ok I cleaned out my egr solenoid and it tests fine with voltage applied to it.

now, at idle with wires disconnected i testing the wires going to it I get 14 volts on power yellow side and around .37 to.40 fluctuating on the negative ground side

with wires connected across the terminals I get 14 volts on each sides. when I rev the engine around 2000 or so and hold it nothing changes, voltage-wise.

how does all this sound? I thought it was supposed to to to ground on the nonpower side? any help woud be appreciated

 

The car should die out or almost when you backprobe the frequency solenoid and apply a ground to the red wire.

 

I'm not sure if I did that. I'm a bit of anubwhen it comes to testing I had my meter on 20 voltage setting when I didall the above tests. Any test u think I should try feel free to throw it at me.

were the tests I did above worthwhile?

thanks in advance

 

There should be 12v at the black/yellow wire with the key in the on/run position. The other wire is the signal wire that goes directly to the ECU. When the ECU wants to open the EGR valve, it will send a ground signal to this wire. When you ground this wire with the engine running, the solenoid opens a vacuum signal on the #16 hose to the EGR valve and opens the valve. Try it out.

 

I tested it with battery voltage when I cleaned out the solenoid. The ports are closed with no voltage and open up with a "click" sound when I apply 12v to it. I confirmed this by spraying brake cleaner through it and again with lots of canned air through it. When closed the top nossle bleeds off through the filter port on top.

Then I used a multimeter to test for voltage with the key on and car off, like I said in my previous post, and got 12.71 or so on the yellow/power wire.
Then I tested with key on, car on, and got 14 v on the yellow/power side and .37 to .41 voltage on the other side/negative side I believe. These tests were with only the wires as they are without them being connected to the solenoid.

Then I connected the wires to the solenoid and with the car on and at idle I got 14v on power side and 14 volts on negative side. Again, this test was at complete idle.
Then I revved the engine to around 2000 and held it while watching multimeter and again checked both wires in succession for voltage and neither wire voltage changed.

Just to be sure, to check for voltage I put the negative lead on the battery with a test lead in between, and I used the red to check for voltage on any given wire that I tested above on.

Do these readings sound right ?

I believe there should be a change in the voltage on the return wire when the ecu tells the egr to work. Am I right ?

 

The EGR solenoid is switched, it is not the switch. There will not be a difference of potential.

The volt meter will only read a difference of potential.
Put a lead on the positive terminal of the battery, and the cable leading to the solenoid on the starter, you will read 0 Volts. It's not because there isn't voltage, it's because the difference of voltage between those two locations is zero. You know its hot, you know there is voltage there, but the meter will not read it because it does not detect a difference of potential.

With the EGR solenoid, there is power going to the solenoid, and power coming out of it. You will read the same voltage on either end of that connector because that wire is hot. Where you would want to check the potential would be down by the ECU or where the signal is grounded out to complete the circuit.

If you measure across the switch with the solenoid not grounded you will see the difference, displayed as ~14V with the engine running.
With the solenoid grounded out you should not see a difference, or 0V across the switch.

You need to measure across the switch to view the voltage change.

 

Okay, so with the car on at idle and normal operating temperature, I will put the red lead on the yellow wire and the black lead on the other side, with the wires connected to the solenoid and test that for voltage ? What readings should I see ? What should I see when I hold the revs at 2000 ?

 

Wow, I just a couple minutes ago bought an on demand diy from Mitchell. I had been buying alldata for all my vehicles for around the last year and while cheap in price the amount of data in them have been awful to say the least.

The mitchell gives great diagrams and detailed electrical testing that alldatadiy does not give.

This is what I just read Mitchell say. courtesy of AMERICAN HONDA MOTOR CO. of course.

1. Start engine and bring to full operating temp. Disconnect vacuum hose from egr valve and connect vacuum gauge. If vacuum does not exist go to step 3). If vacuum is present, disconnect 4-pin connector from control box, and recheck.

2. If vacuum is no longer present, inspect for a short to ground in Pink wire between EGR control solenoid valve and ECU. See Fig.8. If wire is okay, check for faulty ECU. If vacuum is still present, check vacuum hose routing of EGR system. If hoses are routed properly, replace EGR control solenoid valve.

3. Disconnect 4-pin harness connector at control box. Using jumper wires, connect battery voltage to terminal A of connector. See Fig.9. While observing vacuum gauge, ground terminal B of harness connector. If within one second vacuum gauge does not read approx. 8 in. HG, go to next step. If specified vacuum reading exists, solenoid valve is okay.

4. Turn off ignition. Check vacuum hoses to solenoid valve for improper routing, bad connections, leaks and restrictions. If hoses are okay, disconnect lower hose on EGR control solenoid valve, and connect a vacuum gauge to hose. Start engine and allow to idle. 5) If vacuum gauge reads 6-10 in. Hg, replace EGR control solenoid valve. If specified vacuum does not register on gauge, replace CVC valve.

 

Okay, so I did the tests and I was only getting 5 in. HG vacuum in step 3. after grounding terminal B. So I did step 4 and I was only getting 5 in. HG on lower hose so I connected a vacuum control device that cleaned out with brake cleaner and on that one I got around 9.25 in. HG vacuum so I used that but I'm only getting around 6.5 on the control solenoid using the good vacuum control device so does that mean the control solenoid is bad?

It says in step 3. that I should be getting 8 in. HG. I would think that when that opens I should be getting the same amount as what's coming out of the control solenoid, right ?

I'm actually thinking my ecu is bad so I'm wondering what test I can do to verify that the correct electrical output from the ecu is coming to those connectors ?

 

Ok so I failed my emissions test again. I have tested again and it appears that the Mitchell test above doesn't go far enough to isolate the problem. It asks you to ground the solenoid to see if it works and the solenoid in that test, tests out fine. But when I hook up a vacuum gauge to it and take off the ground I put on it and rev the engine to 2000 rpm and hold it there, the ecu appears to only momentarily grounds it then it appears to unground it as the vacuum gets released. Like I said, it's a very quick vacuum blip.

I then tested the connector for voltage after disconnecting it from the solenoid and just like I thought, the ecu momentarily grounds it as I get 12v voltage but then it releases the voltage and there is no longer any voltage on it.

I need to know how exactly the ecu manages to ground it. I believe there is a ground circuit and perhaps one of the grounds is not completely legit or maybe there is a short somewhere.

any help would be greatly appreciated

 

I've researched this and it doesn't appear that this particular problem has ever been fixed.

This is someone with the exact same issue in a prelude instead.

http://www.prelude power.com/forums/archive/index.php/t-250436.html

Just put the prelude and power words together. I had to put a space in between.