RX300LMR

Thanks, ABS light is definitely not on, just the VSC. I'm bringing to AZ tonight to see if there are any new codes, I looked through the error code list and didn't recognize anything obviously relating to VSC, but we'll see what happens.

Thank, I will keep everyone posted. Tonight I'll try and swing by Autozone to read the codes (if any) since the light came on again this morning. I was a little encouraged yesterday when it stayed off as I started the car. Now it only comes on when the car is in gear and actually moving, so I'm anxious to see if there are any pending or current codes.

"....soon as I start to accelerate..." That would seemingly imply the accelerometer/yaw sensor module. There are only two sensors unique to VSC, the aforementioned and the stearing wheel rotational position sensor. Thanks for your response, now let me ask this please: Since the VSC light is on without the Check Engine light, will the computer still record an error code? Also, is the VSC controlled by the computer - meaning when we pulled the EFI fuse, should that have reset the VSC light?

After replacing A/F sensor yesterday, the VSC light is coming on by itself (No check engine light) when I start to drive. The EFI fuse was pulled and the CEL shut off, but the VSC light came right on and stayed on. Drove a few short trips last night and today and now when I start the car, stay in Park or even shift into 'Drive' the VSC light remains off, BUT as soon as I start to accelerate the light comes on within a few seconds. The CEL bulb is fine since it comes on during initial start-up. I checked the manual and can't find too much on it, other than take to the dealer...which won't be happening. Since it's changed a bit since yesterday, I was wondering if it may clear itself up after a few more key cycles or if anyone has any ideas?

Thank you so much for your reply, we tried the advice and checked the voltage on the sensor underneath the car that we thought was fine and sure enough, the heater circuit was OPEN. Due to the P0135 code it didn't occur to us that the lower one could be the problem. We put the new OEM one under the car and put the original factory sensor back in place near the exhaust manifold, pulled the EFI fuse and now the Check Engine Light finally shut off! I am relieved to say the least, but now the VSC light is on by itself - any thoughts as to why? Checked the brake fluid and it's just above the min line but that is an easy fix. I couldn't find any posts about VSC only light being on without the CEL. Anyone know if I can pass inspection with the VSC light on - or will it shut off on it's own? Can't thank you enough for taking the time to reply, I really appreciate it - and have a great holiday!

At 65,000 miles my VSC/CEL lights stayed on so I had local Auto Zone read codes, 1st was P0135 for O2 Bank 1 Sensor 1. So to confirm the troubleshooting we swapped out with 2nd front sensor under the car and brought back to AZ again and sure enough, code changed to P0136 for Bank 1 Sensor 2. Conclusion was a new sensor was needed so we bought the Denso universal, soldered and replaced original front sensor. Went back to reset at AAP and of course it still throws the P0135 code. Knowledgable manager at AAP said universal wasn't wide band and maybe that could be my problem, so I bought a Bosch wideband replacement sensor. Went through the same ritual, reset and it still throws the same code and lights stay on. Meanwhile, my mpg hasn't changed and car still running fine. Called a few Lexus dealers and they said only the original Denso A/F Sensor #89467-48011 would shut off the CEL/VSC lights. So I picked up the part from the local Lexus dealer($211) and swapped out Sensor 1, disconnected the battery for an hour and lights came back on. I couldn't find the thread with the fuse trick but I will try that too. Today we brought back to AAP and reset using the scan tool, but sure enough lights came right back on, again throwing P0135 code. Needless to say I'm very discouraged since I was hoping to avoid giving the dealer another $150+ just to use their scan tool. Any thoughts as to what to try next? NH has emissions so I can't pass inspection. I welcome and appreciate any advice. I've spent many hours researching on this particular forum and was surprised to see many peo w/same problem at similar mileage, but I can't seem to find out the next step. Thanks.