Disabling 'Bulb Out' Light, 3rd Brake Light - Lamp Failure Module
#1
Disabling 'Bulb Out' Light, 3rd Brake Light - Lamp Failure Module
Well, I finally spent some time locating the Lamp Failure Module and trying to disable the 'Bulb Out" light on the dash. The Lamp Failure Module is found behind the left side panel in the trunk, underneath the left trunk lid hinge. You need to peel back the left trunk liner, then find the orangy-colored box that's bolted to the inside of the large trunk brace (see picture). This unit only has ONE OUTPUT, it indicates that either a tail, stop, or 3rd brake light bulb is out by sending a single signal to ECU #2. Once this signal is disconnected, no more bulb out indication. The output to the ECU is on pin 4 of the Lamp Failure Module (see arrow in picture).
So first I tried the electrical tape deal as outlined in the following thread:
https://www.clublexus.com/forums/sho...fully+disabled
but the connector pin kept puncturing the electrical tape when I re-assembled the connector and kept making contact anyway.
Then I figured the dang thing only has one output, so I disconnected it completely. No more bulb out light. Only one minor problem. No more tail lights or brake lights either. I drove for a whole day like this until a guy pulled up next to me and told me about it. I instantly knew what was wrong - the tail/brake light path runs THROUGH the Lamp Failure Module, and it needs to be connected to retain the light functions.
OK, time to get serious with this. I removed the unit from the car and opened it up, it comes apart very easily and is only 4 parts (see picture). I traced the Pin 4 output into the PC board and the last component the signal goes through is a resistor. I clipped the resistor (you can clip either end to disable), pulled one end up i the air, and reassembled. Bingo, no more bulb out light, and this time I still have tail & brake lights. Done.
So if anyone decides to do this, clip the resistor so that you can easily bend it back down and drop a ball of solder on it to reconnect it and restore normal operation, in case you're returning to stock config.
Sorry the pics aren't too clear, my digital camera wouldn't focus that close.
I'll bet that if we could get a more complete schematic of this board, we could figure out how to re-rig it so that the bulb out indication would work for whatever load/bulbs you put in the circuit just by changing the values of a couple of resistors.....
Jerry.
So first I tried the electrical tape deal as outlined in the following thread:
https://www.clublexus.com/forums/sho...fully+disabled
but the connector pin kept puncturing the electrical tape when I re-assembled the connector and kept making contact anyway.
Then I figured the dang thing only has one output, so I disconnected it completely. No more bulb out light. Only one minor problem. No more tail lights or brake lights either. I drove for a whole day like this until a guy pulled up next to me and told me about it. I instantly knew what was wrong - the tail/brake light path runs THROUGH the Lamp Failure Module, and it needs to be connected to retain the light functions.
OK, time to get serious with this. I removed the unit from the car and opened it up, it comes apart very easily and is only 4 parts (see picture). I traced the Pin 4 output into the PC board and the last component the signal goes through is a resistor. I clipped the resistor (you can clip either end to disable), pulled one end up i the air, and reassembled. Bingo, no more bulb out light, and this time I still have tail & brake lights. Done.
So if anyone decides to do this, clip the resistor so that you can easily bend it back down and drop a ball of solder on it to reconnect it and restore normal operation, in case you're returning to stock config.
Sorry the pics aren't too clear, my digital camera wouldn't focus that close.
I'll bet that if we could get a more complete schematic of this board, we could figure out how to re-rig it so that the bulb out indication would work for whatever load/bulbs you put in the circuit just by changing the values of a couple of resistors.....
Jerry.
Last edited by engin_ear; 05-18-05 at 08:05 PM.
#6
Originally Posted by PHML
Weird....i just pulled Pin #4 wire and lamp failure warning light was gone....but brake and taillights still work perfectly.
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#15
Lexus Fanatic
iTrader: (6)
sorry to bring back an old thread, but just wanted to say this mod must be 2nd easiest to replacing the bumper lights! i referenced an old thread and followed PHML's DIY to a 't'! i also pulled out my deck 3rd brake light so there's no bump and covered the big empty hole with some dark carpeting for concealment. wuala! poof!
i must hand it to CL...loads...tons of useful info!
i must hand it to CL...loads...tons of useful info!