Volkswagen Workshop Service and Repair Manuals

• ‒ 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 01 for display group 01 and confirm with Q.

Note:

If something different is indicated on the display:

Fault reader operating instructions

• ‒ Check idling switch at idling stop in display zone 4.

4th position from left must display 0
     Display: 00000000

• ‒ Slowly open throttle valve.

4th position from left must display 1
     Display: 00010000

• ‒ Switch off ignition

If the specifications are not attained:

• ‒ → Connect test box V.A.G 1598/18 to control unit wiring loom.
• ‒ With throttle valve closed connect multimeter to measure resistance at test box sockets 10+17.
       Specifications: max. 1.5 ω
• ‒ Slowly open throttle valve.
       Specifications: ∞ ω

If the specifications are not attained:

• ‒ → Separate 8 pin connector to throttle valve control part.
• ‒ Check wiring between test box and 8 pin connector for open circuit according to current flow diagram.
       Contact 3 + socket 10
       Contact 7 + socket 17
  Wire resistance: max. 1.5 ω
• ‒ Check wiring at 8 pin connector for short to one another.
  Contact 7 + socket 10
       Specification: ∞ω

If no wiring fault is detected:

• ‒ Replace throttle valve control part (J338).