Hello,
I have an RX 450h F-Sport (late year 2012 variant) with about 122000km on the clock, and I have started getting that error in the dashboard as well. Took the car to Lexus dealership and they said that it's corrosion damage since the two computers (one for each axle's stabilizer) are placed on the underside of the car, near the rear end, and therefore are getting more than their share of the salt water bath on the roads. Then they continued to announce that both of these computers need replacement and their price would be 12500e. Of course, both computers don't generally break at once so most likely the issue is on the several points where a cable connects to these computers. I took the car to my trusted maintenance guys and indeed it turns out that there is a bunch of light green/blue sludge on the connectors themselves, not just the typical mesh corrosion like with the rear electric motor power cable connector in RAV4's.
Whether you replace the computers or the set of related cables, the bill easily goes into thousands of euros. I have not gotten mine fixed yet as I'm looking for a repair shop where they have dealt with similar issues, because it's possible to just fix the connectors that are by far the most prone to corrosion. It's not fully clear to me yet if the whole set of cables would need to be replaced because there appears to be some cable-to-cable connectors there as well. The official dealerships always want to replace the whole component sets for their ridiculous prices even if the problem was only in one connector. Without physical damage to the protective layer of the cables, generally speaking, the only part in the cables/harness that would ever become a problem are these relatively exposed connectors on the underside of the car, so do your maintenance elsewhere. Here in Finland, Lexus charges 188 euros per hour and of course also the prices of their genuine parts are insane. So even if there was a need to construct a custom connector for the cables in the DIY style, it would still be much cheaper to pay a good specialized mechanic to do just that, instead of tearing apart half of the car to replace the whole set of cables, let alone replacing the computers with the processing power of a traditional pocket calculator, for the price of 5 RTX 5090's.
During summer, I noticed the car being surprisingly stable when doing corners at a high speed, and only afterwards I learned that my car has the active stabilizers. Haven't had the chance to test if I could notice a difference now that the error appeared and neither stabilizer is doing their work. I was told that this shouldn't affect the stability control system and it would mostly just be a problem in the mandatory inspections, even though at least in normal usage, there is little difference in how the car behaves.
If anyone has dealt with this issue and has more knowledge, sharing would be much appreciated.
Cheers
