Hello! Ive had this problem for a while now, and i now have time for it. The code that my car is giving is #42, for the No. 1 speed sensor. I always have my overdrive off because of this, but whats strange is my check engine light randomly goes on an off, during drives with no relation to anything i am doing. It can be off an entire 6hr drive and only come on during the last 30 min, and be off next day, or vice versa. Does anyone know what would be causing these issues?

My speedometer has also become less accurate over the past month or two, but this vss light has been on for ~6 months

Thanks anyone for your help

p.s i have already ordered and plan to replace the sensor itself, but i want to see if the problem is something else

Your instrument cluster is probably failing causing the speed signal to be degraded. And it's very possible the engine computer has leaking capacitors. I'll be curious to see if a new speed sensor fixes your problem in that case my diagnosis will be wrong.

Well, a bad ECU would explain the random engine light. If that is the problem, could I just buy and replace the ECU? I know the dealership will charge an arm and a leg, but is there just somewhere I can buy a reliable one? I'm usually pretty *** at soldering so I don't want to mess with mine myself.

Forgot to update this. If anyone else had the same issues, I had the classic LS400 ECU & Gauge Cluster capacitor leak. I sent my ECU to the lexpert, and he fixed it for a few hundred bucks.

and this resolved all your issues? glad it was that simple.

Yes it did Theres a similiar capacitor leak in the instrument cluster, but ive just been using waze as I dont feel like paying to fix it rn