P0475: Exhaust Pressure Control Valve A

What does P0475 mean?

The exhaust pressure control valve is a flap in the exhaust: on older Navistar/Ford diesels a warm-up flap that raises back pressure when cold, on Ram and others an exhaust brake, on VW's 2.0 TDI a flap that drives the low-pressure EGR, and on Audi and Bentley a sound flap. P0475 is the general circuit fault of valve A, monitored like any output as CARB requires. VW's 2.0 TDI of 2015 sets it together with P0477/P0478, and the actuator electronics are replaced; Audi uses it for an electrical fault of the sound flap, Bentley for a shorted commutator in the flap motor. On the Navistar warm-up flap, a patent describes control to a target back pressure with the exhaust pressure sensor as feedback.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Check engine light on
• Flap without function: sound unchanged, rattling
• Diesel: longer warm-up, exhaust brake weak or EGR faults

Common causes

• High Flap actuator (motor or electronics) faulty
• Medium Wire or connector at the exhaust damaged or corroded
• Medium Control wire open
• Low Driver in the engine module

Likelihood is a general estimate across vehicles; your make and model may differ.