Safety precautions

Note the following points if testers and measuring instruments have to be used during a test drive:

CAUTION:

Proceed as follows to avoid the danger of accident during measurement and test drives:
Exclusive use is to be made for reading out measured value blocks of VAS 5051 or V.A.G 1551. Always attach the unit to the back seat and have a second person operate them from there.
Deactivate passenger airbag by means of button switch in glove box or by way of On Board Diagnostic (OBD). See appropriate Air Bag Restraint Systems article.
Front passenger airbag is to be reactivated on completion of work.

To prevent injuries to persons and/or damage to the fuel injection and ignition system, the following must be noted:

Always switch off the ignition before connecting or disconnecting measuring instruments and testers.
In the case of some tests, a DTC may be recognized and stored by the control module. At the end of all tests and repairs, the DTC memory should be checked and, if necessary, erased.
CAUTION: On vehicles equipped with Audi Telematics by OnStar(R), switch-off the emergency (back-up) battery for the Telematic/Telephone Control Module prior to disconnecting the vehicle battery. See EXAMPLE: SWITCH OFF EMERGENCY (BACK-UP) BATTERY . Switch-on the emergency (back-up) battery after reconnecting the vehicle battery. See EXAMPLE: SWITCH ON EMERGENCY (BACK-UP) BATTERY .
Always switch off the ignition before connecting or disconnecting the battery, otherwise the engine control module may be damaged.