Passat 2.0 TDI - High pressure is below specification

Passat 2.0 TDI 110 hp.
0603 AOJ
Year of construction: 2009.
Approximately 400,000 km.
DPF, EGR, and turbocharger are still original.

The Passat wouldn't start.
The pressure reading on the Rail was only 50 bar (LOG-01-015).
After removing the control valve, metal shavings were visible inside the high-pressure pump.
I replaced the diesel filter, cleaned the high-pressure lines and the fuel rail, and then took the Passat to my workshop. I had the high-pressure pump and the timing belt replaced there.
After the replacement, the Passat is working again, but it shows discrepancies between the actual and target high-pressure values, and there is a quantity deviation in cylinder 1.
After replacing the injector for cylinder 1, there was no improvement.

The theory that the DPF was the cause didn't help me either. The regeneration process could not be started, and an hour of driving at high RPM did not improve the situation (LOG-01-011).

Does anyone have any suggestions as to the cause?

Best regards,
Lorenz

Was the tank and everything associated with it also cleaned?

Hello Rudi,
I only cleaned the high-pressure area.
Cleaning everything else would be a very significant effort. I rely on the diesel filter, which prevents metal shavings from passing through before they reach the high-pressure pump. Furthermore, my Passat is very old.

Best regards,
Lorenz

That was a big mistake.

Hello,
Can someone help me? What does it mean?

- Calibrate control valve (Error: "Block117 not available") (Image)

-How do I determine the learning values for the control valve (image)?

Best regards,
Lorenz

Hi,
Basically, everything downstream of the worn high-pressure pump, all the way to the diesel filter, is contaminated. This includes everything connected to the fuel rail, but also the pump in the tank. Without cleaning, you'll just end up with more problems.
It would be a stroke of luck if the injectors survived. If the rail pressure is too low, the problem can only be due to the pressure regulation system itself or the components involved (injectors, pre-injection pressure).
After cleaning, it would be advisable to perform an Autoscan first, so that the malfunction and its relationship to the environmental conditions become visible.
When performing fuel rail pressure measurements, this involves controlling the fuel metering valve and the fuel pressure regulating valve. Naturally, the speed and injection volume are adjustable.
When measuring the individual cylinder correction values for the engine management system, these include the average injection quantity, the engine speed, and the shift time corrections for each injector.
hg
Herbert.
Please provide the text you would like me to translate from German to English.

Hello,
Today, I discovered that the exhaust temperature sensor at the inlet of the DPF has a high resistance (>20 MOhms).
Could it be the cause?
-that the control valve cannot be calibrated?
-that the regeneration process cannot be started while the system is running?

Best regards,
Lorenz

Hello,
I need to correct myself.
The exhaust temperature sensor at the DPF inlet has a resistance of approximately 6.7 megaohms at 10°C.
Is this value okay for the sensor?

Best regards,
Lorenz

Hi,
Counter-question: Does the sensor also show 10° when the engine is cold and the outside temperature is 10°?
The real problem, however, is the rail pressure, which has very little to do with the DPF.
hg
Herbert.

Hello,
During my troubleshooting process, I warmed up the engine and obtained the following results (see image 2202). The instructions are a little confusing, but you can figure it out.

However, I'm stuck trying to figure out the reason why the control valve cannot be put into service. Data block 117 is not visible in my measurements (see image 2180 and image 2153).

Best regards,
Lorenz

Do you always have conversations with yourself and ignore all other people?

Hello Rainer,
I have taken your criticism to heart. I'm still affected by the issue my daughter had with her Alhambra, where the problem was only resolved by completely replacing the rail, high-pressure sensor, and control valve.

I have now taken the measurements (as suggested by Herbert). I couldn't find the "switching time correction" parameter in my Passat. For that, I used the mean deviation for the cylinders.
For cylinder 1, which showed the largest discrepancy in fuel quantity, I installed a new replacement injector about 14 days ago, but the result remains the same.
Meanwhile, I ordered some end caps for the rails so I can disconnect the cylinders. Unfortunately, the order ended up being shipped from China, and I'm still waiting for delivery.

Best regards,
Lorenz

Hello,
The caps have arrived. I was unable to locate the faulty injectors using that method.
I purchased and installed three more replacement injectors. The Passat is working again now.

Best regards,
Lorenz

Supplementary information: When checking the temperature sensor on the DPF, simply verify whether the temperature displayed in the engine control unit is reasonable.

The temperature sensor should not have a high impedance, as this could potentially cause a measurement error.

117: The measurement channels are the same, but the IDE often doesn't support advanced measurement features. Both come directly from the ECU, which determines what is available.