Mercedes-Benz W210 Lamp defective message
Why does the W210 show a Lamp defective message?
The most common cause is an oxidised or loose bulb socket or connector. Other causes are a bulb of the wrong wattage, a blown licence plate light, the light switch and a poor ground. The warning goes away when all the lighting works.
How do you find the cause of a Lamp defective message?
The circuit points the way: a message with the parking lights on points to the front, rear or licence plate lights, with the headlights on to the headlights, and when braking to the brake lights. Check the bulb type, the cleanliness of the sockets, the contact of the licence plate light and the fuses. The reversing lights must have 12 V 21 W bulbs.
Why does the front parking light not work even though there is voltage at the socket?
The grey wire of the parking bulb has a series resistor with a value of 2.5 ohms. If the resistor has burned out, the bulb does not light even though there is voltage at the socket. A more powerful 21 W bulb can burn the resistor. Use the original bulb type.
What should be done if the contacts oxidise in the rear lights?
The bulb sockets of the rear lights oxidise easily and the light comes on with a delay, which triggers the lamp monitoring. Clean the contact surfaces by sanding and treat them with copper paste. Also check that the metal part of the bulb is not loose.