SEAT Workshop Service and Repair Manuals

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 box V.A.G 1598/31
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Check conditions

• ● → All fuses must be OK.
• ● The battery voltage must be at least 11.5 V.
• ● Speedometer must be OK., checking speedometer:

=> Electrical system; Repair group 90

Test sequence

Note:

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

Observe the valid safety precautions when carrying out a road test .

• ‒ 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 => Page 01-9.)

• ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

• ‒ Press keys 0, 0 and 5 for "Display group number 5" and confirm entry with Q key.

• ‒ Carry out test drive with a 2nd person to observe display.

Observe the valid safety precautions when carrying out a road test => Page 24-32.

• ‒ Observe figure displayed in display zone 3:
      Specification: approx. driven speed
• ‒ => Page 01-123, display group 5 and evaluation
• ‒ Press the ⇒key.
• ‒ Press keys 0 and 6 for the "End output" function and confirm input with the Q key.
• ‒ Switch off ignition.

If no speed is displayed:

• ‒ → Connect test box V.A.G 1598/31 to control unit wiring harness. The engine control unit remains disconnected.
• ‒ Connect multimeter to measure voltage between test box sockets 2+54.
• ‒ Switch on ignition.
• ‒ Lift vehicle at front left.
• ‒ Rotate front wheel and observe voltage display.
      Specification: between 0 and at least 4 Volt fluctuating

Note:

If necessary, hold the front right wheel to prevent it from turning.

If the display does not fluctuate:

• ‒ Check wiring from combi-instrument to vehicle speed sender or to automatic gearbox control unit.

=> Current flow diagrams, Electrical fault finding and Fitting locations

• ‒ Interrogate fault memory, if necessary, repair any faults and then erase fault memory => Page 01-16, interrogating and erasing fault memory.
• ‒ Read-out the readiness code=> Page 01-64.