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

• ● Coolant temperature must be at least 80 °C, =>display group 04, display zone 3.
• ● All electrical consumers, e.g. lights and rear window heating must be switched off
• ● If the vehicle is equipped with an air conditioning system, this must be switched off.
• ● On vehicles with automatic gearbox selector lever in "P" or "N" position

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, 0 and 2 for "Display group number 2" and confirm entry with Q key.

• ‒ Check the air mass drawn in in display zone 4
      Specification: 1.0...5.0 g/s

If the specification is obtained but there is a fault regarding air mass meter registered in the fault memory:

• ‒ Check the voltage supply for the air mass meter => Page 24-35.

If the specification is not obtained:

• ‒ Check the signal and earth wires for the air mass meter => Page 24-36.

If the specification is obtained:

• ‒ Press the ⇒key.

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

Checking voltage supply for air mass meter

• ‒ → Pull 5 pin connector -1- off air mass meter -2-.

• ‒ → Connect multimeter to measure voltage on connector contact 2 and engine earth.
• ‒ Start engine and run at idling speed.

•     Specification: 11...15 V

If no voltage is present:

• ‒ Switch off ignition.
• ‒ Check wiring from contact 2 to fuel pump relay (J17) according to current flow diagram.

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

If the voltage supply and wiring is OK:

• ‒ Switch ignition on.
• ‒ Connect multimeter to measure voltage on connector contact 4 and engine earth:
      Specification: 4.5...5.5 V

If no voltage is present:

• ‒ Switch off ignition.

• ‒ Check the signal and earth wires => Page 24-36.

Testing signal and earth wires for air mass meter

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

• ‒ → Check wiring for open circuit between test box and 5-pin connector using current flow diagram.
      Contact 5+socket 29
      Contact 4+socket 53
      Contact 3+socket 27
      Wire resistance: Max. 1.5 ω
• ‒ Additionally check wires for short to one another.
• ‒ Additionally check the wiring for short to battery positive or earth.

Note:

When servicing connectors only gold-plated contacts are to be used.

If no wiring fault is detected:

• ‒ Renew air mass meter (G70) , item 3.