1457 evap code coincidence or not...
 

Have an 01 Accord.
Recently did a Timing belt job.
I mention this because even before I completed the job I had to put the valve cover, ps/air, belts, and engine mount back on (because at the time I couldn't remove the stubbon Crank pulley bolt till a later date).
Shortly after, the above code showed up.
Looked at any area that I was working around but can't find any lose hoses/connections. Also applied 12v to the Purge solenoid at the
Canister. It activates. Should there be power at the molex connection when the ignition is on or is one lead sunk to gnd. as there is no power at the connector?

Thanks,

Try using the search functon. Look for "P1457"
I found this thread that look slike it should help: https://www.hondaaccordforum.com/for...ighlight=P1457

I'm pretty sure there should be battery voltage always (whenever the key is ON). The ECU switches the ground side of the circuit. That's Honda's traditional way of doing things.

If you don't have battery voltage there, you may want to check the same at any other solenoid around the engine. The one exception I can think of is the VTEC solenoid. That one is grounded through it's mounting bolts, and has only 1 wire.

The remaining solenoids in the EVAP canister system are around the canister. Which is located underneath the car, roughly below the left-rear seat.

Thanks.
Actually I mean't to say I was checking the Vent valve power connector at the Canister.
I will check for battery voltage as you described.
Once I find the hot terminal I'll check the other terminal (gnd) to see if the ECM switches to gnd.

I still can help but think it was something I did during the initial timing belt
work... Initially I did not disconnect the battery when I removed the grounding engine mount strap. Do you think that could've affected the PCM?
Initially I got 3 codes (two evap and one AT abnormal ??) after attemping the belt job the first go around. :confused:

So did you clear the codes & now only P1457 comes up?

One solenoid valve in that system is the purge valve, up in the engine compartment. If you're looking for a plausible scenario where you left something disconnected, it might be THAT one. I think it's actually on the firewall, back behind the intake manifold.

When I checked it before 1457 was the only code activated.
However, this morning I had the code reader connected while driving in and saw the original 3 codes activated (see below).

P0700 Transmission Control System
P1739 automatic trans-axle concerns

These were the 3 that came on shortly after the first attempt at the timing belt job.
At that time the only thing I did was loosen the valve cover, remove the PS & and Alt. belts, drain the coolant, remove the engine mount and place a Jack under the oil pan and slightly support the engine in preparation for the T belt replacement. When I realized I couldn't remove the Crank Pulley bolt (at that time) with an 1/2" Impact gun, I then put everything back together till I got a 3/4" gun...

No signs of the car running poorly ( at this time)...

Strange...:confused:

Well, I won't pretend to know much about automatic trannys, so I'll stick to P1457.

If it's related, the only thing I can think of is the EVAP purge valve since it's located in the engine compartment. Check that it operates.

If it's just a coincidence, one of the most common failures is the EVAP vent-shut valve. It's located on the outboard end of the EVAP canister. Unplug it & provide power directly from a battery. Long jumper wires, or remove the valve & carry it to the engine compartment.

When I got that code, I checked a couple valves and found that the vent-shut valve would not even click with battery voltage. New valve fixed it.

I'll try to find a long write-up that I did (it was a long time ago).

Thanks Jim,

I previously did connect an external 12V supply to the canister vent valve.
It does click.
I'll keep troubleshooting...

In my case the valve was corroded badly & didn't click. It's possible yours clicks but doesn't really work. Use a MityVac or something to verify the valve actually opens & closes when it clicks.

That code actually means the canister & associated hoses & stuff is not airtight like it should be. Possibilities can include vacuum hoses disconnected from their proper places. Or even a crack in the canister itself.

Potentially the most troublesome possibility is a bad fuel tank pressure sensor. That's used to measure whether the tank & EVAP canister are airtight. If that sensor's bad, you have to drop the fuel tank.

I just dug up an old post of mine & copied it into the DIY section for you.

https://www.hondaaccordforum.com/for...d.php?p=180393

Would anyone have an idea what could trip p0700,p1457,p1739 all at the same time - bad ground ??
Car is running fine.

I've removed the motor mount grounding strap and cleaned the connection points.

sounds like 2 different issues

evap system leak p1457 ....2 way valve, bypass solenopid valve, shut valve , hoses ..??

tranny issues..

P0700 sets anytime a 17xx series code sets. It is a generic trans code. Your code description is for the 3rd pressure switch. You should be able to search on here for it.

It may be two different issues. However, as I stated previously, it all started after an attempt to perform a timing belt change. Just wondering if lifting the engine slightly loosened a connection,etc.? Have looked, but found nothing. Will look again.
Just trying to do some analytical troubleshooting before trusting the DTC's.

Within the engine bay, the part that would cause P1457 is the purge valve. It's bolted to the intake manifold, #8 in the picture. Check the vacuum hoses to/from that valve. There SHOULD be enough slack for a fair amount of engine movement, such as you'd get while driving. Maybe a hose is just old & brittle & cracked?

http://www.hondaautomotiveparts.com/...13S840_E01.gif

This past weekend I checked all the lines around the purge valve and CVS. All appear to be ok.
I also tested the purge valve with 12v and a mighty vac. It operates
and holds and releases vacuum when powered up/down.
I then turned the ignition on and there is 12v at the purge valve plug.
However, I do not see ground continuity at any time.
Does the ECM send the ground sink signal at any particular time or is it random?
Thanks

I'm sure there's logic to it, but I don't know the scheme. A Helm repair book for your year probably has some information.

Not true. I had the p1739 set but no p0700.

I have just recently gone through a p1456 ordeal myself (similar to 1457) and have investigated most of these valves in great detail.

Pretty much all of the valves are operated by the ECM/PCM providing the ground connection, the 12V is applied by other means.

Also, I am very sure that the service manual stated that the purge valve is always open *after* the car reaches a certain temperature. So if you tested it below that temp then your readings or 12V (yes) and ground (no) are exactly as expected and do not indicate a problem.

Let the car warm up, then test. From my own experience I can tell you that once warm there should be a pulsing vacuum on the line from the purge valve to the canister. Just put your mightyvac on this line after unplugging it from the canister and take a measure. I believe it was about 20 inHg vacuum, but I could be wrong.

Anyway, as everyone else has already said, this is the only part of the evap system you could have touched doing the TB work you described. So go under the car, unplug the purge valve hose from the canister, test that this hose can hold vacuum with engine off, and that it produces vacuum with engine on and hot.

With no voltage applied to the canister vent valve it's normally open as it should be.
When I apply 12v to the cvs it holds vaccum as it should.
However, when I remove the 12v it still holds vaccum (solenoid doesn't drop out). I assume this isn't correct...?
Thanks

Hope this is of some use to you: (I know you probably don't have Honda's outdated PGM Tester :D, but AllData tells me to go directly to this TSB when I look up the EVAP bypass solenoid [aka Vacuum Cut Valve Bypass Solenoid]. I don't know why they require the PGM tester. I can't see any reason why you can't remove the solenoid and apply power to it to test it. From experience, I've found it easier to just disconnect all the lines from the canister and drop the whole assembly down, valves and all. Much easier to work with on a workbench. Also, let the canister vent for an hour or so, then you should be able to safely use a torch to heat up stubborn screws and remove them. My P1457 ended up being the EVAP Vent Shut Valve, but nonetheless, the repair procedures are similar.)

I also included Honda TSB 01-011 for the EVAP Vent Shut Valve, the diagnostic should be very similar to what you would do with the stupid Honda scan tool.

Honda Service Bulletin 03-001
January 28, 2003

Applies To:
See VEHICLES AFFECTED MIL Comes On With DTC P1457: EVAP Bypass
Solenoid Valve Failure

SYMPTOM
The MIL is on, and DTC P1457 [leak detected in EVAP control system (EVAP control canister system)] is set.

PROBABLE CAUSE
The EVAP bypass solenoid valve can fail due to corrosion. The solenoid valve may get water inside. If the water contains road salt, the solenoid windings could corrode, causing the valve to fail. In a few rare instances, the corrosion could be severe enough to cause an internal short in the solenoid valve, which could damage the ECM/PCM. If this happens, both the bypass solenoid valve and the ECM/PCM would need to be replaced.
Vehicles driven in the Northeastern part of the U.S. are more likely to have this problem because of the salting of roads during the winter months. Vehicles driven where salt is not used on the roads are much less likely to have this problem.

VEHICLES AFFECTED
1998-02 Accord
1998-00 Civic
1998-01 CR-V
2000-02 Insight
1999-03 Odyssey
2003 Pilot
2000-03 S2000

CORRECTIVE ACTION
Test and, if necessary, replace the EVAP bypass solenoid valve. Replace the ECM/PCM if needed.

REPAIR PROCEDURE
1. Connect the PGM Tester to the 16P data link connector.

2. Turn the ignition switch to ON (II). Turn on the PGM Tester.

3. From the PROGRAM MENU screen, select HONDA SYSTEMS.

4. From the SYSTEM SELECT screen, select 1: PGM-FI.

5. From the TEST MODE MENU screen, select 6: INSPECTION.

6. From the INSPECTION MENU screen, select 2: EVAP TEST.

7. From the EVAP TEST MENU, select 1: SINGLE SOLENOIDS.

8. From the SINGLE SOLENOIDS MENU, activate the EVAP bypass solenoid valve. Listen for a click and feel for a light tap from the solenoid valve as you activate it.9. Replace the EVAP bypass solenoid valve (see section 11 of the appropriate service manual).

10. Test the new solenoid valve with the PGM Tester.11. Check the wire harness and the connectors for damage.12. Test the solenoid valve again with the PGM Tester.13. Replace the ECM/PCM (see section 11 of the appropriate service manual).

14. Use the PGM Tester to retest the solenoid valve.15. Insight only: Disconnect the PGM Tester, and return the vehicle to your customer.

16. All other affected models: Use the PGM Tester to run the EVAP system function test (see S/B 02-007, EVAP System Function Testing and Diagnostics With the PGM Tester).Honda Service Bulletin 01-011:
Attachment 20823
Attachment 20824

I agree about dropping the whole canister if the Vent Valve needs to be replaced. Do you think (when power is removed) the Vent Valve should immediately open to bleed the vaccum?