Electrical
Smart Junction Box (SJB) fuse(s):
11 (10A)
35 (10A)
4X4 control module
Wiring harness
Connector(s)
Circuitry
Pinpoint Test A: All-Wheel Drive (AWD) System Functional Test
Normal Operation
The All-Wheel Drive (AWD) system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is delivered to the front wheels. If wheel slip between the front and rear wheels is detected, or if the vehicle is under heavy acceleration, the AWD system increases torque to the rear wheels to prevent or control wheel slip. When the AWD system is functioning properly, there should be no perceived speed difference between the front and rear axles when launching or driving the vehicle on any uniform surface. Traction should be similar to a part time Four-Wheel Drive (4WD) system in 4H (4X4 HIGH), but have no binding in turns.
This pinpoint test is intended to diagnose the following:
AWD system concern without on-demand or continuous DTCs
PINPOINT TEST A: AWD SYSTEM FUNCTIONAL TEST
WARNING: When directed to drive the vehicle as part of this test, drive the vehicle on a hard surface in an area without traffic to prevent a crash. Failure to follow these instructions may result in personal injury.
NOTE: Carry out a thorough inspection and verification as outlined before carrying out this pinpoint test. Refer to Inspection and Verification in this section.
Test Step Result / Action to Take
A1 CHECK FOR ATC SOLENOID (PART OF REAR AXLE) LOCK
Drive the vehicle on a dry, hard surface in turns while applying the accelerator pedal.
Is driveline wind-up present in turns?
Yes
With the ignition ON, allow the ATC solenoid to cool down for at least 10 minutes and repeat the test. CHECK for wind-up again. If no wind-up is found, GO to A3 . If still present, GO to Pinpoint Test E .
No
GO to A2 .
A2 CHECK FOR VALID ACCELERATOR PEDAL POSITION MONITORING THE ACCELERATOR PEDAL POSITION (AP) PID
Enter the following diagnostic mode on the scan tool: DataLogger — 4X4 Control Module.
Monitor the AP PID while pressing the accelerator pedal.
Does the accelerator pedal position match the AP PID percent value?
Yes
GO to A3 .
No
REFER to the Powertrain Control/Emissions Diagnosis (PC/ED) manual to diagnose the accelerator pedal position sensor concern.
A3 CHECK 4X4 CONTROL MODULE WHEEL SPEED SENSOR PIDs
Enter the following diagnostic mode on the scan tool: DataLogger — 4X4 Control Module.
While driving the vehicle at 48 km/h (30 mph), monitor the following wheel speed sensor PIDs:
Left Front Wheel Speed Sensor (LF_WSPD)
Left Rear Wheel Speed Sensor (LR_WSPD)
Right Front Wheel Speed Sensor (RF_WSPD)
Right Rear Wheel Speed Sensor (RR_WSPD)
Are all 4 wheel speeds within 2 km/h (1.2 mph) of each other?
Yes
GO to A4 .
No
GO to Pinpoint Test F .
A4 CHECK VEHICLE ACCELERATION IN A STRAIGHT LINE
Carry out 3 accelerations from 0-48 km/h (0-30 mph) in a straight line (1 each with low, medium and full accelerator pedal application).
Does the vehicle pulsate or shudder while accelerating?
Yes
GO to Pinpoint Test E .
No
GO to A5 .
A5 CHECK VEHICLE TURNING ABILITY
Drive the vehicle in a fully locked turn, on dry pavement, at 8 km/h (5 mph).
Does the vehicle bind in the turn or resist turning?
Yes
GO to Pinpoint Test E .
No
GO to A6 .
A6 CHECK FOR TORQUE AT REAR WHEELS USING OUTPUT CONTROL COMMAND #1 (CLCH_SOL) ACTIVE COMMAND
Enter the following diagnostic mode on the scan tool: DataLogger — 4X4 Control Module.
Using the scan tool, command CLCH_SOL to energize the ATC solenoid to a constant 100% applied.
Drive the vehicle in a fully locked turn, on dry pavement, at 8 km/h (5 mph).
Does the vehicle bind in the turn or resist turning?
Yes
END the active command. The concern cannot be duplicated at this time. RETURN the vehicle to the customer.
No
END the active command. CHECK that the driveshaft rotates when the transaxle is in gear. If yes, GO to Pinpoint Test D . If no, CHECK the Power Transfer Unit (PTU). REFER to Section 308-07B .