P04A2 OBD II Trouble Code Exhaust Pressure Control Valve B High

How to quickly diagnose, repair, and info on symptoms and causes of a P04A2 trouble code which is an abnormal high condition with the B exhaust pressure control valve.

Symptoms of P04A2 OBD II Trouble Code

  • Malfunction Indicator Lamp (MIL) illuminated
  • Lack of power
  • Lack of engine braking
  • Longer than normal cold engine warmup time

Common Causes of P04A2 OBD II Trouble Code

  • Stuck Exhaust Back Pressure Valve
  • Restricted exhaust
  • Open in the ground circuit to the exhaust pressure sensor
  • Open in the signal circuit between the exhaust pressure sensor and the PCM
  • Short to voltage in the signal circuit to the exhaust pressure sensor
  • Exhaust Pressure Sensor faulty ? internally shorted to voltage
  • Plugged Exhaust Pressure Sensor sensing tube
  • Possibly turbocharger overboost
  • Possibly the PCM has failed (highly unlikely)