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Basic setting > < Fault codes 17514 - 18020

A4 Mk1

MPI fuel injection and ignition system
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 the final control diagnosis, individual control elements continue to be actuated until the test programme is advanced to the next control element by pressing the ⇒ key.
  • ◆ The control elements can be checked either by listening or by touching.
  • ◆ If the final control diagnosis is to be repeated without first starting the engine briefly, switch off the ignition for approx. 20 seconds.

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

Activation sequence

1

Fuel pump relay -J17

2

Idling stabilisation valve -N71

3

Intake manifold changeover valve -N156

4

ACF solenoid 1 -N801)

5

EGR valve -N182)

    1)    Vehicles with lambda probes only

    2)    Vehicles with EGR only

Test requirements:

  • ● Fuses for engine OK
  • ● Idling switch -F60 OK
  • ● Fuel pump relay -J17 OK

Test sequence

  • ‒ Connect up vehicle diagnosis, measurement and information system VAS 5051 or fault reader V.A.G 1551 and select engine electronics control unit with "Address word" 01 .
    Engine must not be running.
 
→ Indicated on display:
Rapid data transfer    HELP
Select function XX
  • ‒ Enter "03" for the "Final control diagnosis" function and confirm entry with Q key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Fuel pump relay -J17
  • The relay must be energised and the fuel pump must run. Flow noise at fuel pressure regulator is clearly audible.

If the relay does not pull:

  • ‒ Check actuation of the fuel pump relay -J17 => Page 24-45.

Actuating idling stabilisation valve

  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Idling stabilisation valve -N71
  • The idling stabilisation valve must hum and vibrate.

Note:

The clicking of the valve is difficult to hear and is therefore best checked by touch.

If the valve does not hum and vibrate:

  • ‒ Check idling stabilisation valve -N71 => Page 24-49.

Actuating the intake manifold change-over valve

  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
Intake manifold changeover valve -N156
  • The valve must click.

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

  • ‒ Check intake manifold changeover valve -N156 => Page 24-62.

Actuating the ACF solenoid

  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
ACF solenoid 1 -N80
  • The valve must click.

If the valve does not click:

  • ‒ Check ACF solenoid 1 -N80 .

Actuating the EGR valve (vehicles with EGR only)

  • ‒ Press the ⇒key.
 
→ Indicated on display:
Final control diagnosis    ⇒
EGR valve -N18
  • The valve must click.

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

  • ‒ Check EGR valve => Page 24-105
  • ‒ Press the ⇒key.
 
→ Indicated on display (function selection):
Rapid data transfer     HELP
Select function XX

Note:

Before selecting function 03 "Final control diagnosis" again, switch off the ignition for approx. 20 seconds.

Basic setting > < Fault codes 17514 - 18020