Safety precautions

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

Do not touch or disconnect ignition wiring when the engine is running or being turned at starter speed.
The ignition must be switched off before disconnecting or connecting ignition system wiring and high-voltage cables for test instruments.
In order to run the engine at starting speed without actually starting it (for example, to test compression), unplug the connectors on the ignition coils and also the connectors on the injectors.
During some of the tests the control module may identify and record faults. The Diagnostic Trouble Code (DTC) memory should therefore be checked and (if necessary) erased after completing the tests and any repair work that may be required. Generate readiness code after erasing Diagnostic Trouble Code (DTC) memory. Refer to Generate readiness code