General Instructions/Safety Measures
· Never connect or disconnect the wiring harness plug to/from the engine control unit or other electronic components with the ignition switched on.
· For the compression check, disconnect the line from the fuel cutoff solenoid valve.
· Never start the engine if the battery is not firmly connected.
· Disconnect battery from vehicle electrical supply before charging or quick-charging.
· Never disconnect the battery from the vehicle electrical supply with the engine running.
· Never use the quick charger for starting.
· Control units must be removed before welding.
· At temperatures above 80 °C/176 °F (e.g. drying oven), control units must be removed.
· Use only high-resistance voltage testers for checking.
· For test steps in which connection contacts of wiring harness plugs or control units are to be connected to ground or battery voltage (+12 V), proceed with utmost care and concentration. An incorrectly selected contact can lead to destruction of internal circuits in the control units in question.
· After reconnecting the battery, volatile memories must be reprogrammed. With radio coding and station programming, inform the customer about the decoding and the deleted station memories.
· If the engine or the automatic transmission have been removed, ensure that all ground connections have been correctly connected after installation. If the engine is started despite a loose ground connection, this can cause damage to or destruction of the control unit.