What do you need to know about EGR codes?
A basic explanation of the valve works would probably help with the understanding of the diagnosis and repair of EGR codes. Exhaust gas recirculation is necessary for emissions purposes. Unfortunately, when it malfunctions it can actually push emission levels off the chart.
Why is EGR not needed at engine idle?
This feature reduces or eliminate engine ping caused by early detonation. This function is not needed at engine idle or when the vehicle is cold. This is why the EGR system is quite complicated and receives many inputs from other sensors that facilitate its operation.
What should I do if my EGR light is not working?
The repair of this condition is removal of the EGR valve and inspection of the passageway to check for a blockage. Each model vehicle has different procedures for clearing the passageway due to many different configurations of the system. Some Fords have a removable tube.
How can I tell if my EGR valve needs to be cleaned or replaced?
When the EGR valve is clogged or malfunctioning, it can cause irregularities in engine performance such as rough idling or valve knock, indicating that the EGR valve should be inspected. A trusted mechanic may be able to repair the EGR valve instead of replacing it.
How does the EGR valve in a car work?
A trusted mechanic may be able to repair the EGR valve instead of replacing it. The EGR valve works by routing a small amount of exhaust back into the combustion chamber. When the temperature in the combustion chamber is too high, nitrogen oxides are produced, which combine with elements in the atmosphere to form smog.
A basic explanation of the valve works would probably help with the understanding of the diagnosis and repair of EGR codes. Exhaust gas recirculation is necessary for emissions purposes. Unfortunately, when it malfunctions it can actually push emission levels off the chart.
What is the diagnostic code for exhaust gas recirculation?
P0402 OBD-II Trouble Code: Exhaust Gas Recirculation Flow Excessive Detected. Cost of diagnosing the P0402 code. P0402 is a diagnostic trouble code (DTC) for “Exhaust Gas Recirculation Flow Excessive Detected”.
How is exhaust gas recirculation ( EGR ) test done?
In an EGR system there is a pipe which comes off the exhaust manifold. The first EGR system tests you should perform are EGR idle tests. Both tests involve leaning the engine at idle by allowing exhaust gas to enter the engine through the EGR system. Apply vacuum to the EGR valve at idle.
What happens when the EGR valve is opened?
MAP sensor – if the EGR valve is vacuum controlled the PCM will read changes in the MAP sensor output in response to exhaust gas recirculation. The voltage from the MAP should increase when the EGR valve is opened. Above is a diagram of an exhaust gas recirculation system (Ford with DPFE).
What’s the diagnostic code for the EGR valve?
Several technical service bulletins for a wide variety of different makes and models have documented different problems associated with the EGR valve system. With some exhaust gas issues you might set a diagnostic trouble code of PO401 or P0402.
P0402 OBD-II Trouble Code: Exhaust Gas Recirculation Flow Excessive Detected. Cost of diagnosing the P0402 code. P0402 is a diagnostic trouble code (DTC) for “Exhaust Gas Recirculation Flow Excessive Detected”.
How to check for damage to the EGR system?
Checks the exhaust catalyst for damage or excessive back pressure on the EGR system. Removes EGR valve and temperature sensor to check for carbon holding the EGR valve open or the EGR bleed port not being blocked with carbon not allowing the valve to bleed off vacuum.
What causes the p0402 code on an EGR?
Code P0402 is triggered when the EGR temperature sensor sees more of a temperature change than the EGR has commanded to open. This is usually caused by the EGR backpressure control valve getting a burnt diaphragm from the exhaust backpressure over time or from a partly blocked catalyst. Need help with a P0402 code?
What does EGR stand for in exhaust valve?
EGR Valve stands for exhaust gas recirculation valve, which breaks down exactly what it does. Recirculating the exhaust does a few things for overall performance. First, it optimizes the fuel to air ratio without pulling in extra air from the intake.
Why does my check engine light come on when my EGR valve is stuck?
Whether the EGR valve is clogged, stuck open, or stuck closed, you’re going to get a check engine light. While the check engine light will usually point you straight to the EGR valve, it is possible that it might come on due to a symptom instead of a cause.
How does the EGR valve position sensor work?
The position sensor of the valve is linear and provides a signal proportional to its supply voltage (usually 5V). The EGR valve position sensor signal is set to increases in the direction of the opening of the valve. The position sensor is used for three main reasons:
EGR Valve stands for exhaust gas recirculation valve, which breaks down exactly what it does. Recirculating the exhaust does a few things for overall performance. First, it optimizes the fuel to air ratio without pulling in extra air from the intake.
Whether the EGR valve is clogged, stuck open, or stuck closed, you’re going to get a check engine light. While the check engine light will usually point you straight to the EGR valve, it is possible that it might come on due to a symptom instead of a cause.
The position sensor of the valve is linear and provides a signal proportional to its supply voltage (usually 5V). The EGR valve position sensor signal is set to increases in the direction of the opening of the valve. The position sensor is used for three main reasons:
How to reset exhaust gas recirculation ( EGR ) value with?
5)Using a soft bristled tooth brush, scrub the EGR Valve, spray further cleaner into valve if needed. Once all traces of carbon are removed, using a lint free cloth dry the EGR Valve. 6)Disconnect vacuum pump or OBDⅡ diagnostic tools.