OBD Code P0651

Sensor Reference Voltage “B” Circuit/Open

What’s mean?

OBD2 Code P0651 Definition:
These 5-volt reference circuits are independent of each other outside the PCM, but are bussed together inside the Engine Control Module (ECM). Therefore a circuit condition on one sensor 5-volt reference circuit may affect the other sensor 5-volt reference circuits. The ECM monitors the voltage on the 5-volt reference circuit.

Possible Causes

Possible causes of P0651
– Shorted sensor – Shorted sensor circuit – Failed ECM The Error code is generally activated on detection of the following conditions: The ECM has detected an out of voltage range on the 5 volt reference circuit 2

Possible Solutions