Audi A6 Typ 4G: General Information
Tire Pressure Monitoring System General Information
Refer to the Owner's Manual.
With the help of the ABS speed sensor, the Tire Pressure Monitoring System (TPMS) compares both the rolling circumference and the vibration behavior of the individual wheels. The instrument cluster display shows if there are any changes to one or more wheels. If only one wheel is affected, the location of the wheel will be indicated.
The tire pressure monitoring system is a software module in the ABS/ESP control module for detecting slow losses of pressure at a wheel. With the help of the ABS speed sensors, the TPMS compares the speed and rolling circumference of the individuals wheels. If the rolling circumference of a wheel changes, the tire pressure monitoring display indicator lamp lights up in the instrument cluster. The rolling circumference of the tire can change if:
- The tire pressure is too low.
- The tire has structural damage.
- The tire or the pressure was changed and the tire pressures were not saved.
- The vehicle is loaded on one side.
- The tires on one axle are loaded more heavily (for example when towing a trailer or driving up and down inclines).
- Snow chains are installed.
- The spare tire is installed.
- One tire per axle was changed (or if the tires were rotated from front to back or the other way around).
- The left and right wheels drive on different surfaces for an extended period of time.
Tire Pressure Monitoring Display Appearing
The tire pressure monitoring display in the instrument cluster informs the driver if the tire pressure is too low or if there is a system malfunction.
System Fault in the TPMS Display (TPMS Display +)
If the indicator lamp blinks for approximately 1 minute after switching the ignition on and then stays on continuously, there is a system malfunction. "TPMS" is also displayed in the instrument cluster.
A system malfunction is stored in the ABS/ESP control module and indicated by the yellow TPMS lamp in the instrument cluster. The TPMS lamp cannot be switched off by pressing the Multimedia System Control Head -E380- button. Proceed as follows if there is a fault stored in the Diagnostic Trouble Code (DTC) memory:
- Connect the Vehicle Diagnostic Tester and select Guided Fault Finding.
- Select the corresponding program in Guided Functions.
- Follow the prompts on the screen.
Perform Calibration: (Re-adapt Tire Pressure)
The tire pressures must be stored in the MMI each time there is a change in the tire pressure or after a tire has been changed.
- Switch the ignition on, select the "CAR" function button and select the tire pressure monitoring system using the Multimedia System Control Head -E380- knob and save the tire pressure by pressing the rotary knob.
Dynamic Steering General Information
In conventional steering system, there is a direct mechanical connection between the steering wheel and the steering gear. That means there is a constant, specific relationship between the angle of the steering wheel and the angle of the wheels. In this version, only one ratio can be used in a vehicle. Selecting the appropriate ratio is a compromise because the different and somewhat contradictory requirements must be satisfied as best as possible.
The important requirements can only be fulfilled optimally by a variable ratio. Such a ratio changes the actual steering angle of the wheels depending on the vehicle speed and steering angle. Dynamic steering generally implements two variable ratios with comfortable and sporty characteristics.
The variable ratios are implemented by an additional electromechanical steering pinion actuator that superimposes the driver's steering movement. In emergencies such an actuator malfunction, the steering functions exactly like conventional steering. The mechanical connection between the steering wheel and the front axle is not disconnected.
The advantages of dynamic steering are even more extensive. The system is also activated in conjunction with the ESP and its sensors under poor driving conditions. Through selective variation of the front wheel steering angle, the dynamic steering supports the ESP within dynamic driving limits.
The "actuator" located on the steering column is a fixed component of the column. If the "actuator" is faulty, the entire steering column must be replaced.
Correct basic setting is required for proper dynamic steering function.
Note
To make a basic setting successfully, the Steering Angle Sensor -G85- must first be calibrated using the Steering Wheel Scales -VAS6458-.
A Basic Setting Is Necessary If
- The Active Steering Control Module -J792- was replaced.
- The front axle toe was adjusted.
- The rear axle toe was adjusted.
- The vehicle suspension was changed, for example, changing from standard to sport suspension.
- The Steering Angle Sensor -G85- was calibrated.
- The steering column was replaced.
- The steering wheel is at an angle when driving straight.
Note
Before performing a basic setting on the dynamic steering, check the Diagnostic Trouble Code (DTC) memory and correct any faults. A basic setting to the dynamic steering must only be performed using alignment equipment approved by VW/Audi.
Drive Axle General Information
The wheel bearing must not be under a load while the drive axle threaded connection on the wheel side is loose.
If the bearings are loaded by the vehicle weight the wheel bearing will be damaged. This reduces the service life of the wheel bearings. Therefore observe the following:
- Procedure for loosening drive axle to wheel hub bolted connection. Refer to → Chapter "Drive Axle Threaded Connection, Loosening and Tightening".
Vehicles without a drive axle must not be moved, otherwise the wheel bearing will be damaged. If the vehicle does have to be moved, always note the following points:
- Install an outer joint in place of the drive axle.
- Tighten the outer joint to 200 Nm.
Do not let the drive axle hang down. The inner joint could be damaged if it is bent too far.
