Knock Sensors, Checking

Knock Sensors, Checking


NOTE:
- Knock Sensor (KS) 1 -G61- and Knock Sensor (KS) 2 -G66- cannot be checked electrically.
- Use only gold-plated terminals for repair of knock sensor connector terminals.
- To function correctly, it is important that the knock sensor tightening torque of 20 Nm (15 ft lb) be maintained.
- When troubleshooting, check the knock sensor harness connector terminals for corrosion.


- Connect VAG1551 or VAG1552 Scan Tool (ST) and press buttons -0- and -1- to insert "Engine Electronics" address word 01 (engine running at idle). Refer "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG1551 or VAG1552 Scan Tool"Testing and Inspection

Indicated on display


Rapid data transfer HELP
Selecting function XX


- Press buttons -0- and -8- to select "Read Measuring Value Block" (scan tool function 08), and press -Q- button to confirm input.

Indicated on display


Read Measuring Value Block
Insert display group number XXX


- Press buttons -0-, -1- and -5- to input display group number 15 (015), and press -Q- button to confirm input.

Indicated on display


Read Measuring Value Block 15 ->
1 2 3 4


- Check specified values for knock control for bank 1 (display fields 1-4):
Engine speed for test: 3300 RPM







- Press -3- button to advance to display group 16.
- Check specified values for knock control for bank 2 (display fields 1-4):
Engine speed for test: 3300 RPM







- Press -> button to advance program sequence.
- Press buttons -0- and -6- to select "End Output" (scan tool function 06), and press - Q- button to confirm input.

Checking knock sensors
- Disconnect applicable knock sensor harness connector (near fuel rail under center engine cover).







- Connect multimeter US 1119 (Fluke 83 or equivalent) and check for short circuits between knock sensor connector terminals.
There must be no continuity between any of the 3 terminals.

If there are no short circuits, but knock sensor signal is faulty:
- Check readiness code. If Diagnostic Trouble Code (DTC) memory has been erased, then generate new readiness code.
Refer "Monitors, Trips and/or Drive Cycle (Readiness Code)/Checking, Readiness Code" Testing and Inspection
Refer "Monitors, Trips and/or Drive Cycle (Readiness Code)/Generating, Readiness Code" Testing and Inspection

Checking wiring between knock sensors and ECM
- Connect VAG1598/19 test box to Engine Control Module (ECM) harness connector. Refer "Scan Tool Testing/Scan Tool Connecting and Initial Checks/VAG1598/19 Test Box, Connecting" Testing and Inspection







- Check wiring for open circuit, short circuit to B+ or short circuit to Ground between applicable knock sensor harness connector and ECM.







Knock sensor 1 -G61- (Cyl. 1-4)

Knock sensor harness VAG1598/19 test box socket (ECM terminal)
connector terminal
1 A20
2 A19
3 D11

Knock sensor 2 -G66- (Cyl. 5-8)

Knock sensor harness VAG1598/19 test box socket (ECM terminal)
connector terminal
1 A21
2 A19
3 D11

If there are no open or short circuits:
- Replace knock sensor.
- Check readiness code. If Diagnostic Trouble Code (DTC) memory has been erased, then generate new readiness code.
Refer "Monitors, Trips and/or Drive Cycle (Readiness Code)/Checking, Readiness Code" Testing and Inspection
Refer "Monitors, Trips and/or Drive Cycle (Readiness Code)/Generating, Readiness Code" Testing and Inspection