Circuit Description
WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The starter generator control module (SGCM) controls the transmission pump operation by applying voltage to the auxiliary transmission relay control circuit with an internal solid state device called a hybrid pump driver. When the SGCM is commanding the relay ON, the voltage of the control circuit should be high, near 12 volts. When the SGCM is commanding the relay OFF, the voltage potential of the control circuit should be low, near 0 volts.
The SGCM monitors the relay control circuits for the following conditions:
- Short to ground
- Short to voltage
- An open circuit
If the SGCM detects an improper voltage level on the hybrid pump driver circuit driver circuit, then DTC B3844 will set and the driver will be disabled.