Vehicle Damage Warnings

Be sure the ignition is switched OFF, when:
^ Disconnecting ignition wires
^ Disconnecting fuel injection system wiring
^ Connecting or disconnecting test equipment leads
^ Disconnecting the battery
^ Washing the engine or engine compartment

BEFORE cranking the engine at starting RPM (such as for compression testing) disable the ignition and fuel injection systems:
^ Disconnect the ignition coil power output stage.
^ Disconnect harness connectors from all fuel injectors.
^ After the work is completed, erase Diagnostic Trouble Code (DTC) memory.

BEFORE disconnecting the battery:
^ Stop the engine.
^ Be sure the ignition is switched OFF (also applies when connecting the battery). Failure to do so may damage the Engine Control Module (ECM).
^ Be sure of the proper radio code (for vehicles equipped with coded anti-theft radio).

Be sure the battery negative (-) cable is disconnected, when:
^ Working on the electrical system
^ Resistance (spot) welding or electric arc welding anywhere on the vehicle.

When connecting and disconnecting electrical test equipment (LED voltage tester, multimeter, etc.):
^ Be sure the ignition is switched OFF.
^ Use correct adapters from the VW 1594 connector test kit For any work affecting the Engine Control Module (ECM):
^ BEFORE disconnecting the ECM harness connector, switch the ignition OFF and WAIT at least 30 seconds. Failure to do so may damage the ECM.
^ DO NOT connect any outside voltage source to stimulate an output signal at the ECM.