The DTC P0652 OBDII code indicates the Engine Control Module (ECM) has found a low voltage condition on a sensor designated as B. The referenced sensor is related to a differential or transmission. This code is usually stored with another code, which has to do with a more specific sensor.
The reference voltage for a circuit is usually 5V. This voltage is sent to the sensor through a circuit along with a ground signal. These sensors also have a variable resistor, which completes a circuit and provides the computer with an input signal.
In case the ECM does not get that voltage signal due to the low voltage condition, the P0652 code will be set.