egesteban

As titlte states, car is a 98 Ex, I have been dealing with CEL code P1457 and I have done everything I can to solve it with no luck. Today I took the cover off the two way valve assembly attached to the fuel tank and discovered that there was a hose terribly dry rotted. I will provide a picture pointing out which hose I replaced.

My question is, the hose I replaced goes from the "Y" vacuum joint and to the chassis to a nipple looking outlet. When I looked at the "Y" there was no vacuum hose going to one of the three ports on it. One end of the "Y" goes to the chassis of the car as stated above, another end goes to the Fuel Tank Pressure Sensor, and the other end is just open. Is there something supposed to be hooked up to it? I looked everywhere around and couldn't find anything that can hook up to it. Is it just a fresh air intake per say? Below is the image and the parts I am talking about.

Part 53 is the hose i replaced, and part 8 is the "Y" that has an empty port on it.

ezone

It's difficult to get a good (useful) schematic for the hoses part of the evap systems from the Honda site.
The diagrams I found do show one side of the pressure sensor is open to atmosphere and some use a T fitting (or Y fitting), but don't show actual hose routing.

I'll guess that hose is stuck into the frame to protect it from ingesting water.



Lookie at this bulletin for your code
http://www.s2ki.com/stor/library/TSB/a03-001.pdf
It may not apply to you if you aren't in the salt belt, but may be worth checking anyway.


HTH

egesteban

I understood what you said about the hose going to the frame to prevent water from getting in, but the third port on "Y" fitting is open to the environment. No hose, cap, filter etc, its just open and that's what is throwing me off.

As far as the article you linked me to, I have switched the ECU to a known good one, evap canister, the valve on top of the manifold, to no avail. NOTE: the parts from my car that were transferred to the other car do not throw any CEL and clear the monitors rather quickly.

I followed the P1457 troubleshooting procedure in the Civic Manual, and every single time it comes down to "Replace PCM". As far as I can tell, the ECU does not send the ground signal for the EVAP Purge Control Solenoid Valve. Like I said, I have tried those parts already from a known working car that does not experience the same symptoms and can't figure out what else to do.

Hopefully you can shed some light on me.

ezone

You didn't mention changing the bypass solenoid.
In the bulletin linked, the windings of the bypass solenoid become a short-circuit and damage the output driver in the PCM. If yours were shorted, it would kill any "good" PCM as soon as the unit tries to activate the solenoid. It wouldn't necessarily be immediate, as the EVAP functions don't begin immediately at startup.


If you already know the individual pieces are good, what about the wiring to each one?

With a good wiring diagram, some working knowledge of electricity, and a few simple tools (jumper wire and paper clip), you can disconnect the PCM and carefully activate each solenoid manually from the PCM wire harness.

egesteban

Sorry I forgot to mention, but I have changed the bypass solenoid also. And the PCM that was in my car, that according to the manual was bad, functions properly on the other car. I know that EVAP functions don't begin immediately, they work under certain conditions. And it has been about a week of the other car driving with the "bad" ecu, and theres no CEL(on my car it usually takes a day or two max for the CEL to come up), and the EVAP monitor cleared when I use my scanner on it.

I have a wiring diagram, I have tools and knowledge of electricty, I have checked the wiring and it is good, I have manually jumped the pins on the PCM connectors and both of the solenoids in the engine bay activate.

By the way, the car has a 98 B18B1 LS swap, I doubt that changes anything judging from having studied manuals for both the Civic and the Integra, and also following the diagnostic procedure for both Civic and Integra with every time having it narrow down to a bad PCM.

ezone

How long has this swap been running without setting this particular fault code?
Ok, you gotta be missing something then.
Problem doesn't have to be electrical to set the code.

Just an example: I've seen a ton of cap and neck issues over the years, the threads bind so the cap doesn't screw down all the way before it clicks.



Have you done the physical inspections, like

Manually activate solenoids to seal the tank, monitor the FTP sensor voltage, and apply vacuum until the FTP reaches the specified voltage, then hold.......does the tank actually hold vacuum without decaying rapidly?


Smoke test the tank?
I have used smoke, and I have used soap with slight pressure (1PSI or less) to pinpoint leakage in tanks before.

egesteban

I have had the swap in for about a month, and it has been doing it since. With the original motor I am not sure if it had that code because the previous owner had removed the secondary o2(he had a test pipe) and I always thought the CEL was just for that, my wrongdoing was never actually checking for any other problems.

How would I go about activating the solenoids to seal the tank? I have applied vacuum to the FTP sensor itself and it shows the appropriate readings according to the Honda manual.

I would appreciate if you can tell me how to activate the solenoid to seal the tank and how do I apply vacuum to the tank itself?

By the way, thank you very much for your help, your time means a lot.

ezone

At work, all I have to do is connect the scanner and let it run the EVAP system self test. This does the entire test in a few minutes from start to finish.
If it doesn't pass, there is a lot of manual testing to do though.

I can manually activate each solenoid individually through the scanner if needed.

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Some of the info should be in a good service manual.
Please forgive me if I kinda blur this, I tend to lump many of the various versions together.

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First: With the engine running, apply power and ground to the PCS. Does it pass engine vacuum through the valve? Lots (large volume) of vacuum with no restriction?

Is it even connected to a manifold vacuum source? You said it's a swap, anything is possible.

If the valve can't flow sufficient volume to pull the tank into a vacuum within a specific time period, the system judges that as a leak. (Restricted purge valves have been an occasional problem on 7th gens.)

The volume in the gas tank during an evap test might be 10 gallons or more of empty space, and the system has to put it into a vacuum within just a few seconds. A restriction slows that down significantly and can cause a fail.
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I might manually activate the solenoids as needed with jumper wires a. Apply vacuum with a hand pump. Watch sensor voltage.


The PCS controls vacuum to the canister and tank. Valve is normally closed until powered.

The bypass solenoid separates the tank and canister areas. One mode isolates the canister, the other mode connects tank and canister together.

The CVS vents the canister. Valve is normally open until powered.

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locate an actual diagram for your original car and engine combo as they are not all alike (also, Calif version may not be the same as the rest of the US):


Note your T fitting on the FTP sensor in the diagram here. One end seems to go nowhere.

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Here's another TSB to check out
http://engine-codes.com/uploads/honda/99-075.pdf

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EDIT: I can't read.

egesteban

I have done that test, and when I apply ground to the solenoid the vacuum on my gauge goes to about -18-20(which to my understanding is normal vacuum for a motor at idle, at least in my SRT-4 it is), that solenoid goes mounted directly on the intake manifold and has a hole for the spout of the solenoid to go into.

What I don't understand is why the PCM doesn't send the ground signal to actuate the PCS valve. I lift the car, start it and let it warm up until the fan comes on, then I put it in first gear and accelerate to 3k RPM's, and nothing happens, at that point the valve should open.

I have tried that test with multiple PCM's with the same result.

The BLK/YL wire has 12v constantly, the RED/YL never switches to Ground signal.

On my scanner(iOBD2 for iPhone) it has a menu that lets you test for evap leaks, I push "Test" and it says "Command sent" but nothing ever happens nor does it tell me anything.

Also I don't have a scanner that actuates the solenoids. I have to do it manually.

Do you mean the line that runs from the rear to the front of the car and goes into the canister? If so, I already did that, I plugged one end and applied vacuum to the other and it held vacuum for longer than 1 minute. It wasn't really dropping at all.

As for the other tests, I will do them on my next day and report back with results, or hopefully, a solution.

Question: If say a test didn't pass within the EVAP system, the monitor wouldn't become to "ready", would that make the ECU not send the ground signal to the PCS valve to open up?

egesteban

Also, as far as I have read the P1457 is related to canister area, and the P1456 is for tank area.

ezone

Right.

Can you manually activate that solenoid from the PCM harness inside the car? Got continuity?
Try connecting a LED test light to it (the ground wire) and drive around. Or a duty cycle meter.
The PCS valve normally operates on a duty cycle, it's not a continuous ON or OFF state.

Um, I don't know a darn thing about the iOBD2 app thing myself, but I suspect it isn't doing anything.

Got any documentation that tells what vehicle platforms that particular test will work with?
I meant the line between the bypass/2way and the tank. See the diagram.
The bypass and 2way are usually on top of the tank, drivers rear corner area.

Do you realize just how long you'd have to pump a hand vacuum pump in order to get any vacuum on a half empty gas tank?
We're talking cubic feet inside a tank, not cubic centimeters.

If you pumped up a vacuum right away, then the bypass valve was closed and blocking the tank.
I'm guessing this is what happened.
That means you checked the lines between the front of the car and the valve, not the tank itself.

ezone

Fock. I'm an idiot.

EDIT: Told ya I kinda blur the systems all together.

ezone

Then you should be able to clamp off the line to the rear, power up the CVS, pump a vacuum in the canister, and see if it holds vacuum.

Usual culprit is CVS that either won't click or leaks, and here in the rust belt I see them rusted apart at the seams when mounted under the car.

egesteban

Yes I can, if I ground a pin on the ecm, it activates the valve(Can't recall which pin). And there is also continuity between the PCM side harness and the engine harness.

I do not, I also suspsect that "test" does nothing.

I didn't that pump line. I was mistaken, applied vacuum to the line that from the 2-way valve to the front of the car to the canister. My mistake.

egesteban

The CVS holds perfect vacuum when activated as per the Honda manual.

ezone

Try connecting something to monitor this while you drive around.
Test light, meter, something you can see from the driers seat.

IDK what enable criteria are off the top of my head right now.

May need more of a load than freewheeling in the air?

egesteban

I can connect a meter to it and drive around and see what it shows. '

Supposedly as far as I have read the criteria for that valve to pulse on command of the PCM is at above 1mph and 3k RPM's and the test manual tells you to jack up the car and do that. And that's where the manual tells me to replace the PCM every single time.

egesteban

Question regarding my first post. Would that line that was torn up and I replaced could have been the culprit? I replaced it and went to drive the car, all the monitors set in green after a few miles, except for the EVAP monitor. Does that one just take longer to set or am I right in thinking that wasn't the problem?

ezone

Redo:
DTC P1457
1. Turn the ignition switch to ON (II).
2. Leave all solenoids off, and clamp the vacuum
hose between the EVAP two-way valve and the
fuel tank.
3. Disconnect the vacuum hose between the
EVAP canister and the two-way valve at the
two-way valve port.
4. Attach a hand vacuum pump to the port on the
two-way valve. Note the FTP sensor voltage
reading.
5. Apply 2 inches of vacuum to the two-way
valve, and watch the FTP sensor voltage. If the
voltage drops more than 0.05 V in 20
seconds, replace the two-way valve and the
bypass solenoid valve, and retest.




Can your scanner get raw generic data?
As in TID$2D, etc.?

egesteban

Yes it can. What should I look for? (It all seems like jibberish to me when I look at it.)

egesteban

What does "leave all solenoids off" mean? As in disconnect them? Remove them from the vehicle? Kinda lost there.

ezone

What about under 3k? Some people may drive so eco they might never hit 3000 PRM.



I see a thing here saying
PCS duty controlled --> coolant temp has to be over 154*F and IAT over 32*F , VSS over 0 MPH.

OR AC clutch on + CTS over 160F

You got good coolant temp on your scanner?

Shouldn't be, that line looks like the one that is open to the atmosphere anyway. If so, it could missing and not affect anything.

EVAP MONITOR only runs after a cold soak, the tank test is done within about 30 seconds after a cold start.
Purge (PCS) happens while driving the car normally though, most of the time.

ezone

Hang on. I'll send that in a PM.


Electrically at rest. Not activated.

egesteban

Yes it displays coolant temperature. Fan comes on around 190-195, can't recall exactly where. Seems normal to me.

Thank you.

ezone

Secret decoder ring sent.




HTH

egesteban

LOL secret decoder ring received. I will take a look at it and hopefully come to an answer.

THANKS A BUNCH. I have posted on another honda fourm and got nowhere, hardly any replies. Your time is greatly appreciated.

ezone

YW. Just gotta put up with me being a smartass when the mood strikes and I have brainfarts on occasion:

Or dumbass. Whatever.

egesteban

I will gladly put up with smart assness lol you're being very patient and VERY informative. I feel like a dumbass asking **** on forums, I usually search and am able to figure out problems but this issue has me stumped.

egesteban

Update:

Ran the test in red lettering you told me to, where I apply vacuum to the two-way valve and monitor the FTP sensor. It passed.

As far as the TID readings, the CEL isn't currently on right now because last I worked on the car I switched PCM's and it hasn't came back. BUT the Evap monitor readiness test has not cleared.

I checked the EVAP three way valve that goes from the evap canister control vent shut valve, I removed it and I can blow straight through it, and when I shake it, I can hear something rattling inside of it. Is that normal? (being able to blow straight throught it, and the rattling noise inside of it)

ezone

Maybe you should wait and see what (if anything) comes up if/when the code resets, instead of pulling your hair out...
Maybe it can lead to a more direct approach.



You're gonna love this... The online service info skips that 3 way valve.... Skips from page 270 to 294 (2 way valve test). I assume what you want to know lies in that missing info.


I'll venture a guess or two:
1) If it rattles, maybe it will block one of the ports if it is flipped upside down?
2) It is connected to the Canister Vent Shut valve vent port in the schamatics, so I doubt it has anything to do with your code as long as the CVS valve works correctly.

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Since there are about 6 different versions of this emissions setup shown in the service manual, tell more about your car:

Engine type D16Y? (something)?
coupe/sedan?
EX LX DX or what?
trans type?
emissions type (Fed or Cali)?