Clutch Switch: Testing and Inspection

Clutch Vacuum Vent Valve Switch, Checking:
- The Clutch Vacuum Vent valve Switch F36 informs the ECM when the clutch is being engaged or disengaged.
- This prevents the engine from jolting when disengaging and engaging.
- It also prevents the engine from racing during clutch disengagement when the cruise control system is switched ON.

Special Tools, Testers And Auxiliary Items:
- VAG 1551/1552 Scan Tool with VAG 1551/3 adaptor cable
- VAG 1598/18 Test Box
- Fluke 83 Multimeter or equivalent
- VW 1594 Adaptor kit
- Wiring diagram

Test Sequence:
- Connect Scan Tool VAG 1551/1552
- Switch ON ignition but do not start engine
- Press 0 and 1 buttons to select address word 01 "engine electronics"
Display will appear as shown:

Rapid data transfer HELP
Select function XX

- Press 0 and 8 buttons to select Function 08 "read measuring value block"
- Press Q button to enter input
Display will appear as shown:

Read measuring value block HELP
Input display group number XX

- Press 0 and 6 buttons to select "display group 06"
- Press Q button to enter input
- Observe display in channel 2
Display will appear as shown:

Read measuring value block 6 -->
0 kh/m 0 0 0 0000000 255

Specification: 0 0 0

- Operate clutch pedal
Left-hand display value must change to 1
Display will appear as shown:

Read measuring value block 6 -->
0 kh/m 1 0 0 0000000 255

Specification: 1 0 0

If specifications not obtained:
- Press -> button
- Press 0 and 6 buttons to select Function 06: "End data transfer"
- Press Q button to enter input
- Switch OFF ignition
- Disconnect Clutch Vacuum Vent valve switch -1- connector
- Measure resistance at switch terminals
Specification:
Clutch disengaged: max. 10 ohms.
Clutch engaged: infinite ohms.

If specified resistance not obtained:
- Replace Clutch Vacuum Vent valve Switch F36





If specified resistance obtained:
- Connect VAG 1598/18 Test Box to ECM wiring harness





- Check wiring for open circuit between VAG 1598/18 Test Box and connector using wiring diagram:
Terminal 1 + socket 33
Terminal 2 + socket 17
Wire resistance: max. 1.5 ohm

- Check for shorting between wires
Specification: infinite ohms

If no malfunction detected
- Replace Engine Control Module J248