1. Disconnect the negative battery terminal and wait at least one minute.
2. Remove the driver's side airbag module.
3. Disconnect the contact disk connector.
4. Using a tester, measure the resistance between terminals E and A of the contact disk.
If the measured values are not correct, replace the steering switch.
5. Apply battery voltage to terminal F of the contact disk (wiring side connector), and output B (wiring side connector) connect with mass.
6. Verify that the LED lights up. If the LED does not illuminate, replace the steering switch.