What causes code P0406?
The P0406 code is the result of the exhaust gas circulation (EGR) sensor A having a high circuit voltage. This code is set when the ECM identifies the EGR voltage is higher than the specified range, thus triggering the check engine light to illuminate on the vehicle dashboard.
How do I know if my EGR is working?
As you apply vacuum to the valve, check for diaphragm movement. Also, pay attention to engine idle. Idle should become rough or the engine should stall as you apply vacuum. If the plunger doesn’t move or the valve doesn’t hold the vacuum you apply, replace the valve.
What happens if EGR is stuck closed?
If the EGR system is clogged up, or the valve is stuck closed, the combustion temperature increases. This may cause pinging (detonation), as well as surging on light acceleration. In a diesel engine, a bad EGR valve is one of the causes of a black smoke. The Check Engine light might also come on in either case.
What sensors control EGR?
Some common sensors used for EGR control include:
- Temperature Sensors. Intake manifold and EGR temperature can be measured with commonly available temperature sensors.
- Pressure Sensors.
- Flow Sensors.
- Position Sensors.
- Gas Composition Sensors.
Does your BMW have a bad EGR valve?
BMW has issued at least one recall over EGR valves and valves in other models have been known to act up too. If you own a BMW you may want to familiarize yourself with the signs of a bad EGR valve so that you will know if your valve needs replacement. While there are many different kinds of EGR valves, the basic concept is the same.
How do you blank an EGR valve on a car?
If your EGR valve is vacuum operated blank the pipe using our blank and secure with the cable tie. Using our supplied blanking plate, gasket, bolts and locking washers, blank the hole on the exhaust manifold. Ensure the locking washers are installed between the bolt heads and the blanking plate.
Can a blocked EGR cause misfiring?
This malfunction of the valve or blocking of the exhaust port causes Detonation (also known as pinging or spark knock) causing misfiring or rough idle. Many examples can be found across the internet showing these EGRs completely blocked up with carbon; significantly reducing airflow to the intake.
What happens when carbon deposits in EGR valve?
Carbon rich recirculated exhaust gasses enter the EGR valve before the intake manifold, over time Carbon deposits gather in the EGR valve and can interfere with the operation of the EGR valve flap and can block air flow. Resulting in reduced fuel economy and vehicle performance.