Time to fix this stupid check light

[EtaSport]

On the overhead check panel. My brake check light is always on. But all of my brakes including the center light all work. Is the increased resistance from an older bulb enough to cause the check LED to light?

I have also seen the wiring diagrams for this, and saw that everything goes into a relay which is basically called the rear light check relay or something like that. Bentley says it is in trunk by the antenna but I can't see it anywhere. Does this thing actually exist? I'm putting money on something with this being bad, but does anyone have any input, similar experiences?

Ive had problems with these things before but it was for license plate lights even though they were working. (in an e28)

[bmwguru007]

Do all of your bulbs have a silver base? If not that is likely your problem.

[turnofftheradio]

Do all of your bulbs have a silver base? If not that is likely your problem.

what's that about? some corrosion issue? mine are gold base and f-up all the time. I just figured it was the backing plate not contacting well.

[RobertK]

I never understood how the brake light relay works either. My CEL always flashes when you start the car with the brake light LED lit on the check panel. As soon as I hit the brake pedal it turns off until I turn the car off and it back up.

[T.Dot E30]

I never understood how the brake light relay works either. My CEL always flashes when you start the car with the brake light LED lit on the check panel. As soon as I hit the brake pedal it turns off until I turn the car off and it back up.

That was the intention of the system, to check your brake lights to make sure all of em are working.
If one blub was out it wouldn't turn off when u tap the brake.

I've seen it happen to cars where the wrong blubs were used, with the wrong wattage. .

[Jordan]

The system is really quite simple, its just confusing until you realize how it works and whats inside the Check Control Relay.

First thing you should do, which is the cheapest. Replace all the bulbs in your tail lamp housings, and the 3rd brake light housings with new nickel base OSRAM bulbs. Autozone and the like only carry cheap ass bulbs. Don't use them.

Look for any signs of corrosion on the bulb holders, if there is any use a wire brush to remove it. Coat the bulb bases with a small amount of dielectric grease to keep corrosion from happening.

If the light is still on after this it is almost certainly the Check Control Relay that went faulty. Mine did, and I had a nagging "Rear Lights" light on just about all the time.

The box has 6 silent relays in it. The circuit powering the lamp itself flows through a coil. When power is going through the coil it closes the contacts of the check control circuit. When the relay grounds out the check control circuit the lights go off. if the bulb has burned out or has too much resistance the coil will not be able to close the contacts, and the light will be illuminated.

You can manually ground out each check control circuit (6 of them in main relay housing, 1 in 3rd brake light housing) to check for faults.

[EtaSport]

Well, I'm pretty sure I've got gold based lights, so I think i'll be searching for some new ones. Can I get them online or at a better place than the zone? They never have what I need anyway.

If it doesnt work, ill be going to the check relay. Is it really in the trunk like the bentley says? Thanks

[arsevader]

Well, I'm pretty sure I've got gold based lights, so I think i'll be searching for some new ones. Can I get them online or at a better place than the zone? They never have what I need anyway.

If it doesnt work, ill be going to the check relay. Is it really in the trunk like the bentley says? Thanks

If you can't get OSRAMs, GE makes silver based ones for "imports". I've bought these at parts places before.

[Jordan]

The Check Control Relay is attached to the same bracket as the premium sound amp, just behind the power antenna.

[RobertK]

I'm pretty sure I've got a set of el cheapo Auto Zone specials.. where can you usually pickup the OSRAMs and what the hell does OSRAM stand for?

[Jordan]

OSRAM is a company.