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

• ● → Fuse No. 14 must be OK.
• ● The battery voltage must be at least 11.5 V.
• ● Fuel pump relay must be OK

Test sequence

• ‒ 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 .)

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

• ‒ Press keys 0, 4 and 1 for "Display group number 41" and confirm entry with Q key.

• ‒ Run engine for 2 minutes at idling speed.
• ‒ Check Lambda probe heater status in display zone 4:
      Display: Htg.aC.ON, Htg.aC.OFF (alternating)

If the display does not indicate as described:

• ‒ Press ⇒key.
• ‒ Press keys 0 and 6 for the "End data transfer" function and confirm input with the Q key.
• ‒ Switch off ignition.

• ‒ → Separate 4-pin connector -2- to Lambda probe after catalyst (G130).

• ‒ → Set multimeter to check resistance and connect it to contacts 1 + 2 of Lambda probe connector. Check probe heating for continuity.
      Specification: 8...20 ω

If it is determined that probe heating has an open circuit:

• ‒ Renew the Lambda probe after catalyst (G130).
• ‒ Erase fault memory to put learnt values in a neutral setting => Page 01-18, Interrogating and erasing learnt values.

If probe heating has continuity:

• ‒ → Set multimeter to measure voltage and connect to contact 1 (connector to engine control unit) and earth.
• ‒ Start engine and run at idling speed.
• ‒ Check voltage supply:
      Specification: 11.0...14.5 V

If no voltage is present:

• ‒ Check wiring from contact 1 to fuel pump relay (J17) according to current flow diagram.

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

If the specification is obtained:

• ‒ → Connect multimeter to contacts 1 and 2 (connector to engine control unit).
• ‒ Measure the voltage supply:
  When display group 41, display zone 4 displays
  Display, Htg.aC.ON:
      Specification: 11.0...14.5 V
  Display, Htg. aC.ON/Htg.aC.OFF (alternating)
      Specification: Between 0.0...12.0 V fluctuating

If the specification is not obtained:

• ‒ Switch off ignition.
• ‒ Remove battery.

• ‒ → Connect test box V.A.G 1598/31 to control unit wiring harness. The engine control unit remains disconnected.

• ‒ → Check wiring between test box and 4-pin connector for open circuit using current flow diagram.
      Contact 2 and socket 63
      Wire resistance: Max. 1.5 ω

If no wiring fault is detected:

• ‒ Renew engine control unit => Page 24-109.