SEAT Workshop Service and Repair Manuals

Notes:

• ◆ It is extremely important to keep to the tightening torque of 20 Nm to ensure the knock sensors perform perfectly.
• ◆ Only gold-plated contacts may be used when servicing the knock sensor connector contacts.

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ Test box V.A.G 1598/22
• ◆ Hand multimeter V.A.G 1526 or multimeter V.A.G 1715
• ◆ Adapter set V.A.G 1594
• ◆ Current flow diagram

Test conditions

• ● Self-diagnosis must have recognized a fault on one or both knock sensors.

Checking function

• ‒ Functional check of knock control and knock sensors read measured value block, display groups 14 to 16 and 24.

Checking resistances and wiring

• ‒ → Separate brown 3 pin connector to knock sensor 1 (G61) -1-.
• ‒ Measure resistance between the contacts 1+2, 1+3 and 2+3 at connections to knock sensors.
      Specification ∞ω

• ‒ → Separate black 3 pin connector to knock sensor 2 (G66) -1-.
• ‒ Measure resistance between the contacts 1+2, 1+3 and 2+3 at connections to knock sensors.
      Specification ∞ω

• ‒ → Connect test box V.A.G 1598/22 to control unit wiring harness.
• ‒ Check wiring between test box and 3 pin connector for open circuit according to current flow diagram.
          G61:    G66:
      Contact 1+socket    68    60
      Contact 2+socket    67    67
      Contact 3+socket    67    67
      Wire resistance: Max. 1.5 ω
• ‒ Additionally check wires at socket 67 for short to sockets 60 and 68.
      Specification: ∞ω

If no wiring fault is detected:

• ‒ Loosen knock sensor and tighten again to 20 Nm.
• ‒ Carry out test drive.

• During the road test the following operating conditions must be fulfilled:
• ‒ The coolant temperature must exceed 80 °C .

• ‒ When the temperature is reached, the operating conditions
      Idling
      Part throttle
      Full throttle
      Overrun
  must be attained several times.
• ‒ At full throttle the speed must exceed 3500 rpm.
• Again interrogate the control unit fault memory.

If the fault is still present:

• ‒ Replace knock sensor(s)