How to modify the tail lights failure sensor for UCF20/21
#33
Moderator
Thread Starter
As long as I have modified JDMs, all worked well lifting the 2.2K at the corner.
The best method is to change those 3 current sensing resistors (3 metal parts) selecting to meet the LEDs current. But this is a time consuming job. The actual methods is to use a high-wattage variable resistor and find resistors which work well with your LED lights.
Another method may be to cut the trace to pin #4 of the connector but I have never tried it. Theoretically it should work.
The best method is to change those 3 current sensing resistors (3 metal parts) selecting to meet the LEDs current. But this is a time consuming job. The actual methods is to use a high-wattage variable resistor and find resistors which work well with your LED lights.
Another method may be to cut the trace to pin #4 of the connector but I have never tried it. Theoretically it should work.
Last edited by Yamae; 10-21-14 at 08:40 PM. Reason: Correction of pin number.
#36
Moderator
Thread Starter
#37
Me and schmee have the same tail lights so it's nice to know it wasn't just my car.
So cutting number 4, Is that still from the red box inside the trunk? Do I just get needle nose pliers and pluck it out?
So cutting number 4, Is that still from the red box inside the trunk? Do I just get needle nose pliers and pluck it out?
#40
Moderator
Thread Starter
All you need to do is a reverse engineering by your eyes, skills, assumptions and efforts.
#41
Moderator
Thread Starter
I can give you some of the results of my reverse engineering.
The tail lights are checked by the current from pin5 to 7 and 11.
The brake lights, pin10 to 1 and 2.
The center brake light,pin 9 to 6.
The tail lights are checked by the current from pin5 to 7 and 11.
The brake lights, pin10 to 1 and 2.
The center brake light,pin 9 to 6.
#42
Moderator
Thread Starter
If you want to keep the unit alive with LED lights, you need to select proper resistors between those pins above. The simple way is to use a high wattage variable resistor or to do calculations of ratio and change to new higher resistors. The calculation is done like this below.
Original current / LED current X original resistance.
Usually, it is between 5 to 23 times depending on LEDs and circuit designs.
My result was 22.7 times. May be because I used special high efficiency LEDs for industrial use mounted on a white aluminum board and the unit is shaped like a regular bulb like this below. I aimed a direct replacement and the result was like the second photo. The photo was taken under the sun but lights were bright enough. The brightness is as same as the original and no one noticies that the LEDs are inside. I aimed to reduce the current and to pass the Shaken or the inspection by the government.
#43
Lexus Test Driver
iTrader: (3)
On my car (96), it is my brake lights triggering the dash light. i have checked and i have 3 resistor packs out of 6 that are bulged and cracked in the epoxy covering them so i would imagine this is the reason why i suddenly have this issue were it did not exist before.
So, if my understanding is right, you are suggesting i pull/clip the leads to pin 1,2&10?
#44
Moderator
iTrader: (7)
For which years?
On my car (96), it is my brake lights triggering the dash light. i have checked and i have 3 resistor packs out of 6 that are bulged and cracked in the epoxy covering them so i would imagine this is the reason why i suddenly have this issue were it did not exist before.
So, if my understanding is right, you are suggesting i pull/clip the leads to pin 1,2&10?
On my car (96), it is my brake lights triggering the dash light. i have checked and i have 3 resistor packs out of 6 that are bulged and cracked in the epoxy covering them so i would imagine this is the reason why i suddenly have this issue were it did not exist before.
So, if my understanding is right, you are suggesting i pull/clip the leads to pin 1,2&10?
on VWs i recall all i did was bend the pin flat as to not make contact on their headlight switch to disable DRLs. maybe that method can work here as well. like this:
#45
Driver School Candidate
Join Date: Nov 2012
Location: VA
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
2002 Lexus LS430 Tail Light Failure Alert
I have 2002 LS430, I have same problem with "Tail Light Failure". All bulbs are checked and three replaced. No failure indicator unless I put in DRIVE mode (reverse or forward). The "Tail Light Failure" light comes on as soon as I put in Drive.
Please advise.
Please advise.