ADT Chassis, Suspension & Brake Systems 3

Question 1

Audi uses a 'steering angle sensor' (G85) for ESP operation. After replacing a steering rack, which calibration is required?

Accepted Answer

Steering angle sensor zero-point calibration via VCDS/ODIS with front wheels centered

Answer

G85 must be re-zeroed with the steering wheel and wheels centered after any rack or steering component replacement so ESP has an accurate reference.

Question 2

A technician inspects Audi B8 A5 front lower control arm bushings. The front bushing shows radial cracking but the rear hydraulic bushing feels firm. What is the correct service decision?

Accepted Answer

Replace both lower control arms as an axle set because handling geometry changes if only one side is renewed

Answer

Audi recommends replacing control arms in axle pairs to maintain symmetric handling characteristics and avoid alignment variance side-to-side.

Question 3

During a brake job on an Audi with electric parking brake (EPB), in which sequence must caliper piston retraction be performed?

Accepted Answer

Activate EPB service mode in VCDS/ODIS first, retract piston, install new pads, then reactivate EPB

Answer

EPB-equipped Audi calipers require the electronic service mode to retract the lead-screw-driven piston safely without damaging the motor or seals.

Question 4

A technician finds a DTC for 'Wheel Speed Sensor Signal Implausible — Rear Left' on an Audi with quattro. All wheel speed sensors test good individually. What is the NEXT diagnostic step?

Accepted Answer

Compare all four wheel speed signals simultaneously during a road test to detect ratio errors from incorrect tire sizes or ABS ring damage

Answer

An 'implausible' signal fault often means the sensor is working but its output disagrees with the other three — caused by ABS ring damage, tire size mismatch, or excessive bearing play.

Question 5

On an Audi with electromechanical power steering (EPS), the steering torque sensor (G269) returns a fault. What symptom would the driver most likely report?

Accepted Answer

Steering assist varies erratically or is absent, accompanied by a steering warning light

Answer

G269 provides torque input to the EPS motor controller; a fault causes the system to reduce or disable assist and illuminate a warning.

(ADT) Audi Diagnostic Technician Practice Test

(ADT) Audi Diagnostic Technician Practice Test

ADT Chassis, Suspension & Brake Systems 3