Engine Speed Sensor: Testing and Inspection

Engine Speed Signal, Checking

If a malfunction of the RPM display at tachometer is detected, signal at the tachometer must be checked.
- Connect VAS5051 tester or VAG1551 scan tool. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks" under "Lighting and Horns"
- Read Measuring Value Block. Refer to "Scan tool Testing/Measuring Value Blocks (Function 08)/Reading" under "Instrument Panel"
- Select display group number 001 and perform a road test.

If the speed appears on the VAG1551 Scan Tool display but not via the speedometer in instrument cluster, the instrument cluster is faulty and must be replaced.

If no speed is indicated on the VAG1551 Scan Tool display either, the signal must be checked at multi-function connection at instrument cluster.
- Remove instrument cluster.
- Connect VAG1598 tester with VAG1598/25 adapter to the blue 32-pin connector.
- Perform an acoustic continuity check of the sensor and wire using the VAG1526 multimeter between terminal 28 and socket 9 (load Ground (GND))

Test
The beep signal of the resistance tester must switch on and off several times while the vehicle is rolled slightly forward and backward (approx. 1 m)

If the test is not OK, the wire connection to speed sender must be checked.
- Check wire connection according to wiring diagram.

If the wire connection is OK, the speed sender must be replaced.