strongsail

DA51, got your PM, sent you a reply.

The earlier post from Nextlevelcoupe may be a place to look - - if the high-pressure hose from the TRAC pump to the accumulator is leaking, it could ingest air when the pump isn't running and fool the TRAC actuator into running too much, which would lead to fault code 54. Just a thought...here's a scan from the manual that shows the pump and accumulator:

DA51

Thanks for the photo. Yes, your'e right. That flexible hose has moisture on the outside and dirt.
How do I replace all the fluid and not damage the pump?

strongsail

I'd say take it to the dealer or a high-tech brake shop. Bleeding all the air out of all that plumbing is quite a process, according to the manual. Probably a Lexus dealer would be best, those O-rings must not be re-used, in fact if it's wet at the fittings that's all you may need, just O-rings - if you're going to have the fluid flushed & changed, get the leak fixed at the same time, have them reset the ecu and see if that solves your problems...

DA51

Could someone explain what TRAC code #43 covers? What faults should I be searching for? And what is the remedy?
Thanks for your effort.

mdfdsc300

are there other symptoms when the trac light comes on? Occasionally, when the trac light comes on during idle (off gas pedal), my engine stalls. Anyone have this problem?