Touran Crankshaft Position Sensor - Faulty Signal

Good day, I am experiencing the following problem with a VW Touran manufactured in 2004, engine code "AVQ", 1.9 TDI, 74 kW.

The engine simply stopped while driving, and the following error code appeared in the diagnostic memory:


Address 01: Engine Control Module
Label file: DRV\03G-906-016-BKC.clb
Control unit part number: 03G 906 016 BT. Hardware version: 028 101 073 1.
Component and/or version: R4 1.9L EDC G200SG 7210.
Encoding: 0000072
Company number: WSC 50946 124 08326
text
VCID: 76E858BC01DB79F6BB-8022
"One error found:"

16706 - Motor speed sensor (G28).
P0322 - 000 - No signal - Warning light ON.
Environmental conditions:
Speed: 0 RPM.
Torque: 78.0 Nm
Speed: 0.0 km/h
Last: 0.0%
Voltage: 9.65 V
Binary value: 00001100
Idle stabilization: 0.0° KW.
Speed: 84 revolutions per minute.

Occasionally, an "implausible signal" was also detected.

I then checked the sensor data blocks from the G28 (engine speed sensor) and G40 (crankshaft position sensor). When attempting to start, G28 remains at "0", while G40 shows plausible values (see attached log file).

After approximately ten seconds of starting attempts, the engine starts, and the main control unit (MWB) displays a speed signal for the G28. (I am now assuming that the knock sensor is being used as a substitute value.)

I then replaced the crankshaft sensor with a new one (Bosch).
Conclusion: The same error as before.

After that, I measured the sensor's power supply voltage. There are 5V coming from the control unit to the sensor.
The mass (ground) is also connected by the control unit and therefore present.
I then examined the signal from the crankshaft position sensor using an oscilloscope. The signal is approximately 1 volt and fluctuates around 0.2 volts, but it's not a verschandeln or proper signal.



My current suspicion is that the donor wheel, which is mounted on the crankshaft (in the sealing flange), is defective.



I now have two questions.
"I seem to recall that there's a technical bulletin from Volkswagen regarding some PD TDI models, which specifies how to modify the shielding or grounding. Does this apply to this vehicle as well?"
Has anyone ever experienced a similar issue where the crankshaft sensor's toothed wheel was definitely defective?

I would like to rule out everything else beforehand before I remove the transmission and dual-mass flywheel and replace this sensor wheel. (It's not a quick job.)

Attached is a log from the start attempt until it starts up.

I can attach a car scan report if you would like.

Thank you very much for the answers.

Good morning, I found the error and just wanted to briefly report what caused it.

I measured the G28 sensor on a Caddy with an identical engine to determine what the target values are for the G28.

I measured a voltage of 5V on a cable (purple wire, pin 2) connected to the defective Touran, and I thought that was the supply voltage for the G28. Therefore, I assumed that pin 3 (wire color br/bl) was the switched ground, and pin 1 (sw/ro) was the signal line.
Unfortunately, that's not the case, as I discovered with the current Caddy.

The occupancy of room G28 is as follows:
Pin 1 sw/ro: 5V (continuous), powered by the control unit.
Pin 2 (li): Signal line; however, it also receives 5V when the ignition is turned on, but this voltage is...
Start engine / Run engine on signal from sensor G28.
Pin 3: Switched ground.

The problem was ultimately that the 5V power supply voltage wasn't reaching pin 1. The cause is either a broken cable from the control unit to the sensor, or the control unit is no longer supplying the 5V.
I temporarily took the 5V from the NOx sensor (the wires are located next to each other near the oil filter housing) and connected it to pin 1 of the G28.
Conclusion: The vehicle started immediately, and the error message disappeared.

Here is a section of the circuit diagram.

Thank you very much and have a nice weekend.

Excellent resolution .

The wiring diagrams at VAG (Volkswagen Group) leave much to be desired. They could indicate on the connectors where the 5V, ground, and signal lines are located. They should take a leaf out of BMW's book.

Hans Dampf wrote:

The cause is either a broken cable from the control unit to the sensor, or the control unit no longer outputs the 5V.

Could it not also be due to the following?

16706 - Motor speed sensor (G28).
P0322 - 000 - No signal - Warning light ON.
Environmental conditions:
Speed: 0 RPM.
Torque: 78.0 Nm
Speed: 0.0 km/h
Last: 0.0%
Voltage: 9.65 V
Binary value: 00001100
Idle stabilization: 0.0° KW.
Speed: 84 revolutions per minute.

The starting speed of 84 RPM was also quite low...

Hi Roger, no, that wasn't the cause. I only checked the error memory to post it on the forum (I hadn't saved it before). However, that was the morning after I had been measuring for a long time in the evening (with the ignition on) and made several starting attempts. I realized that later. But it has nothing to do with the problem. During the measurements, I always saw a better battery voltage.

Best regards...