P0477 - OBD II Trouble Code

Our automotive experts have put together the following information about the P0477 diagnostic trouble code. We've provided the common symptoms that occur when this code is set along with the frequent repairs that address the issues related to the P0477 code.

What Does P0477 Code Mean?

OBD-II Code P0477 is defined as a Exhaust Pressure Control Valve "A" Low

The Exhaust Pressure Control Valve controls exhaust back pressure during engine warmup. If the engine control module (PCM) determines there is an incorrect signal from the Exhaust Pressure Control Valve, the PCM will set code P0477.

Common Problems That Trigger the P0477 Code

• Exhaust pressure control valve failure
• Powertrain Control Module (PCM) failure
• Wiring issue