My daughter has been driving our 2005 Lexus LS 430 while in college for the past year.

She recently said the Check VSC light came on so this weekend when she visited I pulled the code and it is Error Code P0756 - Shift Solenoid B Performance / Stuck Off.

I made a cursory check through the engine and underneath car since she had her brakes and rotors replaced the week before. I did find that the air filter housing clips were all left unclipped. I also reset the error code through my OBD2 diagnostic tool.

I took the car for a short drive and notice that the car jerks at around 55 mph. I noticed the Automatic transmission selector lever (PWR/ECT/SNO) was in the PWR mode so I switched it to ECT (normal) and the jerk was less severe.

I'm going to be taking the car in to a trusted and honest mechanic to have the timing belt/water pump changed Monday. I'm wondering if the P0756 code is due to too much or too little transmission fluid?

 

Call SIA electronics so they can repair the ECU, 99% of the time that is the issue

 

Interesting that this thread had only one response. The reason I am replying now, is that my indie garage asked me what if any codes were thrown with the hard downshifts. I had to search my photo gallery, and it was in fact P0756. I cleared it with the hopes that my "hard downshift" at 3-2 and 2-1 would go away, and it did not. The code never came back, but the hard downshifts persisted, until I sent the ECU out for repair, to the place mentioned in the previous threads.

Again, I'm replying in case this happens to someone else, hoping they'll avoid all the anxiety of feeling a transmission may be needed. It should be the ECU repair that fixes it.