Volkswagen Workshop Service and Repair Manuals

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

     1)     Ignore display

Special tools, testers and auxiliary items

• ◆ Fault reader V.A.G 1551 with cable V.A.G 1551/3
• ◆ Adapter set V.A.G 1594
• ◆ Diode test lamp V.A.G 1527

Test conditions

• ● Throttle valve potentiometer (G69) OK.

Work sequence

• ‒ Connect fault reader V.A.G 1551 and select engine electronics control unit (address word 01); carry out selection with ignition switched on.
  

• ‒ Operate fault reader taking into account the information on the display:
• ‒ Input 03 for "Final control diagnosis" function.

Note:

If something different is indicated on the display:

=> Fault reader operating instructions

Activate Cyl. 1 injector (N30):

• ‒ Confirm input with Q button.

• ‒ If something different is displayed, press ⇒ button repeatedly until "Select function XX" appears.
• ‒ Input 03 again for function "Final control diagnosis" and confirm with Q button.
• ‒ Open throttle valve fully and close again.
       The Cyl. 1 injector must click

Note:

All injectors click extremely quietly!

To activate injectors, Cyls. 2...4 in each case:

• ‒ Open throttle valve fully again and close.

Skipping individual tests:

• ‒ Press ⇒button.

If one or more injectors do not click:

• ‒ Continue final control diagnosis to the end.
• ‒ Switch off ignition.
• ‒ Checking injector actuation (resistance and current supply) => Page 24-49 , checking injectors.

Activate idling stabilization valve (N71):

• ‒ Press ⇒button.

• The idling stabilization valve must click, until switching to the next final control by pressing the ⇒button.

If the idling stabilization valve does not click:

• ‒ Switch off ignition.
• ‒ Pull connector off valve.
• ‒ Connect diode test lamp V.A.G 1527 with aux. cables from V.A.G 1594 to contacts 1 and 2 of detached connector.
• ‒ Switch on ignition.
• ‒ Repeat final control diagnosis -idling speed stabilization valve (N71)-.
       LED must flash

LED flashes:

• ‒ Renew idling stabilization valve.

LED does not flash:

• ‒ Switch off ignition.
• ‒ Reconnect connector to valve.
• ‒ Carry out electrical check => Page 01-40 , test step 26, renew Motronic control unit (J220) if necessary.

Activate solenoid valve 1 for activated charcoal filter (N80):

• ‒ Press ⇒button.

• The activated charcoal filter solenoid valve 1 (on air cleaner housing) must click until the next final control element is selected by pressing the ⇒ button.

• ‒ Pull hose off solenoid valve (from activated charcoal filter).
• ‒ Connect auxiliary hose.
• ‒ During final control diagnosis blow into auxiliary hose (in direction of throttle housing).
       Valve must open and close

If the solenoid valve does not click:

• ‒ → Pull 2 pin connector off valve and connect diode test lamp V.A.G 1527 with aux. cables from V.A.G 1594 to disconnected connector.
       The LED must flash

LED flashes:

• ‒ Renew solenoid valve.

LED does not flash:

• ‒ Switch off ignition.
• ‒ Reconnect connector to valve.
• ‒ Carry out electrical check
  => Page 01-40 , test step 17.
• ‒ Renew Motronic control unit (J220) if necessary.

Activate Lambda probe heating relay (J278):

• ‒ Press ⇒ button.

• The Lambda probe heating relay (on additional relay plate) must click until the next control element is activated by pressing the ⇒ button.

If the relay does not click:

• ‒ Switch off ignition.
• ‒ Carry out electrical check => Page 01-40 , test step 5 or locate short circuit according to current flow diagram and rectify:

=> Current flow diagrams, Electrical fault finding and Fitting locations binder

If an open circuit cannot be located:

• ‒ Renew Lambda probe heating relay (J278) or Motronic control unit (J220) as necessary.
• ‒ Press ⇒ button.

• ‒ Press ⇒ button.

• ‒ Press ⇒ button.

Note:

After completion of the final control diagnosis input 06 for "End output" function and confirm with Q.

• ‒ Switch off ignition.