Po715, Po763, P1349 Help!

[MsGS400]

I have a 98 GS 400 and my check engine, vsc and vsc off lamps are all on. When the lights first came on, the engine had a rough idle while at a red light. I turned the car off and on and it drove fine, 2 days later the codes cleared. While driving again...the codes reappeared...my car was a bit sluggish but it had no problem doing freeway speeds and driving around town.

I finally took the car to the Lexus dealer and they pulled codes P0715 - Input Speed sensor circut, P0763 - Shift solenoid C (#3) electrical and P1349 - VVT System Malfunction Bank 1. The dealer wants to charge me upwards of $500 to pull the transmission pan just to check the transmission.....IF it is the transmission. The car has been running good. Recently Lexus changed:

Entire Throttle Body

Altinator

Solenoid #1

Power Steering Pump

Resealed Gaskets

Transmission Fluid Flush

In addition, I had the Brake Booster replaced, new starter, Emergency brake assymbly and new tires.

I don't want to shell out unneccessary dollars to the dealer if this is a minor fix. Help!

[MsGS400]

Can someone please help?

[James Horning]

If the mileage is high my first thought is the wiring has become dried out and brittle and with all the previous work poor connection and broken connectors is where I would start.

The P0715 and P0763 look at the harness plug in to the transmission ( for the valve body ) for corrosion.

The P1349, OCV connection first , ( w/r and blue/black) .

Or blockage in oil control valve, remove and clean.

Check valve timing ( was timing belt just done)??

Check ECM connections for loose or corrosion -- wiggle test.

Make sure battery cables are perfect, no voltage drops no corrosion and no stupid *BLEEP*.

Make sure all ground on intake manifold are intact and perfect.

I really hope this helps none of these problems are " typical".