After reading your post I had very similar issues with my 2002 LX470. It has over 270K miles and mechanically it is still a beast. I love this truck, it was my wife's daily driver until it started acting up. Because it was so reliable it kept me at ease when she and my kids were on the road. However, about 10 months ago, the VSC sytem started activating randomly, sometimes while going 20 mph or three times at 65 mph! Very scary and very dangerous. Took it to several shops, including Lexus, and got multiple suggestions of what they "thought" the problem was, however, none of them registered any errors when plugged into the vehicles computer? When the system VSC activated, the brakes began to pump feverishly, and the entire dash lit up like a Christmas tree and steering was almost uncontrollable until our speed slowed to about 15 mph! After the various diagnosis and suggestions from different mechanics, I chased all the "cheap" fixes first, I.e., wheel speed sensors, getting a wheel alignment, even bought new tires, none of that solved the problem.

So I parked it while I researched some more. Finally, a church member had me take it to his guy and he found out that it was my Rack & Pinion system that was shot. It was leaking fluid in the boot, however, since there was no fliuds dripping under the car when parked it was never checked, I guess, because none of the shops ever mentioned it, especially Lexus! It was $135 diagnostic fee to tell me they didn't find any problems!

So I started researching part prices. An aftermarket part for the Rack & Pinion runs about $240.00. The OEM part from Toyota costs about $750.00! It was also recommend that I replace the tie rods on each side of the vehicle. So I replaced the inner and outer Tie Rods. Aftermarket parts for those run roughly $85 to $100.00 dollars. OEM parts from Toyota cost about $450.00.

So, I paid roughly $1600 dollars for parts and labor to fix the problem, including a wheel alignment. I bought the OEM Rack & Pinion part ($730) and aftermarket tie rods ($90). If you're a do-it-yourself type person, you can save a lot of money.

So, in summary, I replaced the wheel speed sensors, (aftermarket $75 for a pair) the OEM Rack & Pinion ($730), and the aftermarket inner and outer tie rods ($90). In hindsight, the rack & pinion, and tie rods plus the alignment were all that I needed, but Iwanted to be sure the problem was fixed! I have put roughly 600 miles on the vehicle since the repairs were done, and no issues! It's like she is brand new again! I hope this long explaination helps! I'm so glad to have my girl back! Gas prices right now are a different story! Lol

 

I have the same problem on my LX470. Shop is suggesting ECU replacement. Did that work for you?

 

In my case, I did not replace the ECU module. Just the Rack & Pinion, inner and outer tie rods, and got a wheel alignment. It has been roughly 2500 miles post-repair and no issues.

 

Thank you for this! My LX470 issue is more similar to dasgeek's as it only happen in a right hand tilt situation. I am glad what you did worked. $1600 is cheaper than the $2500 (not a terrible price for an ECU replace, I know) my shop is suggesting. Just don't want to replace the wrong thing. Both avenues are not inexpensive. I would hate to choose the wrong path and end up paying for both!

 

I completely understand! What I also failed to mention is that my VSC issue first triggered while making a left lane change. However, on other occasions, it didn't matter. One time while driving in a straight line on the open highway? I very much considered replacing the ECU as suggested by a few mechanics. However, when I stepped back and analyzed what was happening, the ECU unit IS working. If the system alerts you on right-hand angled curves, it is working. I'd bet it is your tie rods on that side are shot, I would also check the rack & pinion. I know it is a tough call and a lot of money is on the line but given all I learned during my ordeal,, I'd bet it is not electronic. Good luck