Notes For Avoiding Damage To Ignition Systems During Testing

WARNING: This page is about a different car, the 1996 Mercedes-Benz C220, 1995 Mercedes-Benz C220, and 1994 Mercedes-Benz C220. However, it is still accessible from the selected car via links, so may be relevant.

To avoid damage to the control module, disconnect and connect control module connectors with the ignition switched OFF.
Do not connect a test lamp to circuit 1 or 15 of ignition coil.
Terminal 1 of the ignition coils must not be short-circuited to grounds, e.g. anti-theft protection.
Install only original ignition system components.
Do not operate the ignition system at cranking speed unless the ignition wires are fully connected.
The following ignition tests should NOT be performed with engine cranking or with the engine running: Holding secondary coil wire at a distance to ground, disconnecting a spark plug connector, or pulling secondary coil wore out of the ignition coil(s).
Each high voltage circuit must have a load of at least 2 kV (plug connector).
On the separate ignition coil tests, the ignition coil must not be loaded above 28 kV to avoid damaging the ignition coil.
If each cuts out when using engine analyzer during cylinder balance test, do not perform further testing with that type of engine analyzer.
If it is necessary to check the ignition spark following a breakdown, check with spark plug connected to one of the secondary ignition wires. Ensure that the spark plug is well grounded.
When working at cranking speed, e.g. checking compression, switch off ignition and: On engine with HFM-SFI/ME-SFI fuel injection and ignition system, disconnect connector "2" on control module.