Volkswagen Workshop Service and Repair Manuals

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

1. Throttle valve positioner (V60)

2. Activated charcoal filter solenoid valve 1 (N80)

3. Exhaust gas recirculation valve (N18)
     (only engine code AHW)

4. Engine speed signal1)

5. Fuel pump relay (J17)

6. Engine/air conditioner compressor electrical connection

     1)     not relevant

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3A
• ◆ Test box V.A.G 1598/22
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Diode test lamp V.A.G 1527
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Check conditions

• ● → The fuses No. 27, 28, 30, 31, 32, 37 and 39 must be OK.
• ● The battery voltage must be at least 11.5 V.
• ● All electrical consumers, e.g. lights and rear window heating must be switched off.
• ● Throttle valve potentiometer (G69) OK.

Test requirements for vehicles with air conditioning system

• ● Vehicle at room temperature (warmer than + 15 °C)
• ● Air conditioning system switched on
• ● Select lowest temperature and highest blower speed

Notes:

• ◆ The final control diagnosis can only be carried out if the engine is stationary and ignition switched on.
• ◆ The final control diagnosis will be aborted if the engine is started or a rotational impulse is recognised.
• ◆ During the final control diagnosis the individual final controls will be activated until advancing to the next final control by pressing the ⇒ button.
• ◆ The final controls are checked acoustically or by touching.

Work sequence

• ‒ Connect the fault reader V.A.G 1551 (V.A.G 1552). Then switch ignition on and select engine control unit with the "Address word" 01.
  (Connecting fault reader and selecting engine control unit .)

• ‒ Operate fault reader taking into account the information on the display:
• ‒ Press keys 0 and 3 for the function "Final control diagnosis".

Activating throttle valve positioner (V60):

• ‒ Confirm input with Q key.

• The throttle valve positioner must open and close the throttle valve until switching to the next final control by pressing the ⇒key.

If the throttle valve positioner does not move:

• ‒ Check throttle valve positioner
  , checking throttle valve control part.

Activating activated charcoal filter solenoid valve 1 (N80):

• ‒ Press ⇒key.

• The solenoid valve (right-hand suspension turret) must click, until activating the next final control element by pressing ⇒key.

• ‒ Pull hose off activated charcoal filter at solenoid valve.
• ‒ Connect an auxiliary hose to the vacant valve connection.
• ‒ Blow into auxiliary hose during final control diagnosis (in direction of throttle valve control part).
       Valve must open and close

If the solenoid valve does not click:

• ‒ Continue check => Page 01-64 .

Activating exhaust gas recirculation valve (N18):

(only engine code AHW)

• ‒ Press ⇒key.

• The exhaust gas recirculation valve (engine compartment, left, on cylinder head) must click until the next final control is activated by pressing the ⇒key.

If the solenoid valve does not click:

• ‒ Continue check => Page 01-66 .

Continuation for all engines

Activating fuel pump relay (J17):

• ‒ Press ⇒key twice.

• The fuel pump relay (on the relay plate) must click until the next final control is activated by pressing the ⇒key.

Note:

During the activation of the fuel pump relay the fuel pump must be heard to run at intervals.

If the relay does not click:

• ‒ Check fuel pump relay:

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

Checking electric wiring to air conditioner:

Note:

The test step is only for vehicles with air conditioner. On vehicles without air conditioner end final control diagnosis by pressing ⇒key.

• The air conditioner compressor magnetic coupling must click, until ending final control diagnosis by pressing ⇒key.

If the magnetic coupling does not click:

• ‒ Check wiring from / to air conditioner
  

If the magnetic coupling clicks:

• ‒ Press ⇒key.

• ‒ Press keys 0 and 6 for the "End output" function and confirm input with the Q key.

• ‒ Switch off ignition.

Continuation of check when the activated charcoal filter solenoid 1 does not click:

• ‒ → Pull the 2 pin connector off solenoid valve 1 (N80) -arrow-.

• ‒ → Connect diode test lamp V.A.G 1527 using adapter cables from V.A.G 1594 to detached connector.
       The LED must flash (bright/darker)

LED flashes:

• ‒ Proceed with final control diagnosis until completed.
• ‒ Switch off ignition.
• ‒ Replace solenoid valve 1 (N80):

=> Repair group 20; Activated charcoal filter system; Removing and installing parts of activated charcoal filter system

LED does not flash:

• ‒ Proceed with final control diagnosis until completed.
• ‒ Switch off ignition.
• ‒ → Connect test box V.A.G 1598/22 to control unit wiring harness.

• ‒ → Check wire for open circuit between test box sockets 15 and 2 pin connector contact 2 using current flow diagram.
       Wire resistance: max. 1.5 ω
• ‒ Additionally check wire for short to battery positive and earth.
       Specification: ∞ω
• ‒ Check wire between 2 pin connector contact 1 and the fuel pump relay (J17) for open circuit using current flow diagram.
       Wire resistance: max. 1.5 ω

If no wiring fault is detected:

• ‒ Replace engine control unit
  => Page 24-106 .

Continuation of check when the exhaust gas recirculation valve does not click:

• ‒ → Pull the 2 pin connector off exhaust gas recirculation valve (N18) -arrow- (on camshaft housing, left).

• ‒ → Connect the diode test lamp V.A.G 1527 using adapter cables from V.A.G 1594 to detached connector.
       The LED must flash (bright/darker)

LED flashes:

• ‒ Proceed with final control diagnosis until completed.
• ‒ Switch off ignition.
• ‒ Replace the exhaust gas recirculation valve (N18):

=> Repair group 26; Exhaust gas recirculation system; Servicing parts of the exhaust gas recirculation system

LED does not flash:

• ‒ Proceed with final control diagnosis until completed.
• ‒ Switch off ignition.
• ‒ → Connect test box V.A.G 1598/22 to control unit wiring harness.

• ‒ → Check wire for open circuit between test box socket 72 and 2 pin connector contact 2using current flow diagram.
       Wire resistance: max. 1.5 ω
• ‒ Additionally check wire for short to battery positive and earth.
       Specification: ∞ω
• ‒ Check wire between 2 pin connector contact 1 and the fuel pump relay (J17) for open circuit using current flow diagram.
       Wire resistance: max. 1.5 ω

If no wiring fault is detected:

• ‒ Replace engine control unit
  => Page 24-106 .