The explanation comes from the error code reference in the AvtoElektrik PRO app.
Meaning for specific makes
The same number can mean different things for different makes. Below is the make-specific meaning.
Volkswagen, Audi, Skoda, Seat: AdBlue pressure too low (leak at the injector)
Don’t put off the repair
OA fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.
Possible causes
AdBlue leak at the line connector at the injector (connector weld defect)
White AdBlue crystals on the connector
What you can do yourself
Inspect the line connector at the injector in the engine compartment
If there are crystals — rinse the area with water, replace the supply line
Top up AdBlue; the injector usually doesn’t need replacing
Stop and don’t drive on if:
The Check Engine light is flashing
The temperature gauge is in the red or the overheating light is on
The red oil pressure light is on
Smoke from under the bonnet, a burning or petrol smell
Strong jerking, knocking from the engine, or the car barely moves
OOOleg’s tip: check the connector
Often the cause is simple — there is no contact in the connector (plug). Look at the connector from the back: remove the rubber seal and you will see whether a wire is corroded or has come off completely. Corrosion shows up as green deposits. Ideally, gently pull each wire towards you one at a time: a sound wire stays in place, while a corroded one simply comes off — it needs to be repaired.
Unplug and inspect connectors with the ignition off.
Couldn’t fix it yourself? Oleg, an auto electrician, does computer diagnostics and repairs: he comes out anywhere in Almaty or sees you at his workshop.
Oleg’s course “Car computer diagnostics with a scan tool”: how to hook up a scanner, read codes and live data, and use them to find the cause. The first lessons are free.
The reference is kept by Oleg Dmitriev, an auto electrician from Almaty with 26 years of experience: computer diagnostics of cars and trucks, repair of control units (ECUs). Can’t find the cause? Message him.