SEAT Workshop Service and Repair Manuals

Special tools, 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 1598/18
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Test sequence

• ‒ Connect fault reader V.A.G 1551 (V.A.G 1552) and select engine electronics control unit with the "Address word" 01. When doing this the engine must be running at idling speed.
  (Connecting fault reader and selecting engine electronics 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 7 for "Display group number 7" and confirm entry with Q key.

If faulty the following substitute values will be displayed:
    Engine codes AHU, 1Z: 18.9°C
    Engine codes AFN, AVG: 136.8°C

• ‒ If no realistic value is displayed in display zone 3 or the substitute is displayed. Check intake manifold temperature sender and wiring to sender as follows:
• ‒ Press the ⇒key.
• ‒ Press keys 0 and 6 for the "End data transfer" function and confirm input with the Q key.

• ‒ Switch off ignition.
• ‒ → Pull connector -1- off intake manifold temperature sender -2-.
• ‒ Measure resistance between sender contacts.

• → Specification see diagram

Scale A shows resistance values for temperature range 0...50 °C and scale B the values for temperature range 50...100 °C.

Examples:

• ◆ 30 °C corresponds to a resistance from 1500...2000 ω
• ◆ 80 °C corresponds to a resistance from 275...375 ω

If the specification is not obtained:

• ‒ Replace intake manifold temperature sender (G72).

If the specification is obtained:

• ‒ Remove dash panel insert:

=> Electrical system; Repair group 90; dash panel insert; removing and installing dash panel insert

• ‒ → Connect test box V.A.G 1598/18 to control unit wiring loom.

• ‒ → Check wiring between test box and connector for open circuit according to current flow diagram.
      Contact 1+ socket 64
      Contact 2+ socket 33
      Wire resistance: max. 1.5 ω
• ‒ Additionally check wires for short to one another, to vehicle earth and to battery positive.
      Specification: ∞ω

If no wiring fault is detected:

• ‒ Renew Diesel direct injection system control unit (J248) => Page 23-5, item 9.