If test and measuring equipment is required during road test, note the following:

WARNING: This page is about a different variant/trim than selected.

CAUTION:

Test and measuring equipment must always be secured to the rear seat and be operated from there by a second person.
If test and measuring instruments are operated from the front passenger s seat and the vehicle is involved in an accident, there is a possibility that the person sitting in this seat may receive serious injuries when the airbag is triggered.

To reduce the risk of personal injury and/or damage to the fuel injection and ignition system, always observe the following:

Only disconnect and reconnect wires for injection and ignition system, including test leads, if ignition is turned off.
If engine is to be cranked at starting RPM without starting (e.g. for compression testing), disconnect connectors from power output stages for ignition coils and remove fuse for fuel injectors. Electrical Wiring Diagrams, Troubleshooting and Component Locations
During some checks it is possible that the Engine Control Module (ECM) will detect and store a fault. Therefore after completing all checks and repairs the DTC memory of both engine control modules must be checked and, if necessary, erased.
Only clean the engine with the ignition switched off.

Only disconnect and connect the battery with the ignition switched off, since the ECMs can otherwise be damaged.

CAUTION: Fuel system is under pressure! Before loosening hose connections or opening the test connection (for fuel pressure testing), place rags around the connection area. Then release pressure by carefully loosening the connection.