Volkswagen Workshop Service and Repair Manuals

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
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Test conditions

• ● Speedometer OK., checking:

=> Repair group 90, Electrical system

Note:

To check the speed signal the vehicle must be driven. To do this a second person is necessary.

Test sequence

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

Notes:

• ◆ If something different is indicated on display:

=> Fault reader operating instructions

• ◆ If an incorrect input causes "Fault in the data transfer!" to be indicated, disconnect cable from fault reader, then reconnect and repeat work steps.

• ‒ Carry out test drive and when doing this observe display (2nd person necessary).
• ‒ Observe displayed figure in display zone 3:
       Specification: approx. driven speed
• ‒ Press ⇒ key.
• ‒ Input 06 for "End output" and confirm with Q.

If no speed is indicated:

• ‒ → Detach 3 pin connector from sender -1-.
• ‒ Switch on ignition.

• ‒ → Check voltage between contacts 1+3 of detached connector.
       Specification: Min. 9 V
• ‒ Switch off ignition
• ‒ Reconnect connector

If no voltage was present:

• ‒ Check wiring according to current flow diagram.

If voltage was min. 9 V:

• ‒ → Connect test box V.A.G 1598/18 to control unit wiring loom.
• ‒ Check wiring between single connector behind the central electrics and socket 65 for open circuit according to current flow diagram.
       Wire resistance: Max. 1.5 ω
• ‒ Connect multimeter to measure voltage at sockets 56 + 65.
• ‒ Switch on ignition.
• ‒ Raise left front wheel or push vehicle. The voltage figure must fluctuate between
       0...at least 4 V.

If no wiring fault is detected and voltage was present between contacts 1+3:

• ‒ Replace speedometer sender (G22).