Engine Error: Red Light, No Stored Code

Hello, diesel mechanics.

Yesterday, I replaced the AGR module. After that, during the test drive, the dashboard displayed an engine fault (the engine oil symbol on the console was flashing red, indicating low engine oil pressure), but there was no error code registered when I scanned the error memory using the VCDS tool.
Of course, there is enough oil. I haven't found any open connectors. Opening the connector to the oil pan triggers an error message, so the VCDS tool is working. The red flashing light disappears when the engine is idling; it doesn't appear when the engine is started, but only when the vehicle is in motion.
Could the connector to the AGR module be the cause? Why isn't this triggering an error code?

Thank you for any advice,
Diesler.

I would start by checking the oil pressure and the oil pressure switch.

Best regards, Rainer.

Hello Rainer

Thank you for the helpful and clear information. . My additional question: Can the pressure test be performed using the VCDS tool? Is it sufficient for a beginner to simply read the user manual to find the appropriate measurement block? Or do I need additional documentation?

Best regards,
Jürgen.

Hi Diesla!

IMPORTANT
Do not move the vehicle until the oil pressure CHECK IS COMPLETED .

The oil pressure is - depending on the variant/software version - NOT MONITORED below 1,500/2,000 RPM.

At address 17 in the diagnostic module, the status of the oil pressure switch can be read, typically displaying "not in operation" or "in operation." No error code is stored in the error memory!

You can't take such a message lightly, especially when it comes from VAG!

...and before anyone asks a question about this: No, not everything can be checked or repaired remotely from a laptop!!!
Oil pressure testing can be done with a pressure gauge connected to the oil pressure switch, but it's better to have it done by a professional in a workshop.

Best regards from Munich!

Hello DieselBär30x ,

I will take your advice to heart and will not move the car anymore. I will measure the oil pressure as described in my manual. If that doesn't work, I will take it to the workshop.

Best regards,
Diesler.

Title: Engine fault (red flashing light) but no error code stored.
More specifically: The oil can symbol is flashing red in the console. Warning: Do not proceed! Engine oil pressure is too low.

Hello.

I received this error message after performing my own repair on my Golf VI 1.6 TDI CAYC. Also, I remember what my driving instructor said: "If the oil pressure light comes on, it's too late."
However, that was in the past; today, there's a chance... and you should pay attention to the tips provided by DieselBär30x on July 18, 2016, at 21:07. Information on how to check the oil pressure switch and the oil pressure can be found, among other places, in the documentation I used, "Golf VI," see above, page 80.
However, one could be even "luckier" and have unplugged the connector for the oil pressure switch and not plugged it back in.

Best regards,
Diesler.

Hi Diesla!

Well, that bear was lucky .
I would still give more credence to the saying your driving instructor used, especially now.
As I mentioned before, the oil pressure will "possibly" no longer be monitored below 1,500/2,000 RPM, and the second oil pressure switch, which was used before 1998 for the "true" dynamic oil pressure control, is no longer needed.

You can try again: disconnect the cable from the oil pressure sensor again, and then see how far you can get, essentially without any oil, while driving perfectly well in quiet city traffic .
It is then officially referred to as "state of the art."

By the way, I am firmly convinced that the well-known problem with the oil pump drive/hexagonal shaft/countershaft module, which often leads to a complete failure of the engine's oil supply, would have caused significantly fewer consequential damages if the oil pressure control had been properly implemented.
Hat viele erwischt und z. T. significantly!
Including, among others, the host here: https://community.dieselschrauber.org/en/viewtopic.php?t=28002

Even though the error in this specific case was a self-inflicted one related to the main topic, such a MIL (manufacturing incident report) should never be taken lightly!

Best regards from Munich!