850 (Speedometer Does Not Operate)
- Turn ignition on. Activate diagnostic test mode No. 3. See DIAGNOSTIC TEST MODE NO. 3 under SELF-DIAGNOSTICS. If speedometer needle moves to vertical position, go to next step and check speed sensor. If speedometer does not operate, replace instrument cluster.
- Turn ignition off. Raise and support vehicle. Disconnect vehicle speed sensor connector at transmission. See Fig 1. Connect an ohmmeter between sensor terminals. If resistance is 1700-1940 ohms, go to next step and check vehicle speed sensor ground connection. If resistance is not 1700-1940 ohms, replace vehicle speed sensor.
Courtesy of VOLVO CARS OF NORTH AMERICA.
- Turn ignition off. Connect an ohmmeter between vehicle sensor connector terminal No. 2 (Green/Yellow wire) and ground. If resistance is not zero ohms, check for an open circuit in wiring between connector terminal No. 2 (Green/Yellow wire) and instrument cluster 30-pin connector. If resistance is zero ohms, reconnect vehicle speed sensor and go to next step.
- Turn ignition off. Remove instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. Connect ohmmeter between instrument cluster 30-pin connector terminals No. 2 (Green/Yellow wire) and No. 3 (Yellow/Brown wire). If resistance is 1700-1940 ohms, replace instrument cluster. If resistance is not 1700-1940 ohms, check for open circuit in Yellow/Brown wire between instrument cluster 30-pin connector terminal No. 3 and vehicle speed sensor connector terminal No. 1.