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Volkswagen Workshop Service and Repair Manuals

Motronic injection and ignition system > < Checking knock sensor
Simos injection and ignition system
Servicing ignition system
Check misfiring recognition

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 1551/3

Test sequence

  • ‒ Connect fault reader V.A.G 1551 (V.A.G 1552). Start engine and select "Address word" 01 of engine control unit. When doing this the engine must be running at idling speed.
    (Connecting fault reader and selecting engine control unit .)
 
→ Indicated on display:
Rapid data transfer     HELP
Select function XXX
  • ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.
 
→ Indicated on display:
Read measured value block
Input display group number XXX
  • ‒ Press keys 0, 1 and 4 for "Display group number 14" and confirm entry with Q key.
 
→ Indicated on display:
(1...4 = Display zones)
Read measured value block 14     ⇒
     1     2     3     4
  • ‒ Check misfire recognition status in display zone 4.
         Specification: "activated"
  • ‒ Check total number of misfires since engine was started in display zone 3:
         Specification: 0...20

Note:

The specification is only valid for a period of max. 5 minutes after the engine was started.

If the specifications are obtained:

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

If the specifications are not attained:

  • ‒ Change to display group 15 as follows:
         V.A.G 1551: Press key 3
         V.A.G 1552: Press key ↑
 
→ Indicated on display:
(1...4 = Display zones)
Read measured value block 15     ⇒
     1     2     3     4
  • ‒ Check misfire recognition status in display zone 4.
         Specification: "activated"
  • ‒ Check misfiring of cyl. 1...cyl. 3 since engine was started in display zones 1...3.
         Specification: 0...5

Note:

The specification is only valid for a period of max. 5 minutes after the engine was started.

If the specifications are not obtained:

  • ‒ Press ⇒key.
  • ‒ Press keys 0 and 6 for the "End output" function and confirm input with the Q key.
  • ‒ Switch off ignition.
  • ‒  , Evaluating display group 15 and display group 16.

If the specifications are obtained:

  • ‒ Change to display group 16 as follows:
         V.A.G 1551: Press key 3
         V.A.G 1552: Press key ↑
 
→ Indicated on display:
(1...4 = Display zones)
Read measured value block 16     ⇒
     1     2     3     4
  • ‒ Check misfire recognition status in display zone 4.
         Specification: "activated"
  • ‒ Check misfiring of cyl. 4 since engine was started in display zone 1
         Specification: 0...5
  • ‒ Press ⇒key.
  • ‒ Press keys 0 and 6 for the "End output" function and confirm input with the Q key.
  • ‒ Switch off ignition.

If the specification is not attained:

  • ‒  , Evaluating display group 15 and display group 16.

Motronic injection and ignition system > < Checking knock sensor