Powertrain, generic · Auxiliary emission controls

P048E Exhaust Pressure Control Valve A Position Sensor/Switch Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

An exhaust pressure control valve is an electrically driven flap in the exhaust with a position sensor or end-position switch, usually inside the actuator. Valve A is the first such flap; Bentley's V8 assigns A to bank 1 and B to bank 2. Documented uses are the flap behind the particulate filter of VW's and Audi's 2.0 TDI, which raises back pressure for the low-pressure EGR, and the sound flaps of Audi and Bentley. P048E means valve A's position signal is above its window – an open signal pulled up, or a short to positive. VW's 2.0 TDI third generation of 2015 sets it together with P048B, P0475, P0477 and P0478: the flap is welded into the pipe, so with electronic faults only the actuator is replaced – an electrostatic-sensitive part that must be scrapped if dropped.

Likely causes

Actuator electronics (position sensor) faulty
Signal or ground wire open
Connector corroded
Signal shorted to positive

Symptoms

  • Check engine light on
  • Flap without function, exhaust sound changed
  • VW/Audi TDI: EGR fault P0401 possible

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€150–600
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

exhaust pressure control valve a position sensorexhaust pressure control valve asensor wiringengine control module

Related codes

P048BP048DP0475P0478P04A9

References: static.nhtsa.gov, law.cornell.edu.