Speedometer Test
- Ensure that all fuses are okay. Start engine. Using trip computer function switch, select average vehicle speed display to zero. Drive vehicle. While at average cruise speed, push and hold trip computer RESET button for more than 2 seconds. If instantaneous vehicle speed is displayed, replace speedometer. If instantaneous vehicle speed is not displayed, go to next step.
- Turn ignition off. Remove instrument cluster. Disconnect both instrument cluster 26-pin wiring harness connectors. Inspect connector pin terminals for damage and repair as necessary.
- Connect Red 26-pin connector to Circuit Tester (VAG 1598). Reconnect Green connector to instrument cluster. Place transmission in Neutral. Raise and support vehicle. Position voltmeter on A/C scale.
- Turn ignition on. Rotate left front wheel. Measure voltage between circuit tester test pins No. 8 and 14. If voltmeter reads 1.0-4.5 volts, go to next step. If voltmeter does not read 1.0-4.5 volts, replace VSS or repair open circuit.
- Connect voltmeter negative lead to circuit tester test pin No. 14. Connect voltmeter positive lead to VSS terminal No. 2 on instrument cluster. See Fig 1
Rotate left front wheel. If voltmeter reads 1.0-4.5 volts, replace speedometer. If voltmeter does not read 1.0-4.5 volts, replace printed circuit board.
Courtesy of AUDI OF AMERICA, INC.