Resistance Check
NOTE:
Most models have a combination temperature sending unit (a resistance sender and temperature switch). Smaller terminal is resistance sender. Sending unit temperature values are stamped in the sender body.
Connect test resistor between sending unit wire and ground. Turn ignition on. Check for correct gauge readings. See BMW Gauge Resistance Specifications table. Remove sending unit and check resistance at position or temperature specified. If resistance is not close to specifications, replace sending unit.