9-SPEED TRANSMISSION SHIFT DIAGNOSIS

COMMON CONCERNS: Hard Upshifts, Slow Downshifts, Shift Shock At Low Speed.

On a 2015 or 2016 TLX V6 with the 9-speed automatic, a hard shift from second to third and slow downshifts at low speed have a software history, and updates to the transmission's programming were released for them. The transmission control module is programmed to adjust its stored shift settings, called adaptation values, as the car is driven. Settings out of step with the hardware can bring harsh or late shifts.

We take your TLX on the road and reproduce the shift at the speed where you feel it. Back at the bay, a scan tool shows us the transmission's software level and its stored shift settings. From those readings we judge whether your TLX needs a software update and a relearn of those settings or a repair inside the transmission.

P-AWS ALIGNMENT AND TIRE WEAR

COMMON CONCERNS: Uneven Rear Tire Wear, Off-Center Steering Wheel, Pull After New Tires.

On a 2015-2020 front-drive TLX, the rear wheels turn inward or outward by a small amount under electronic control, a system called P-AWS. It is fitted to every 2.4L car from those years and to the front-drive V6 cars. Because that rear angle comes from the system as well as the suspension, an alignment set at the front alone leaves it unchecked, and rear toe out of setting wears the rear tires unevenly.

The generation matters for the alignment too, since P-AWS steers the rear wheels of a 2015-2020 front-drive TLX slightly, so our alignment measures all four wheels and covers the rear system as well as the front, with even tire wear as the aim. On a 2021-on TLX, which has no P-AWS, the rear angles come from the suspension alone and we set them in a conventional four-wheel alignment.

2.0L TURBO ENGINE DIAGNOSIS

COMMON CONCERNS: Hesitation On Acceleration, Flat Spot When Merging, Loss Of Power On Hills.

A 2021-on TLX runs a 2.0L turbocharged four, and the Type S carries a 3.0L turbocharged V6. Boost pressure climbs as you press the pedal, and when it comes up short or arrives late, you feel a flat spot as you merge or climb a grade.

We read live data for your TLX's turbo engine and compare the measured boost with the target boost as the car pulls under load. When the measured boost falls short of the target, we look on the boost side for a split charge-air hose or a wastegate stuck open, then run follow-up tests to find the failed part.

SH-AWD TRANSFER SPLINE REPAIR

COMMON CONCERNS: Loud Bang Under The Car, Front-Wheel Spin On Launch, Loss Of Rear Drive.

On a 2021-2023 TLX with SH-AWD, the splined joint between the transmission output and the transfer unit that feeds the rear axle can strip. With those splines stripped, the car drives on its front wheels only, and the failure can arrive with a loud bang from underneath. Full power still reaches the front wheels, so drive goes to the front wheels alone and the rear axle stops pulling.

We lift the car and check the joint between the transmission and the transfer unit to confirm whether drive is reaching the rear axle. Our repair replaces the stripped splined parts at that joint, with drive to the rear axle as its purpose.

BRAKE ROTOR AND PAD SERVICE

COMMON CONCERNS: Pedal Pulse When Stopping, Steering Wheel Shake Under Braking, Worn Pads.

A pulse in the brake pedal as you slow down is a sign of rotors worn unevenly in thickness. When a rotor runs slightly out of true as it spins, the pads brush one spot harder on every revolution and wear it thinner there. That thin spot passes under the pads with each turn of the wheel, and you feel it through the pedal.

At our San Ramon shop, we measure the pads at every wheel of your TLX and the runout on each rotor. From those numbers we choose new pads alone or pads with new rotors, and a new rotor gives the pads a surface of even thickness to press against.