The test is used to check the air valve's function.
"AdBlue air pressure in supply module" must drop below 550 mbar within 30 seconds.
Test procedure if above is not reached:
* Check return line.
* Replace the air valve in the supply module.
Test conditions:
Ignition on, engine off.
Procedure:
Start the function.
Follow the instructions in the program.
The function is done.
If the function fails, check the test conditions and repair any faults.