P0651 MERCEDES-BENZ – Sensor Reference Voltage ‘B’ Circuit/Open

P0651 MERCEDES-BENZ Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

P0651 MERCEDES-BENZ Possible Causes

Check other codes,Faulty Sensor,Sensor harness is open or shorted,Sensor circuit poor electrical connection,Faulty Engine Control Module (ECM)

P0651 MERCEDES-BENZ Description

This fault code is stored in the Engine Control Module (ECM) when a malfunction occurs with the sensor supply voltage circuit. The engine control module outputs a five volt supply voltage to certain sensors. Many components share the same five volt supply. If fault codes exist for multiple components which operate with a five volt supply the wiring from the ECM and the ECM itself should be tested. Also each component should be disconnected in turn to identify a faulty component pulling down the supply circuit.