EGR valve trouble

mart609 · Post by **mart609** » Mon Jan 02, 2017 8:33 am

Yup thats my write-up.
I've had the EGR light come on a couple of times on my ludes and accord over the years but its never made the car splutter or run lumpy.

alinton · Post by **alinton** » Mon Jan 02, 2017 4:12 pm

Thanks for that K;

I took my EGR off today and cleaned it out, even though it didn't appear too bad. I then made and fitted a blocking plate.

However I'm still getting code 12.

I wonder if the solenoid is faulty? Does anyone know what resistance I should see across the pins on the EGR valve? Perhaps I could replace it with resistors to fool the ECU into thinking all was OK.

A

Post by **vanzep** » Mon Jan 02, 2017 7:29 pm

approx 5 volts with ignition on

Post by **Drax** » Mon Jan 02, 2017 11:00 pm

have you looked at the service manual for this? its on page 11-135

alinton · Post by **alinton** » Tue Jan 03, 2017 10:54 pm

I have, but it's a pretty chaotic fault-finding, needing a vacuum pump.

Who's got one of those?

How is it possible to actually delete the EGR, with it disconnected, so that the ECU is happy?

Has anyone worked out what the three pins in the EGR valve are?

alinton · Post by **alinton** » Wed Jan 04, 2017 11:28 am

Right, I've researched further and now I understand the system. The EGR valve is vacuum-operated, the vacuum coming from the EGR Control Solenoid Valve, which in turn gets its vacuum from the CVC valve.

I'd assumed that the solenoid was built into the valve, but not so.

The plug to the top of the EGR valve is merely a potentiometer, i.e. a position sensor to tell the ECU how much the EGR valve is open.

So, a failure of the system could be, in order from the EGR valve back:

1. Failure of the EGR Valve position sensor;
2. Failure of the EGR Valve itself (diaphragm rupture or jamming due to residue build-up);
3. Failure of control vacuum to EGR valve, which could be:
4. Failure of EGR Control Solenoid valve, or no +12v supply to it (fuse 19 or 23);
5. Failure of vacuum supply to EGR Control Solenoid Valve, because of:
6. Failure of CVC valve, or failure of any vacuum pipe anywhere in the system.

So once you see the order of things it should be easy to trace.

It also makes it obvious that it's not easy to fully delete the system. I also don't think its a good idea to just put in a blocking plate between the EGR valve and the inlet, since that would prevent the valve operating fully - it'd be pulling against a vacuum.

To block it, best to install the plate INSTEAD of the valve, and leave the valve connected but secured out of the way, so it still operates but does nothing.

I'll report back later!

A

K30DPC · Post by **K30DPC** » Wed Jan 04, 2017 4:12 pm

To delete it completly you will need reprogram ECU. This is possible but you'll need programable one and someone who you'll have to pay.

Mine with just blocking plate works fine and i never had EGR fault displayed since.

Vacum is used only for operating the valve. If i had to compare this to anything then i would say it is the same as garden hose. Your water supply would be exhaust gases, vacum would be your hand opening valve, and the sprayer would be intake manifold.
Now if the vacum will not open the EGR valve then exhaust gases won't travel into intake manifold
If your hand wont press the handle water won't go through the sprayer.
But if you close main tap can you open the sprayer valve? And this blocking plate would be your main tap.

I hope you'll get what i mean

BTW I'm not the only person who made this mode, just search online. Also there is a few online shops selling EGR blocking plates

Euroal · Post by **Euroal** » Wed Jan 04, 2017 4:15 pm

I have both a vtec solenoid and egr is it helps .

alinton · Post by **alinton** » Wed Jan 04, 2017 5:22 pm

I know K3 - but my point is that if you block the flange completely between the valve and the manifold, the diaphragm may have difficulty moving. But probably not actually, as the bottom of the diaphragm is open.

However, I'm fault finding mine. I removed the valve and capped the flange completely, so I could see the valve working. It seems that with the car idling, as soon as I plug in the EGR control solenoid it actuates and pulls up the diaphragm.

I don't think that's right. Surely the valve shouldn't open with the car just idling (and, in fact, with the engine stopped but ignition on)?

There seems to be positive supply to the solenoid all the time, which is correct, but there's also 0v - which I don't think there should be until the valve opens.

So, I think, either I have a wiring problem or an ECU problem.

Next step is to swap the ECU for my back-up one and see what happens.

A

K30DPC · Post by **K30DPC** » Thu Jan 05, 2017 4:05 am

Sounds right. Check your ECU as there may be visible damage to one of transistors. If this is the case then your ECU can be saved easily.