VW Sharan Engine Speed Sensor (G28)

Hello,

I bought a Sharan with engine damage. The previous owner had a new engine installed, and instead of the original AUY engine, an ASZ engine was put in.

The next owner then tried to overhaul the engine and bought bearing shells for an AUY engine, which were, of course, too small. As a result, the crankshaft was damaged.

I then bought and installed a water pump (for an ASZ engine).

Okay, I've assembled everything and started it up. The engine runs perfectly at idle, but as soon as you give it any throttle, it starts to sputter and then dies.

The error log then showed the following:
16705 - Motor speed sensor (G28): implausible signal.

P0321 - 35-10 - - - Intermittent.

I then bought a new sensor for the AUY engine. However, this only brought a slight improvement. Now, when I press the accelerator, the engine doesn't shut off, but the RPMs rapidly fluctuate between 1500 and below 800, constantly and very quickly.

What do you think it could be? The same error code is stored in the error memory.

Should I buy a new sensor for the ASZ engine again?

or is something else broken?

Sure, no problem! Here's the translation:

"Thank you in advance!"

I suspect that the speed sensor ring has been bent during the repair process. To be sure, I would check the sensor signal using an oscilloscope. You could also remove the oil pan, measure the clearances, and bend the sensor wheel back into shape.
There are no differences in the throttle position sensor itself, only different connector types (old and new).

Okay, thanks. I'll go ahead and lower the tub and take a closer look at the wheel and the clearances.

It has an automatic transmission, which uses a sensor on the engine to determine the engine speed.

So, the oil pan had a "tooth" at the bottom that was bent about 1mm backwards, so I straightened it out.

There were two small chips on the sensor itself, which I removed.


Unfortunately, that didn't change the error message/behavior.


Today I was at VW, and the sensors for the AUY and ASZ engines have different part numbers. I've now ordered another ASZ sensor.

Okay, so I picked up the ASZ sensor today (the part number ends in "E" instead of "F" like the AUY, but it looks the same).

Installed it, and it works perfectly, running smoothly!