Vehicle Speed Sensor: Testing and Inspection

Note:
If speed signal fails, Engine Speed (RPM) will be limited to 5320 RPM within 4 seconds, at full load.
For the following fault to be entered into Diagnostic Trouble Code (DTC) memory:
^ "00281 Vehicle speed sensor -G68 no signal" an Engine Speed of 4000 RPM must be maintained or exceeded for 4 seconds, at full load.

- Perform test drive
- Select "Read measuring value block" function 08 using VAG 1551 Scan Tool and input display group number 04. Refer to On-Board Diagnostics. Testing and Inspection

- Observe display value in channel 3.

Vehicle at stand-still:
^ Speed must always be 4 km/h (2.5 mph).

Vehicle exceeding 4 km/h (2.5 mph):
^ Speed value must be displayed

If speed value absent:
- Raise left front wheel off ground.
- Connect VAG 1598 Test Box, using VAG 1598/5 adapter cable, to ECM. Refer to VAG 1598 Pin Out Box Connecting Connecting and Testing VAG 1598 Pin Out Box

- Connect US 1115 LED tester or equivalent between terminal 18 (positive) and terminal 50 (signal).
- Switch ignition ON.
- Slowly rotate left wheel by hand.
^ LED tester must blink momentarily

If NO:
- Switch ignition OFF.
- Wait at least 30 seconds before disconnecting adapter cable from ECM.
- Switch ignition ON.
- Slowly rotate left front wheel by hand.
^ LED tester must blink momentarily

If YES:
- Replace ECM.

Engine Control Module Harness Connector:

If NO:
- Check for open/short circuit in wiring between ECM connector terminal 50 (Test Box terminal 50), and instrument cluster, using wiring diagram.