Hello,
I have a 2006 Lexus GS430 with 170,000 miles on the dash. Car runs like an absolute dream except for one thing:
This is what happens:
Sometimes when I start the car the brake light comes on, and sometimes it comes on while I'm driving. Most times it turns off by itself, but other times it turns into a much more severe issue. I'll start the car, the brake light will come on and then the issue will mature into the "Check VSC" & "Check ECB" messages on the dash. Along with that, the traction control light, and ABS lights will come on, with, of course, the brake light. I have a picture of the errors but couldn't figure out how to attach it to this question. The most concerning part though, is that when this event occurs the brake pedal goes soft and I have to push the brake pedal a lot harder to get the same stopping effect. After a minute or two (maybe a few seconds), the errors disappear, and everything goes back to normal (including the brake pedal stiffness).
What has been done:
I took the car to my local Pep Boys and they said the rear brake pads were low so they changed them. They also checked the charging system and said it was fine. They said they also checked the brake systems and couldn't find any issues. The only thing they observed was that for one of the rear brakes (driver side) one of the retainer pins (pin that the brake pads slide on) had detached from the retainer spring and was sticking out of the system. They installed a new spring and that side looks normal now. This is a link to the retainer pins and spring I'm referring to ( https://www.amazon.com/ACDelco-18K1958X-Professional-Caliper-Hardware/dp/B004A551QE/ref=sr_1_2?dchild=1&keywords=lexus+gs+brake+hardware&qid=1620530568&sr=8-2 ).
After the Pep Boys visit the issue kept happening. I brought it back to them but they couldn't replicate the issue and also could not figure out why it kept happening so they gave up and told me I can pick up the car. I then found a Lexus dealer nearby and brought the vehicle to them. They had the car for 3 days and could not replicate the issue. I thought this would happen as the issue was intermittent for me. They also said there were no stored codes. After the 3rd day I gave up and picked up the car. The issue still happens after the Lexus dealership visit.
At this point I took to the internet. I went to the site http://www.justanswer.com (for $30) to see if anyone could answer my question about the issue. It was suggested that since I got the errors there should be stored codes in the computer. A buddy of mine has the Toyota Techstream software so I used it to run a full health check. The only stored code that came up was B2243 - Current Steering Angle Midpoint Unset. No other codes from any other ECU came up.
Additional Info:
The only non-stock things I changed on the vehicle are the lights and this USB module I installed.
All the lights on the car are now LED. The reason I did this is because when I bought the car the HIDs started becoming unreliable. One side would go off randomly. It annoyed me so I bypassed the headlight ballast and converted the headlights to LEDs. No issues with the headlights since then. After that, whatever bulb wasn't already stock LED, I converted to LED. All lights work perfectly. I also changed the flasher unit (under the the dash on driver side) for good measure.
I also installed a device that allows you to listen to music on a USB stick. I'm old school so I don't do streaming (which the vehicle does not support anyway). Basically, the module plugs into the back of the radio/navigation unit using a Y cable. The Y cable is necessary so that the navigation continues to work. So basically, the module acts as a DVD changer emulator. You can use the buttons on the steering wheel or head unit to skip to next or previous song and so on. The usb unit crashes sometimes, but it works fine most of the times. And by crash I mean that the song will stop playing and the head unit will either switch to radio, or mute and display "Radio off" (or something along those lines). To get it working again just requires me to unplug the USB module and plug back into the connector again. Here is a link to the USB module ( https://www.amazon.com/dp/B07C79XNKP/?coliid=IBM57VDIQAIEN&colid=3UY2AAA15UL0T&psc=1&ref_=lv_ov_lig_dp_it ).
Personally I think the additional info is unrelated to the issue, but I figured you never know.
Also, I do a lot of mechanical work myself, and will do it if It's something I feel comfortable doing. Please excuse any technical terms I used incorrectly though lol.
Well, that's all the detail I could think of. Can you help me pinpoint this issue?
Well you can unplug the USB stuff for a little while see if issue goes away but I doubt they are related. Sounds like you have a brake sensor, wheel speed sensor or abs module going bad or having intermittent connection issues. Like maybe the plug on one of them is corroded and having intermittent connection problems.
Quick update in case anyone sees this and has the same problem with this model. So it turns out the brake fluid was low. I waited until the error came back, and then scanned the computer. The code I got back was for the brake fluid level sensor. When I checked the reservoir, the fluid level was right at the sensor level. So, I topped off the fluid to the max line. Turns out for this model if the sensor error is tripped other errors are tripped, but the trouble code is not stored permanently. So you have to be having the problem for the code to be exposed. It's kind of trippy how the (2) shops I brought it to didn't check the fluid level. Anyway, the problem has not come back since and that was months ago.
Thank you for keeping us updated. I would definitely avoid a chain store like Pep Boys as well as the dealer. Isn’t there a good, independent mechanic that works on Japanese cars (especially Toyota/Lexus) in your area?
Have a pro mechanic check the ABS system with a high level scan tools.
