Volkswagen Workshop Service and Repair Manuals

Notes:

• ◆ Idling speed, ignition timing and CO content not adjustable.
• ◆ The idling speed is regulated to specification by the throttle valve positioner in conjunction with the DIS function.
• ◆ The position of the distributor has no influence on ignition timing.

• ◆ CO content regulated by Lambda control. Faults in Lambda control are detected in self-diagnosis and stored in fault memory.

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

Check conditions

• ● Engine oil temperature at least 80 °C
• ● Electrical consumers switched off (radiator fan must not run during the check)
• ● Air conditioner switched off
• ● Accelerator cable adjustment OK

=> Repair group 20, removing and installing parts of the fuel supply system, adjusting accelerator cable

Test sequence

• ‒ Start engine and run at idling speed.
• ‒ Interrogate fault memory, if necessary, repair fault and erase fault memory.
  , interrogating and erasing fault memory

• ‒ Then:
• ‒ Leave fault reader V.A.G 1551 connected.
• ‒ Continue running engine at idling speed.

• ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

• ‒ Press keys 0 and 1 for "Display group number 01" and confirm entry with Q key.

Do not continue with check until a 1 appears in display zone 4 - 8 digit number block - 00000010.

Note:

If at one or more positions a 1 is displayed in display zone 4, the test conditions have not been fulfilled:

; Relevance of figures in 8 digit number block

• ‒ Allow engine to idle for at least 1 minute.
• ‒ Check idling speed in display zone 1.
       Specification ADY, AGG: 750...850 rpm1)
       Specification AFT: 790...890 rpm1)

     1)     Up-to-date specifications:

=> Emissions test binder

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

If the specification is not obtained:

• ‒ Perform basic setting => Page 24-37
• ‒ Carry out road test, interrogate fault memory again and repeat idling check.

If the specifications are again not attained:

• ‒ Check throttle valve control part
  => Page 24-57 .