# Warning bulb light **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [June 2, 2008, 5:11am UTC](https://community.cartalk.com/t/warning-bulb-light/14742 "2008-06-02T05:11:09Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![rjsings](https://avatars.discourse-cdn.com/v4/letter/r/b782af/32.png) [@rjsings](https://community.cartalk.com/u/rjsings)\ **Post date:** [June 2, 2008, 5:11am UTC](https://community.cartalk.com/t/warning-bulb-light/14742/1 "2008-06-02T05:11:09Z")
1999 Lexus Rx300 warning light check bulbs came on. Checked all bulbs found none that needed replacing. Now when I start my car the warning light goes out, until I step on the break pedal to shift the car and it comes back on. Any suggestion to elimate this ? ---
**Author:** ![Cougar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cougar/32/21348_2.png) [@Cougar](https://community.cartalk.com/u/Cougar)\ **Post date:** [June 2, 2008, 8:36am UTC](https://community.cartalk.com/t/warning-bulb-light/14742/2 "2008-06-02T08:36:13Z")
If you are talking about the brake warning light check the fluid level, it may be slightly low. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [June 2, 2008, 10:46am UTC](https://community.cartalk.com/t/warning-bulb-light/14742/3 "2008-06-02T10:46:27Z")
I am assuming that you are referring to a warning light that indicates a burned-out light bulb. Even though you have verified that all bulbs are working, I can tell you that this problem can occur if the bulbs are not all from the same manufacturer. These devices compare the current draw between pairs of bulbs on the same circuit, and even the extremely minor difference in current draw between bulbs made by two different manufacturers can be sufficient to trigger this warning. I found this to be true on a Volvo that I had years ago. A couple of weeks ago, the owner of a more contemporary Volvo came to this forum with the same problem that you are reporting, and I suggested that he make sure that the bulbs on each circuit are the same brand. He replaced one or two “good” bulbs that came from differing manufacturers, and he reported that his problem was solved. While I can’t guarantee that a Lexus “bulb burnout indicator” works exactly as the one on a Volvo does, but I would suggest that you follow my advice, and make sure that the bulbs on each circuit are from the same manufacturer. With any luck, it will also work for you. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [June 2, 2008, 2:46pm UTC](https://community.cartalk.com/t/warning-bulb-light/14742/4 "2008-06-02T14:46:14Z")
Also make sure the rear license plate lights work. if either of these are out, it will cause this warning light to come on. If all the rear lights are working, then the problem might be with the rear light out module. The module is located behind the left trunk panel. It’s a plastic box about the size of a pack of cigarettes. Unplug the module and remove it from the vehicle. Remove the cover from the module, and inspect the solid state circuit for any burnt components. If any are found, the module requires replacement. Tester ---
**Author:** ![rjsings](https://avatars.discourse-cdn.com/v4/letter/r/b782af/32.png) [@rjsings](https://community.cartalk.com/u/rjsings)\ **Post date:** [June 6, 2008, 9:24pm UTC](https://community.cartalk.com/t/warning-bulb-light/14742/5 "2008-06-06T21:24:41Z")
No this the warning light for burned out light bulb. ---
**Author:** ![rjsings](https://avatars.discourse-cdn.com/v4/letter/r/b782af/32.png) [@rjsings](https://community.cartalk.com/u/rjsings)\ **Post date:** [June 6, 2008, 9:29pm UTC](https://community.cartalk.com/t/warning-bulb-light/14742/6 "2008-06-06T21:29:19Z")
I have not changed any of the bulbs. I cannot understand when I start my car the warning like goes out, but you cannot shift the car unless you press the break pedal when I do that the light comes on and stay on. Thank for the info. ---
**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\ **Post date:** [June 6, 2008, 9:39pm UTC](https://community.cartalk.com/t/warning-bulb-light/14742/7 "2008-06-06T21:39:37Z")
The current draw through the brake light system is not measured until you step on the brake(completing the circut) the inital light on situation is probably a system check function. This bulb matching fact was known in the early 80s with BMW as they were one of the first if not the first with a bulb warning system ---
**Author:** ![JayWB](https://avatars.discourse-cdn.com/v4/letter/j/e480ec/32.png) [@JayWB](https://community.cartalk.com/u/JayWB)\ **Post date:** [June 7, 2008, 1:07am UTC](https://community.cartalk.com/t/warning-bulb-light/14742/8 "2008-06-07T01:07:48Z")
…"This bulb matching fact was known in the early 80s with BMW as they were one of the first if not the first with a bulb warning system " My '78 Yamaha had a failed lamp warning system. ---
**Author:** ![VDCdriver](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/vdcdriver/32/30_2.png) [@VDCdriver](https://community.cartalk.com/u/VDCdriver)\ **Post date:** [June 7, 2008, 11:17am UTC](https://community.cartalk.com/t/warning-bulb-light/14742/9 "2008-06-07T11:17:48Z")
My '74 Volvo had this system, and that is what I was referring to in my earlier post. BMW was clearly not the first.