The fault code P0406 is ‘Exhaust Gas recirculation (EGR), Sensor A Circuit High.’ When the powertrain control module detects high voltage from the exhaust-gas-recirculation position sensor (EGR), it triggers the fault code P0406. The EGR position sensors detect the position of EGR valve. The PCM monitors and adjusts the EGR valve using the sensor signal. The P0406 code will be recorded when the voltage sent by the EGR sensor to the PCM is greater than the range pre-programmed. The engine fault light will illuminate to alert the driver along with the P0406 code.
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What are the possible causes of fault code P0406?
The following are possible reasons why the PCM receives high voltage signals from the sensor:
- Faulty EGR Valve Position Sensor
- EGR valve faulty
- The EGR sensor circuit is prone to damage or loose connections due to damaged cables.
- Electrical signal weak
- Carbon buildup is excessive
- Vacuum leak in the line from the EGR valve
- PCM – A problem with the PCM
What are the symptoms of fault code P0406?
Most drivers will not experience any symptoms other than an engine fault light.
- Engine fault light illuminating
- Nox emissions values increase
- Engine performance decreases
- Engine knocking when accelerating suddenly and at high revs
- Fuel consumption increases
- Engine stalling occurs occasionally
- When driving, rev fluctuations can occur.
P0406 Arıza Kodu Nasıl Düzeltilir?
The codes must first be cleared, and then a road test is performed to see if they return. If the codes are returned:
- Replace the EGR valve
- If necessary, repair or replace the wiring harness
- Repairing weak electrical connections
- Replace the vacuum line
- Cleansing of excess carbon deposits
How Serious is Fault Code P0406?
The code will not stop the vehicle being driven safely. It can cause issues such as misfiring of the engine, stalling and difficulty starting. The fault should be repaired as quickly as possible.
