Sensor Reference Voltage ‘B’ Circuit/Open
Table of contents
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)
How do I fix code P0651 MERCEDES-BENZ?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- Mercedes Benz Code = 0093 Power supply (P0651)
Cost of diagnosing the P0651 MERCEDES-BENZ code
The cost of diagnosing the P0651 MERCEDES-BENZ code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
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.