Computers and Control Systems: Service Precautions

IMPORTANT CAR INFORMATION

Conformance with following safety measures is necessary to avoid damaging the electronic ignition system.

1. Never start engine without a firmly connected battery.

2. Mixing up power supply connections, e.g. wrong connection of battery, could lead to destruction of the control units.

3. Never disconnect battery while engine is running.

4. Never use a boost battery charger to start the engine. Only use a second 12 V battery with jump leads.

5. Disconnect battery from car network before boost charging.

6. Only measure resistance values after turning off ignition or disconnecting battery.

7. Pull off both control unit plugs or make a firm connection between ignition coil ter. 4 and ground with a cable before checking the compression (dangerous high voltage, insulation damage to ignition coil, high voltage distributor, ignition cables, etc.). Cable must be interference suppressed with a shielding sleeve of at least 2 kohms.

8. When testing the compression of cars with catalytic converters, always disconnect the fuel-pump relay.

9. Never replace specified ignition coil with a different ignition coil.

10. Never connect a shielded capacitor on ignition coil terminals 1 and 15.

11. Ignition coil terminal 1 must not be used for ground connection when installing a burglar alarm system (ignition coil would be destroyed when key was turned to "ignition on").

12. Never connect battery positive (+) or a test lamp to ignition coil terminal 1.

13. Never disconnect ignition lead between ignition coil terminal 4 and high voltage distributor terminal 4 while engine is running.

14. To avoid destruction of the ignition control unit, secondary side of ignition system must be shielded with at least 4 kohms, whereby the original distributor rotor with a 1 kohm shielded resistor must be installed (do not use a 5 kohm distributor rotor even for radio and communication equipment suppression).