Safety precautions

WARNING: This page is about a different car, the 2009 Audi A4, 2008 Audi A4, 2007 Audi A4, 2006 Audi A4, and 2005 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Fuel system is under high pressure! Before opening high pressure components of the fuel injection system, pressure must be relieved to residual pressure → Procedure that must be performed before opening the high-pressure fuel injection system - Pay close attention! . Then wrap a clean rag around the connection and relieve residual pressure by carefully loosening the connection.

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

The ignition must be switched off before connecting or disconnecting injection and ignition system wiring or tester cables.
It is possible that the control module will recognize a malfunction and store a DTC during some tests. Therefore, when all tests and repairs are completed, the DTC memory must be checked and, if necessary, erased. After DTC memory is erased, a readiness code must be generated for engine control module using operating mode "Guided Fault Finding".
Clean engine only with ignition switched off.

CAUTION:

The battery must only be disconnected and connected with the ignition switched off, since the Engine Control Module (ECM) can otherwise be damaged.
Observe safety precautions when disconnecting the battery → 27 BATTERY, STARTER, GENERATOR, CRUISE CONTROL .