A FAW Volkswagen Teng 1.8TS1 car with a mileage of about 120 thousand km in 2008. Users reflect that the steering wheel warning lights are lighted regularly while driving, while the steering lights, loudspeakers, wipers and dimming switches are invalid. The engine failure will disappear after the flameout. Inspection and analysis: maintenance personnel detect steering column control unit, no failure code. But from the gateway list, we can see that the steering column control unit has an impossible record. Check the fuse of the steering column control unit. The ignition switch of the vehicle is pushed into it, and the micro switch in its slot is used to control the power supply of the steering column control unit J527. When the engine idling, the car keys sway slightly in the slot, and the fault reappears. This indicates that the micro switch in the ignition switch slot is unstable. Troubleshooting: replace ignition switch assembly and troubleshooting.