Tip & How-To about Mercedes-Benz E-Class

EGR how to fix

1.6c) EGR errors and how to fix

How to check? With the engine running it may be possible to force the EGR valve open by pressing on the diaphragm on the underside with one's fingers. Alternatively, disconnecting the vacuum line to the EGR and applying a vacuum to it (even sucking on it with your mouth) will determine if the diaphragm is split. If the valve opens in response to vacuum check that the upstream vacuum control valve on the vacuum line is opening in response to ECU instruction. Disconnecting an electrical EGR and applying a switching voltage (9 volts) across the connecting pins will cause it to open and the idling engine should falter or stall as the pressure drops in the intake manifold. If the unit clicks open but the engine is oblivious to its effect then it is likely that the passageways to the EGR are clogged up. Removal of the EGR assembly and examination of the ports and valve mechanism will reveal any carbon build up.


How to fix? Determinefirst that the fault actually lies with the EGR and not with any ancillary solenoid used to block vacuum to the EGR or a faulty DPFE sensor (see below). If the diaphragm is split then the EGR needs to be replaced. Most EGR problems are linked to carbon soot build up and this can be cleaned using a cloth, metal pick, wire brush and carburetor choke cleaner spray. If the exhaust feeder pipe is blocked this can be cleaned using a piece of coat hanger wire or a piece of frayed hand brake cable fitted to a drill as a rotary brush to remove dirt from the interior, even around corners. Some cars, Hondas are a good example, have an elaborate passage-way system to provide EGR exhaust gas to each individual inlet pipe runner. Later, Honda, having become aware of the occasional need to remedy blockages, provided EGR passageway assemblies with removable lid sections to allow cleaning access.



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How do I fix an EGR problem for a 1997 Mercury Mystique?


What you would need to do is find out which part is making the problem. By this, I mean the electric solenoids which supply Vacuum to the valve or the EGR valve itself or the EGR ports feeding the exhaust to be recirculated.

Free "check engine light" tests are available at major parts stores like Autozone.

You can test the EGR diaphragm by using Vacuum or by pushing the diaphragm open and putting your finger over the vacuum opening and sealing it off.

You may also have soot in the EGR valve prevent it from closing. Remove and clean the EGR.

Nov 04, 2013 | 1997 Mercury Mystique

1 Answer

what does the check engine code p0406 mean on my dodge caravan with a 3.3L engine?


P0406 - Exhaust Gas Recirculation Sensor A Circuit High
An improper voltage signal is sent to ECM through the valve

Early Models : The EGR valve control the amount of exhaust gas routed to the intake manifold. Vacuum is applied to the EGR valve in response to the throttle opening. The vacuum control the movement of the taper valve connected to the vacuum diaphragm in the EGR valve.

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Late Models : The EGR volume control valve uses a step motor to control the flow rate of EGR from exhaust manifold. This motor has four winding phases. It operates according to the output pulse signal of the ECM. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECM does not issue the pulse signal. A certain voltage signal is issued so that the valve remains at that particular opening.

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Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Engine hesitation

Possible causes
- Harness or connectors (EGR volume control valve circuit is open or shorted.)
- EGR volume control solenoid valve
- EGR temperature sensor and circuit

Possible solution
- Repair EGR harness or connector
- Replaced EGR volume control solenoid valve
- Replaced EGR volume control valve


Hope helps (remember to rate and comment this answer).

Mar 31, 2011 | Dodge Caravan Cars & Trucks

1 Answer

I have a 1990 corolla carburettor. When its at normal operating condition the car jumps and runs rough. When you accelerate the car runs well. It only plays up when at idle. But when cold it runs very well.


Check for a malfunctioning EGR valve. This valve is only selected to perform when the engine is warm. It has a vacuum diaphragm which can crack and lead to vacuum leaks. This will cause rough running. The EGR valve should be vacuum checked to see if this diaphragm is leaking. This valve can also stick open due to carbon deposits. When the valve sticks open, the fuel/air mixture is leaned out and rough running ensues. This problem is practically expected on a vehicle of that age.

Mar 21, 2011 | 1990 Toyota Corolla

2 Answers

engin light #po406 2005 ram quad cab


P0406 - Exhaust Gas Recirculation Sensor A Circuit High

Early Models : The EGR valve control the amount of exhaust gas routed to the intake manifold. Vacuum is applied to the EGR valve in response to the throttle opening. The vacuum control the movement of the taper valve connected to the vacuum diaphragm in the EGR valve.

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Late Models : The EGR volume control valve uses a step motor to control the flow rate of EGR from exhaust manifold. This motor has four winding phases. It operates according to the output pulse signal of the ECM. Two windings are turned ON and OFF in sequence. Each time an ON pulse is issued, the valve opens or closes, changing the flow rate. When no change in the flow rate is needed, the ECM does not issue the pulse signal. A certain voltage signal is issued so that the valve remains at that particular opening.

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Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Engine hesitation

Possible causes
- Harness or connectors (EGR volume control valve circuit is open or shorted.)
- EGR volume control solenoid valve
- EGR temperature sensor and circuit

Possible solution
- Repair EGR harness or connector
- Replaced EGR volume control solenoid valve
- Replaced EGR volume control valve
When is the code detected?
- An improper voltage signal is sent to ECM through the valve


Hope helps.

Mar 06, 2011 | 2005 Dodge Ram

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