If you encounter a 2010 and later Legacy or Outback with vehicle dynamic control that has DTC C0074 (with detailed code 5078) and/or DTC C0075 (with detailed code 5088 or 5099) stored in memory, there is the possibility that the cause is low battery voltage.
The learning value of the brake pressure sensor is recorded every time the ignition is cycled to the OFF position. If the battery voltage drops below a predetermined value before the recording process has been completed, the learning value is lost and a DTC will be stored, and the MIL turned on the next time that the ignition switch is cycled to the ON position. As an example, if the engine is started by jump-starting and the ignition is switched to OFF before the battery has regained sufficient voltage, the learning value will be lost.
Conduct “Zero setting of Pressure sensor” according to the following procedure (the vehicle must be parked with the wheels pointing forward):
Connect SSMIII to the vehicle and select the menu as follows:
* Each System Check
* Brake Control System
* ABS/VDC System
* Function Check Sequence
Press [Ctrl], [Alt] and [V] at the same time when the menu list “Function Check Sequence” is displayed. “Zero setting mode of Pressure sensor” will appear in the menu list.
Select “Zero setting mode of Pressure sensor.” Make sure that your foot is no on the brake pedal. Press “Yes” to continue. The screen will display “Zero setting mode of Pressure sensor,” followed by “Zero setting mode of Pressure sensor has started.” The screen will indicate when the process is complete.
Delete DTC C0074 and/or DTC C0075 from memory. If other DTC are present, refer to the applicable service manual for diagnostics.