Tepi

Hi everyone

At first sorry for my English spelling.

I'm from Finland
I work as a Toyota/Lexus mechanic.(But I have very little experience of Lexuses. They are quite rare in our area)

I have a problem with Lexus LS400 ,prod.date 04/98.

Every morning when I jump into the car and start to drive, I can drive as far as I want with no problems, but If I take a brake (engine is now in normal operating temperature) for example at the gas station and drink one cup of coffee.
And then, when I start the car again and continue driving it takes everytime approx. 30 seconds and VSC-OFF light and CHECK ENGINE comes on.
Now If I turn ignition off and start the engine, after 30 sec. same thing happens again. I don't feel anything when the light hits, everything seems to work fine except I can't use VSC-system.

But if I clear codes (P1346 and C1201) with OBD2-tester, I can drive no matter how many miles if I don't take a break and turn IGN off.

Code P1346: VVT Sensor/Camshaft Position Sensor Circuit Range/Performance Problem (Bank 1)

Code C1201: Engine control system. System malfunction

Factory book says reason for code P1346 is jumping teeth of timing belt or faulty ECU.
But I must be absolutely sure before I order new Very expensive ECU. I don't have a chance to test with another ECU.

I have changed the timing belt and tensioner.
I have measured resistances and checked wire harshness, everything seems to be okay (except I'm not sure about crankshaft position sensor, because I couldn't find reference value. I measured 2,1 kilo ohms. Cam pos. sensor and VVT sensors were aprox. 1,3 kohms)
I have changed places between VVT-sensors, but code stays in Bank1.
I have tried new Oil Control Valve for VVT in Bank1.
And I don't believe in any bad contacts because of the nature of malfunction, warm engine and TIME after re-start seems to be the main points.

Have you ever experienced this kind of problem ?
If you have any advice, please help me.

Thanks, Tepi