Glad I found this forum!! Just had the very same issue with 2006 IS 250 where engine started shuddering followed by VSE, CEL and TRC light on. Shuddering engine happens from time to time, without turning out VSE/CEL/TRC light until today, a raining day.
The service rep seemed to already know the existing problem, of course she did not tell me, and asked me to do diagnosis first for $200, then milk for more since my car is out of warranty,
What's the solution here from previous posts? Reset the lights and keep driving?
