Knock sensor and knock sensor control, checking: Continuation

• Disconnect 3-pin connector from Knock Sensor (KS) 1 - G61-.
  Fig 1: Identifying Connector Terminals Of Knock Sensor (KS), 1 - G61-

  
• Connect multimeter US1119 (Fluke 83 or equivalent) to measure resistance between connector terminals, using adapters from VW1594 connector test kit.
  • Knock sensor terminals 1 and 2
  • Knock sensor terminals 1 and 3
  • Knock sensor terminals 2 and 3
  • Specified value: INIFINITY Ω

If resistance is OK (no continuity):

• Connect VAG1598/22 test box to Motronic ECM harness connector. See VAG1598/22 TEST BOX, CONNECTING .
  Fig 2: Identifying 3-Pin Harness Connector Terminals Of Knock Sensor (KS), 1 - G61-

  
• Check wiring for open circuit between ECM/test box and 3 -pin harness connector, according to wiring diagram.
  • Connector terminal 1 to ECM/test box socket 68
  • Connector terminal 2 to ECM/test box socket 67
  • Connector terminal 3 to ECM/test box socket 67
  • Specified value: max. 1.5 Ω
  Fig 3: Identifying 3-Pin Harness Connector Terminals Of Knock Sensor (KS) 1, G61

  
• Check wiring for short circuits between terminals of 3 -pin connector, and between connector and ECM/test box.
  • Connector terminal 2 to ECM/test box socket 68
  • Connector terminal 3 to ECM/test box socket 68
  • Specified value: INIFINITY Ω

If the wiring is OK:

• Loosen knock sensor and tighten to 20 Nm (15 ft lb).

If the malfunction still exists (stored in DTC memory):

• Replace Knock Sensor (KS) 1 -G61-.
• Check readiness code. See READINESS CODE .
• If Diagnostic Trouble Code (DTC) memory has been erased, or ECM has been disconnected, generate new readiness code. See READINESS CODE, CHECKING .
• Disconnect 3-pin connector from Knock Sensor (KS) 2 -G66-.
  Fig 4: Identifying Connector Terminals Of Knock Sensor (KS) 2, G66

  
• Connect multimeter US1119 (Fluke 83 or equivalent) to measure resistance between connector terminals, using adapters from VW1594 connector test kit.
  • Knock sensor terminals 1 and 2
  • Knock sensor terminals 1 and 3
  • Knock sensor terminals 2 and 3
  • Specified value: INIFINITY Ω

If resistance is OK (no continuity):

• Connect VAG1598/22 test box to Motronic ECM harness connector. See VAG1598/22 TEST BOX, CONNECTING .
  Fig 5: Identifying Harness Connector Terminals Of Knock Sensor (KS) 2, G66

  
• Check wiring for open circuit between ECM/test box and 3 -pin harness connector, according to wiring diagram.
  • Connector terminal 1 to ECM/test box socket 60
  • Connector terminal 2 to ECM/test box socket 67
  • Connector terminal 3 to ECM/test box socket 67
  • Specified value: max. 1.5 INIFINITY Ω
  Fig 6: Identifying Harness Connector Terminals Of Knock Sensor (KS) 2, G66

  
• Check wiring for short circuits between terminals of 3 -pin connector, and between connector and ECM/test box.
  • Connector terminal 2 to ECM/test box socket 60
  • Connector terminal 3 to ECM/test box socket 60
  • Specified value: INIFINITY Ω

If the wiring is OK:

• Loosen knock sensor and tighten to 20 Nm (15 ft lb).

If the malfunction still exists (stored in DTC memory):

• Replace Knock Sensor (KS) 2 -G66-.
• Check readiness code. See READINESS CODE .
• If Diagnostic Trouble Code (DTC) memory has been erased, or ECM has been disconnected, generate new readiness code. See READINESS CODE, CHECKING .