# EGR & EVAP circuit is bad



## Agoudine (Feb 19, 2005)

Check engine light came on.
Code shown: 1005 (The EGR valve EVAP canister purge control solenoid valve circuit is open or shorted).
Visually it looks ok,but I think some of those little hoses may leak.
Please,suggest me the way to find out what exactly is causing problem.
EGR & EVAP systems are complicated for me. I could not figure out if they are connected. Is EGR control solenoid and Purge control solenoid one and the same thing?
Tell me also where to by those tiny hoses if I find which one is broken?
Altima 95 GXE / 96000miles


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## LONDONDERRY (May 19, 2004)

Agoudine said:


> Check engine light came on.
> Code shown: 1005 (The EGR valve EVAP canister purge control solenoid valve circuit is open or shorted).
> Visually it looks ok,but I think some of those little hoses may leak.
> Please,suggest me the way to find out what exactly is causing problem.
> ...


The EGR and EVAP systems are connected by various vaccum hoses. Inspec the hoses if the car cracked, then replace them with silicone one. Be carful not to get ones that have too thin of a wall or they will close up with you run the car. In addition, inspect the EGR valve for any cabon build up inside, which means you have to remove it which is simple, just make sure you have a new gasket on hand. You can either clean it out or replace it, as I did.


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## Agoudine (Feb 19, 2005)

Thank You!
The thick hose going from EVAP cannister valve was looking bad.I bought same diameter one and replaced it and erased the code,but when I cut the old hose along, inside I found a metal cylinder about a quarter of an inch long with a tiny hole.I am not sure what it is.Please tell me if I have to put it in the new hose?! Other hoses look fine and I wonder if the one I replaced was causing the problem!?I haven't driven the car yet, when I do I'll post again.


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## Agoudine (Feb 19, 2005)

Few minutes after I started driving the light came bach on. So,it is not that hose. I've read about this problem and I think,the EGR solenoid valve has to be replaced.Tell me if you know where to get a new one possibly inexpensive? Other hoses look good - I don't see reason to replace it.


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## jserrano (Oct 27, 2004)

Here is how the EGR solenoid valve works,










1. Port "B" goes to the air intake to pass atmospheric air pressure to the EGR and EVAP canister.
2. Port "A" goes to the EGR valve and EVAP canister.
3. Port "C" goes to a vacuum port on the throttle body to pass vacuum to the EGR and EVAP canister.

The ECU always powers ON the EGR solenoid valve to allow atmospheric air to flow from Port "B" to Port "A". This disables the EGR valve and EVAP canister.

During a small time interval, particularly when the car is rev'ing towards the 2000 - 2500 rpm, the ECU turns OFF the EGR solenoid valve and lets vacuum flow from Port "C" to Port "A". Then the ECU turns the EGR solenoid valve back ON. This basically causes the EGR valve to swirt a small charge of exhaust into the intake and it also swirts a small charge of fuel vapors from the EVAP canister into the intake. It is sort of a counter balance, a small intake leak is created and a fuel charge is added to counter the effect. Ultimately, the idea is to lower the cylinder temperature to allow better combustion.

It is possible that the EVAP canister could upset the EGR operation since they share vacuum connections.


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## Agoudine (Feb 19, 2005)

Thank you for posting such great reply and picture.
Since replacing hoses did not help, I bot an EGR solenoid valve from the dealership for $110 and replaced it myself. Check engine light did not come back since than. So,I believe,that was the problem.


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## Asleep (Jan 19, 2003)

next time, check the valve for proper operation while the vehicle is running. depress the bottom of the valve and the engine should stall. if it doesnt, the valve is bad.


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## jserrano (Oct 27, 2004)

Agoudine said:


> Thank you for posting such great reply and picture.
> Since replacing hoses did not help, I bot an EGR solenoid valve from the dealership for $110 and replaced it myself. Check engine light did not come back since than. So,I believe,that was the problem.


You're welcome. Also, a quick test of the EGR system can be done by feeling the EGR diaphragm underneath the EGR valve. Then slowly cycle the throttle cable up and down. You should feel the EGR valve move up and down. That tells you the EGR solenoid is operating and passing vacuum. Otherwise, it has a problem or the EGR valve is sticking.


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