Volkswagen Workshop Service and Repair Manuals

Check for Digifant 3.2 only (10.94▸)

(Interrogate control unit version ; Connecting fault reader V.A.G 1551 and selecting engine electronics control unit).

Note:

Check establishes whether Digifant control unit (J169) recognises the engine operating modes (idling, part throttle, full throttle, overrun).

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

• ● Coolant temperature at least 80 °C

Test sequence

• ‒ Connect fault reader V.A.G 1551 (V.A.G 1552) and select engine electronics control unit with the "Address word" 01. When doing this the engine must be running at idling speed.
  (Connecting fault reader and selecting engine electronics control unit => Page 01-4 .)

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

• ‒ Enter 04 for "Display group number" and confirm with Q key.

• ‒ Observe display zone 4 -8 digit number block-:
  (The right-hand 4 digits are of no consequence)

Display in operating mode

• ◆ Idling:

• 2nd position from left must display 1
       Display: 01000000

• ◆ Part throttle:

• ‒ Rev up evenly.

• 3rd position from left must display 1
       Display:: 00100000

• ◆ Full throttle:

• ‒ Floor accelerator pedal and release.

• 4th position from left must briefly display 1
       Display: 00010000

• ◆ Overrun mode:

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

• As long as the engine speed is above 1500 rpm 1st position from left must display 1
       Display: 11000000 (briefly)

Note:

Below 1500 rpm idling speed is again recognised.

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

If the specifications are not attained:

• ‒ Interrogate fault memory, if necessary, repair fault and erase fault memory.
  => Page 01-7 , interrogating and erasing fault memory
• ‒ Check throttle valve potentiometer
  => Page 24-43 .
• ‒ Check idling switch => Page 24-62 .