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Basic setting > < Fault codes up to fault code P1854 (18262)

A4 Mk1

Motronic Fuel Injection and Ignition System (6-cyl. Turbo)
Final control diagnosis
Final control diagnosis

Notes:

  • ◆ The final control diagnosis can only be performed with the engine stopped and the ignition switched on.
  • ◆ The final control diagnosis is terminated if the engine is started or if an engine speed pulse is detected.
  • ◆ During final control diagnosis, the individual control elements are operated in turn for about one minute (except injectors) unless the next control element is selected by pressing the ⇒ key.
  • ◆ The control elements can be checked acoustically or by way of touch.
  • ◆ Engine must be started before repeating the final control diagnosis. (Engine control unit has to have recognised a speed greater than 300 rpm.)
  • ◆ The electric fuel pump runs throughout the final control diagnosis.

The final control diagnosis activates the following components in the stated order:

Actuation sequence

1

Solenoid valve 1 for activated charcoal filter -N80
(Tank breather valve -N80)

2

Boost pressure limitation solenoid valve -N75

3

Camshaft timing control

4

Air recirculation valve for turbocharger -N249

5

Injector, cylinder 1 -N30

6

Injector, cylinder 4 -N33

7

Injector, cylinder 3 -N32

8

Injector, cylinder 6 -N84

9

Injector, cylinder 2 -N31

10

Injector, cylinder 5 -N83

Test conditions

  • ● Fuses for engine electronics OK
  • ● Fuel pump relay OK.
  • ‒ Connect the vehicle diagnostic, testing and information system VAS 5051 or fault reader V.A.G 1551 and select the engine electronics control unit with "address word" 01 .
    For this purpose, the ignition must be switched on.
 
→ Indicated on display:
Rapid data transfer     HELP
Select function XX
  • ‒ Press keys 0 and 3 for "Final control diagnosis" function
 
→ Indicated on display:
Rapid data transfer    Q
03 - Final control diagnosis

Actuation of activated charcoal filter system solenoid valve (tank breather valve)

  • ‒ Confirm input with Q key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Tank breather valve -N80

This solenoid valve is actuated (clicks) for approx. one minute unless the ⇒ key is pressed to switch to the next control element.

If the valve is not actuated (does not click).

  • ‒ Check solenoid valve 1 for activated charcoal filter -N80 => Page 24-137.

Activating solenoid valve for boost pressure limitation -N75

  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Solenoid valve for boost pressure limitation
-N75

This solenoid valve is actuated (clicks) for approx. one minute unless the ⇒ key is pressed to switch to the next control element.

If the solenoid valve for boost pressure limitation does not click:

=> Mechanical Components; Repair group 21; Charge air system with turbocharger; Checking boost pressure limitation solenoid valve -N75.

Actuation of camshaft adjustment valves

  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Camshaft adjustment 1
  • ‒ Valves 1 and 2 for camshaft adjustment are actuated (click) for approx. one minute unless the ⇒key is pressed to switch to the next control element.

If the valve is not actuated (does not click).

=> Mechanical Components; Repair group 15; Checking camshaft adjustment; Checking camshaft adjustment solenoid valves

Actuating air recirculation valve for turbocharger

  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Air recirculation valve for turbocharger -N249

This solenoid valve is actuated (clicks) for approx. one minute unless the ⇒ key is pressed to switch to the next control element.

If the valve is not actuated (does not click).

=> Mechanical Components; Repair group 21; Charge air system with turbocharger; Testing air recirculation valve for turbocharger -N249

Actuating injectors

Note:

The injectors are activated according to the firing sequence, i.e. cyl. 1, cyl. 4, cyl. 3, cyl 6, cyl. 2, cyl 5.

  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 1 -N30
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 1 -N30

After the arrow key is pressed, the injector must click five times.

If the injector does not click:

  • ‒ Test injectors => Page 24-46.
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 4 -N33
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 4 -N33

After the arrow key is pressed, the injector must click five times.

If the injector does not click:

  • ‒ Test injectors => Page 24-46.
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 3 -N32
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 3 -N32

After the arrow key is pressed, the injector must click five times.

If the injector does not click:

  • ‒ Test injectors => Page 24-46.
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 6 -N84
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 6 -N84

After the arrow key is pressed, the injector must click five times.

If the injector does not click:

  • ‒ Test injectors => Page 24-46.
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 2 -N31
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 2 -N31

After the arrow key is pressed, the injector must click five times.

If the injector does not click:

  • ‒ Test injectors => Page 24-46.
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 5 -N83
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Injector, cylinder 5 -N83

After the arrow key is pressed, the injector must click five times.

If the injector does not click:

  • ‒ Test injectors => Page 24-46.
  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
END
  • ‒ Press the ⇒key.
 
→ Indicated on display (function selection):
Rapid data transfer     HELP
Select function XX

Important note:

The final control diagnosis can only then be started again after the engine has started and the ignition has been switched off and on again.

Basic setting > < Fault codes up to fault code P1854 (18262)