aarpm

Hi,

My 2001 LS430 is behaving strangely since last service. Ever so often, under completely safe and normal driving conditions, without any apparent reason the VSC goes into panic mode with "beep beep beep ..." and the light flashing. The beep and flash is occasionally accompanied with automatic braking and goes away on it's own in a few seconds. But generally I have to brake hard to settle it down, even if I'm driving at around 30 mph to start with. Turning the VSC off and back on also solves the problem, but only for that instance.

I got my brake pads replaced during last service. Could that have caused some problem? Also, the car isn't setting any error code for this problem. I got a scan done and there weren't any issues except for P1651 (VSV For ACIS Circuit Malfunction) which I have been getting for some time.

Would really appreciate any insights on what could possibly be going wrong.

Thanks a ton!

StanVanDam

Possible culprits are: front/rear left/right wheel speed sensors, skid control ECU (inside driver-side dash), steering angle sensor (inside the steering wheel), yaw rate sensor (under and behind the gear shift), and/or the brake pedal load sensing switch (above the brake pedal)

When they replaced the brake pads, perhaps they damaged the wheel speed sensor or the wiring/connector for the wheel speed sensor. I would take it back to them and say that your VSC was fine before, but started acting up after the brake service and that maybe a harness was dislodged.

See if they will go for a drive with the car plugged into a Techstream laptop, so they can see which sensors are being activated when the VSC engages.

EDIT: If the sensors are connected and working, try a zero-point calibration of the sensors. You'll need a Lexus tool to do this.

svlexus

Yup

aarpm

Thanks StanVanDam! That's a ton of help.

I went back to the workshop, had him open up the brakes, check the sensors, clean and put them back. So far so good. The problem hasn't reoccurred.