Volkswagen Workshop Service and Repair Manuals

Note:

Check establishes whether Motronic control unit (J220) recognises the engine operating condition.

Special tools, testers and auxiliary items

• ◆ Fault reader V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3

Test conditions

• ● Engine oil temperature min. 80 °C

Test sequence

• ‒ Connect fault reader V.A.G 1551 (V.A.G 1552) and select engine electronics control unit (address word 01); carry out selection at idling.
  

• ‒ Input 08 for "Read measured value block" function and confirm with Q.

• ‒ Input 04 for display group 04 and confirm with Q.

Note:

If something different is indicated on the display:

=> Fault reader operating instructions

Display for operating modes:

• ◆ Overrun mode:

• ‒ Increase engine speed to above 3000 rpm.
• ‒ Close throttle abruptly.

• As long as the engine speed is above 1500 rpm 5th position from left must display 1
       Display: 00001

Note:

Below 1500 rpm idling speed will be recognised.

• ◆ Idling:

• 4th position from left must display 1
       Display: 00010

• ◆ Part throttle:

• ‒ Rev up evenly.

• 3rd position from left must display 1
       Display:: 00100

• ◆ Full throttle:

• ‒ Floor accelerator pedal and release.

• 2nd position from left must briefly display 1
       Display: 01000

• ◆ Acceleration enrichment:

• ‒ Floor accelerator (rev-up to above 3000 rpm).

• 1st position from left must display 1
       Display: 10000

• ‒ Press ⇒ button.
• ‒ Input 06 for "End output" and confirm with Q.

If the specifications are not attained:

• ‒ Interrogate and erase fault memory, eliminate faults if necessary => Page 01-8 .
• ‒ Check accelerator mechanism for ease of operation.
• ‒ Check throttle valve potentiometer
  => Page 24-43 .