SEAT Workshop Service and Repair Manuals

Note:

The intake air temperature sender (G42) is a part of the air mass meter (G70) and cannot be renewed individually.

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
• ◆ Pliers V.A.G 1921 for spring type clips
• ◆ Chilling spray (commercially available)

Test sequence

Note:

Only gold-plated contacts must be used to repair the contacts in the intake air temperature sender.

• ‒ Connect the fault reader V.A.G 1551 (V.A.G 1552). Then switch ignition on and select engine control unit with the "Address word" 01.
  (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 4 for "Display group number 4" and confirm entry with Q key.

• ‒ Read off intake air temperature value in display zone 4.

1)    If a temperature is displayed which is less than the ambient temperature of the sender, check sender wiring for transfer resistances. When doing this be aware that when stationary the sender can be heated-up by radiated heat.

Evaluating display group 4, display zone 4 - Intake air temperature

Continuation of check when display = ambient temperature:

• ‒ Remove intake hose between air mass meter and throttle valve control part.
• ‒ Note intake air temperature value in display zone 4.

• ‒ → Spray sender -arrow- with commercial chilling agent whilst observing the temperature value. The temperature value must
      decrease.
• ‒ Press ⇒key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
• ‒ Switch off ignition.

Continuation of check when display reads approx. -40.0 °C:

• ‒ → Pull 5-pin connector off air mass meter (G70) with intake air temperature sender (G42) -arrow-.

• ‒ → Bridge connector contacts 1+3 using aux. cables from V.A.G 1594 and observe display.

If display jumps to approx. 140.0 °C:

• ‒ Press ⇒key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
• ‒ Switch off ignition.
• ‒ Renew air mass meter (G70).
• ‒ 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.

If display remains at approx. -40.0 °C:

• ‒ Press ⇒key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.

• ‒ Switch off ignition.
• ‒ Check wiring using current flow diagram
  => Page 24-83

Continuation of check when display reads approx. 140 °C:

• ‒ → Pull 5-pin connector off air mass meter (G70) with intake air temperature sender (G42) -arrow-.

If display jumps to approx. -40.0 °C:

• ‒ Press ⇒key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
• ‒ Switch off ignition.
• ‒ Renew air mass meter (G70).
• ‒ 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.

If display remains at approx. -40.0 °C:

• ‒ Press ⇒key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
• ‒ Switch off ignition.
• ‒ Check wiring using current flow diagram
  => Page 24-83

Checking wiring

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

• ‒ → Pull 5-pin connector off air mass meter (G70) with intake air temperature sender (G42) -arrow-.

• ‒ → Check wiring for open circuit between test box and 5-pin connector using current flow diagram.
      Contact 1+socket 26
      Contact 3+socket 27
      Wire resistance: max. 1.5 ω
• ‒ Check wiring additionally for short circuit to battery positive.
      Specification: ∞ω

If no fault in wire is detected:

• ‒ → Perform a resistance measurement on intake air temperature sender (G42) contacts 1 (signal) and 3 (earth)

→ 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 is in range A and corresponds to a resistance of 1.5...2.0 kω
• ◆ 80 °C is in range B and corresponds to a resistance of 275...375 ω

If the specification is not obtained:

• ‒ Renew air mass meter (G70).
• ‒ 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.

If there is no fault in the wiring and the resistance measurement values are OK.:

• ‒ Replace engine control unit
  => Page 24-150.