Step C4

Checking the hood contact




- Ignition off.
Check that the magnet in the hood is correctly positioned, i.e. that the magnet is correctly polarised in relation to the switch, and also that the distance between the magnet and the switch is correct.

Checking the magnet's position with respect to the magnetic switch
- Remove the magnet from the hood.
- Connect an ohmmeter to the magnetic switch.
- Move the magnet gradually towards the switch.

If the reading correct:




If the gap is 5-12 mm the magnetic switch should be open, i.e. the ohmmeter should read infinite resistance.




If the gap is over 30 mm the magnetic switch should be closed, i.e. the ohmmeter should show approx 0 ohms (and there may be a buzzing sound).

If the reading deviates:




If, during the check, the ohmmeter shows no resistance, turn the magnet through 180 degrees and repeat the test.
- When the correct position for the magnet In relation to the switch has been found, mark both items to ensure correct assembly. Refix the magnet on the hood and reconnect the leads.

Checking the distance between the magnet and the switch




Place a lump of putty over the magnetic switch.
Close the hood.
- Open the hood and measure the gap In the putty between the magnet and the switch.
- If necessary, adjust the position of the magnet. At a distance of 5-12 mm, the magnet and switch should be exactly opposite each other.

At a distance of 2-4 mm, the switch should move 5 mm sideways (this is so that the magnetic fields in the contacts do not cancel each other out).

Note: The widest permissible gap is 12 mm.





- Close the hood.




- Connect an ohmmeter between ground and the alarm relay base item FH.
The ohmmeter should read infinity when the hood is closed.

If the reading is correct:
- Proceed to ohm test below.

If the reading deviates:
There is a fault on the hood contact.
- Renew the hood contact.
Replace the alarm control module.




- Open the hood.




- Connect an ohmmeter between ground and the alarm relay base item FH.
The ohmmeter should show approx. 0 ohms when the hood is open.

If the reading is correct:
There is most likely a fault in the alarm control module.
- Carry out fault tracing. Fault Tracing Alarm Wiring

If the reading deviates:
There is a fault in the hood contact.
- Renew the hood contact.
Replace the alarm control module.