Check engine light on...again...ECM issue.

Hello,

I have a '99 Accord Coupe, 4cyl that recently was in the shop for a bad
Bypass Colenoid Valve (BCV). The check engine light went off and
returned again three days later.

The mechanic told me if the light returns that it is most likely going
to be the ECM, which will be more costly than the BCV.

My question is this...how long can I run my car with a bad ECM? I am
currently low in funds and can not afford this replacement especially
since I did my timing belt package a couple weeks ago.

Thanks!

Jessica

 

Sounds like a simple EVAP problem. What was the actual alphanumeric code?

First off, other than the Check Engine light, what else is wrong with the
car's behavior? Is it starting and running fine?

Your mechanic may be feeding you a line here. "Failed ECM" is a common
diagnosis for mechanics who are stumped by a problem.

Honda ECMs are exeedingly reliable and almost never go bad unless flooded
or subject to electrical trauma.

How to check your ECM:
1) Insert key in ignition
2) Turn key to "II" (NOT to Start [III]) and leave it there
3) As key is turned to II, the Check Engine light will turn on
4) Two seconds later, CEL will turn off.

If the CEL does not come on, comes on and remains on for good, or stores an
error code that does not exist, then it is bad. Otherwise, it is not bad.

 

I agree with that in spades! In my experience, at least 90% of ECM
condemnations (other than those in flooded cars) are mistaken.

If for some odd reason you do need to replace the ECU because the engine is
running badly or drinking gas like crazy, wrecking yards are the best
source. You should be able to get a used one with a 30 day guarantee (if it
works 30 days, it should work forever) for less than $100 US.

Mike

 

Greetings,

The car is running fine. There are no weird noises, sounds, or
problems with starting or running the engine. I just came back from a
6 hour trip (when the CEL came back on) and it was fine for the entire
ride. I have driven it around town for the past couple days and it has
been perfect.

Today: I turned the key to "II" and the CEL came on, turned off (for
probably one second), and then came back on for good.

When I went to the auto parts store yesterday for a free diagnostic
test...the code read:

"P1457
Manufacturer Contrl.
Auxiliary emission
Controls"

The mechanic gave me a print-out of the initial CEL problem from
www.alldatapro.com when the bypass solenoid valve was repaired. The
code for the mechanic also said P1457. On the print out it says:

Failed part: EVAP Bypass Solenoid Valve
ECM/PCM

Then the print-out goes on to tell the repair procedure. Anyways, he
repaired the valve and the light turned off for a few days and now it's
back with the same error code. Since this code (P1457) has come up
twice, does it mean it's the ECM?

Thanks!

Jess

 

Incorrect.

Correct:
Evaporative Emissions (EVAP) Control System Leakage (EVAP Canister System)

This is as opposed to the fuel tank side of the system, which is error
P1456.

Maybe, maybe not. He has no way of knowing.

No, it means he didn't diagnose the problem properly. The code just means
an air leak in the sealed evap canister; it does NOT necessarily mean the
bypass solenoid is bad.

He needs to close all the solenoids, then apply vacuum to the tank and see
if it holds vacuum or not.

Trust me, the ECM is NOT the problem here. Maybe you need a better
mechanic.

 

Actually, it's a bit more complex than that, but a good shop manual will
have the complete testing procedure for the evap system.

 

Ok. I will have to shop around for a better mechanic.

Is the car safe to drive? I have been using it all week without issue.

j.

 

Sure will. Current guy has a point on his head.

Sure is. EVAP problems are purely and totally governmental in nature.

Of course you have. Your problem is a regulatory one, not a functional one.

 

make that two. the single point is on the end of his tail.

 

I'm back. Ok, I have been using the car now for a couple weeks with no
issue. When I find a new mechanic, do I simply tell him that I need
them to check my tank (I presume that it's the gas tank) for leaks?
How much should this roughly cost? If they do find a leak, what will
need to be replaced...the tank?

Unfortunately, I just moved to VA and I will eventually have to
register my car which means a state inspection test. I won't be able
to pass if the CEL is on. Is there a way to override the system, even
if it is only temporary?

j.

 

It's not. Read the earlier posts in this thread.

Your error code denotes the charcoal canister in the engine compartment.

There are four or five things stuck into the sides of the charcoal
canister. All of them can stick shut, stick open, perforate or otherwise
fail to proceed as intended. There are set procedures for testing all
those parts. The factory manual gives them, as does Mitchell and other
trade publications. It is not rocket science, as the cliche goes.

You need to find a mechanic who has more than one brain cell. This
genius will test the canister according to how the parts of it work and
will thus uncover the defecive part on it.

Failing all that, you can acquire a entire used canister system from a
local wreckers for cheap, and just throw it in there. It just might fix
the problem.

Another possible solution involves going in to your local dealer. He
will be able to check for TSBs on the problem, and will have (hopefully)
been a regular reader of Honda Service News, which covers little
problems that are not worth issuing TSBs for.

Nope. Not any more.