Antilock Brakes / Traction Control Systems: Service Precautions

General Instructions/Safety Instructions

Danger of damage due to improper handling of batteries and control module plug connections.
- Never disconnect battery with engine running.
- Never start engine if battery terminal clamps are not connected securely.
- Never pull off or push on plug connections for the control modules or other electronic components when the ignition is switched on.
- Always disconnect the negative terminal of the battery and pull off all plug connections to the vehicle electrical system control module when carrying out welding work on the vehicle.

Danger of injury and damage as a result of the vehicle's unusual handling behaviour caused by disconnected plugs or components.
- Never disconnect plugs while driving or drive with them disconnected.
- Drive only with fully installed and connected parts.

Danger to life and limb while working on steering (releasing steering rod from steering gear) and on running gear (toe/ camber). The repair instructions must always be observed when carrying out repair work in the areas listed here.
- The battery must be disconnected before releasing the steering rod from the steering gear.
- When releasing the steering rod from the steering gear, make sure that the position of the steering wheel is not changed. Running gear locked or steering lock engaged.
- The steering-angle sensor must be recalibrated on the measuring platform each time the steering rod is released. The steering-angle sensor must be reinitialised whenever the power supply is interrupted (PSM indicator light comes on).
- After carrying out work on the running gear and steering, the spiral spring (airbag coil) must be centerd.

The following conditions must be met to ensure the faultless operation of the system:
- The battery terminal clamps must be secure.
- The brake fluid level must be at the correct level.
- The system must not leak.
- Tire size, air pressure and the condition of the tires must be satisfactory.

The following points must be observed during vehicle diagnosis:
- The steering-angle sensor must be initialised whenever the power supply is interrupted (PSM indicator light on).
- The steering-angle sensor must be recalibrated after all work on the running gear.
- After troubleshooting or repairs: Erase the fault memory using the Porsche System Tester II No. 9588 and carry out a test drive.
- Read out the fault memory again after the test drive.