Volkswagen Golf Mk1 Workshop Service Manuals & Auto Repair Guides

Test conditions

• ● Coolant temperature at least 80°C

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

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

• ‒ Input 03 for display group 03 and confirm with Q.

Note:

If something different is indicated on the display:

=> Fault reader operating instructions

• ‒ Check throttle valve positioner voltage at idling stop in display zone 4.
       Specification: 3.9...4.3V

If the specification is not attained:

• ‒ → Connect test box V.A.G 1598/18 to control unit wiring loom.
• ‒ With throttle value closed connect multimeter to measure resitance at test box socket 1+2.
       Specification:3...200 ω

If the specification is 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 1 + socket 2
       Contact 2 + socket 26
       Contact 7 + socket 17
       Contact 8 + socket 16
       Wire resistance: max. 1.5 ω

• ‒ → Check wiring at 8 pin connector for short to one another.
       Contact 1 + socket 26
       Contact 1 + socket 16
       Contact 1 + socket 17
       Contact 2 + socket 16
       Contact 2 + socket 17
       Contact 7 + socket 16
       Specification: ∞ ω

If no wiring fault is detected:

• ‒ Replace throttle valve control part (J338).