Chevrolet C128A: Brake Boost Regulation Pressure Sensor Above Maximum Threshold

What Does The Chevrolet C128A Code Mean?

This code means that the boost pressure sensor’s input signal offset is out of range.

Conditions for setting the DTC: Ignition ON. The ignition voltage is greater than 10 V.

What Are The Potential Causes Of The Chevrolet C128A Code?

Below are some potential causes of this DTC:

• ABS Boost Pressure Sensor Offset error
• Internal sensor failure is detected
• A short to battery is detected on the sensor signal circuit
• A short to ground or open is detected signal circuit
• The boost pressure being commanded is not being achieved
• Signal is erratic and changes faster than physically allowed

Recommended Parts

Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:

>>> WORKPRO 582-piece Crimp Terminals, Wire Connectors, Heat Shrink Tube, Electrical Repair Kit
>>> GM Genuine Parts 178-0857 Power Brake Booster Vacuum Sensor

Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!

Reference Sources

Chevrolet Volt Hybrid DTC – OBDG01 HYBRID Diagnostics Document, page 565.