Search the LED bulbs threads, there are a few that outline where they go and what type were used.

My understanding is that the older incandescent bulbs have a much higher resistance that the ECM/PCM reads as OK. When you install an LED in the circuit that resistance changes and throws the system codes (such as the light indicators). Certain (more expensive) LED lights are direct replacements and have the circuitry to act just like a normal incandescent bulb.

Need help understanding why brake lights dont work
 

Hi Guys
Just fitted a set of JDM led taillights. I now have a ABS & Traction light on. I have ordered a resistor that i'm going to fit onto the middle brake light wiring that should sort the problem out.


Unfortunately I put a new bulb in the middle brake light yesterday because I noticed it had gone. I tested the light and it still didn't work. I then found a thread about the wires being flayed and broken due to the way the boot closes.


Low and behold there was a wire broken, I have now reconnected the broken wire.


The trouble now is I put my lights on, the JDM's & lights came on, then the JDM's went off.


Yet my middle brake light and JDM brake lights work.....


Why does my JDM parking lights do not work?????? is it because I havnt put my resistor on yet???


Any advice

Hello Team - first up great discussion and thanks to those who made a useful contribution.

I have been using LED lights for 3 years years for both indicator and brake lights and with an update to my flasher module (I changed a resistor in there). So I got the indicator flash rate correct without having to add resistors. No issues with the ABS or TCS light in this configuration.

BUT then I bought the JDM rear light module (Search JDM RX8 Rear LED in Ebay) just like Jame5hill and bugger, the ABS and TCS lights came on! I tried all the bits in this forum (steering wheel, check fuse) and the only one that worked was to install a resistor on ONE of the rear light brake lines.

Team note it must be the brake line as the ABS circuit (and cruise control) relies on current sensing to know you are using the brakes (or not).

The JDM lights I bought are too low in current to work so you need to add a resistor. Without realizing it the red LED lights I had in there for my old light cluster had internal LEDs that were drawing enough current.

Where to add it? If you have a center light on the boot then YES that is the best place. Otherwise you have to splice into the left or right brake line. Note I have an LED boot light so those that have the old light and it works the ABS/TCS light should not come on.

What value to resistor add? 6-8 ohm 50 Watt is the generic answer. Yes those that try ohms law would recommend 25 Ohm 10 watt, which means less heat but most LED suppliers recommend the hotter 6-8 ohm 50 watt as this pretty much guarantees your circuit will work. I have tried both on the center light then I tried it on one of the rear lights (right hand side) and either resistor value works fine on any light. You only need one resistor if you have a JDM cluster.

Hope this helps - for me - the new JDM light module looks awesome for my 12 year old RX-8 but without a resistor (or at least an old brake light bulb in circuit), your ABS and TCS light will come on!

Martin

forgot to add

You have to put the resistor across the brake line and the ground line (parallel)

Martin

I've fix the problem. Tried everything mentioned in forum. End up the problem come from driver side (right) wheel hub faulty. Everything is good now after 3 months now.

I know I'm a couple years late on this thread but if get two new LED brake light housing (brake light/ blinker) but keep the third brake light, the one in the middle stock bulb no LED I won't need to get a resistor? The ABS lights won't come on as well?

ABS/TCS Lights come on intermittently
 

So a while back, my TCS and ABS lights randomly came on without any warning. Sometimes I turned the car on, and there would be no lights, but I'd drive a little bit and they would turn right back on.
I started to notice that my ABS system was activating at lower speeds when braking and it would turn my steering wheel to the right, showing that it was braking much harder on the front/passenger side.

I took it to a mechanic that I knew and used his scan tool to see what the issue was and it turned out to be my front/passenger wheel speed sensor was reading incorrectly. We looked at the graphs and it would should all the other wheels moving at a consistent speed over time, but the front-passenger side would dip sharply for a split second, then go back to normal.

The first thing I did was check all the wiring as far up as I could and see if any of the wires were compromised. All looked perfectly fine. Next, I decided to try and replace the wheel speed sensor. Nothing changed, exact same problem. Ok, so then my next option was that it could also be the wheel hub assembly that is having problems reading the correct speed of the wheel. We replaced it with this one from RockAuto, ( TIMKENHA590096{#F1513304X} ). Again, absolutely no change. I also read in a few places that the third brake light could be out and causing that problem. I flipped the trunk up and looked in my car and the light still works.

Does anyone else have any other ideas on what could possibly be wrong and causing the problem? Thank you for the help ( first post btw ). :wavey: