Codes cleared after being read?

Daughter's 02 Civic CEL came on three times in 10 days. On each occurrence, the car immediately went to idle, but after being turned off and restarted, the car ran fine with no CEL. After the third time, she took it to an independent garage. The mechanic told her the code indicated an ECM (ECU, computer) problem and she needed to take it to a Nissan dealer. Her appointment with Nissan is tomorrow.

The question is: When the codes were read, would they have been reset? Or will the fault code still be there? No need for her to pay $85 to Nissan if there are no codes to read...

Thanks.

Reply to
Williams
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Williams wrote in news:i0wko.74740$ snipped-for-privacy@newsfe15.iad:

You're not interested at all in *fixing* the problem causing it?

Reply to
chuckcar

Williams wrote in news:i0wko.74740$sL7.35953 @newsfe15.iad:

I hope you meant to say "Honda", not "Nissan".

Reading the codes and clearing them are separate operations. Many techs seem to clear them as a matter of course, which is fine so long as somebody bothers to record what they were.

If the MIL is currently off, the codes are probably gone.

But some codes are two-trip logic, and you have a one-trip "preliminary" code that's set before the MIL comes on. Don't know if this will be applicable in this particular situation.

Word to the wise: ALWAYS ask the tech or garage to WRITE DOWN any codes they find and give them to you. And to write down the actual alphanumeric codes itself (e.g.:P0420), NOT the text description. I'm a bit surprised how many techs simply clear codes without recording them anywhere.

Reply to
Tegger

Absolutely I'm interested in *fixing* the problem. However, the old adage applies: You can't fix it if it ain't broke. So if there are no codes to read, what would the shop fix? That was the purpose of this post -- to ascertain if the codes were reset when read by the independent garage. If there are no codes, then she needs to wait for the problem to recur before taking it in for diagnosis.

Any mechanics out there who know the answer? Thanks again.

Reply to
Williams

Oops -- meant to say Sentra, not Civic. Her older sister had the Civic.

Reply to
Williams

"Williams" wrote in news:uaxko.66260$ snipped-for-privacy@newsfe24.iad:

Everything else I said is still true.

Reply to
Tegger

"Williams" wrote in news:q5xko.66259$ snipped-for-privacy@newsfe24.iad:

I'm not a pro, but I thought I had a pretty good answer in my previous post

And you're right. If stored codes have been erased and not recorded, the dealer will have less information to work with than they would have had if the old codes had at least been written down before being cleared.

But the dealer /can/ look at other things besides the code itself:

1) the large amount of other information that Nissan's diagnostic tool can display, separately from any stored OBD-II codes, and 2) TSBs and other documents issued by Nissan that deal with the reported symptoms.

The foregoing is available to independent garages as well as dealers, but most garages seem not to avail themselves of it, for some very odd reason.

Reply to
Tegger

Thanks for the advice. The independent garage is just across the street from the Nissan dealer. So perhaps she can check with the original mechanic to see what the codes were and whether or not he cleared them.

Reply to
Williams

If the codes are gone and their is a true problem the codes will probably come back.

Most shops tell me they can't fix what isn't broken. They usually wait until the problem occurs and then try to solve it.

It could also be possible your ECM may need to be flashed, and that shop can't do it.

Reply to
m6onz5a

"Williams" wrote in news:q5xko.66259$ snipped-for-privacy@newsfe24.iad:

If you want to fix the problem, You don't clear the codes, so you *know* what the code was. Reading the code will tell you that. You don't destroy the contents of a computers memory by reading it either. Exactly the same thing.

Reply to
chuckcar

It is a separate step to reset the codes after reading them. If the light is out, your shop reset the codes. So, yes, you will have to wait until they recur. Next time, either tell them not to reset it or make sure they write down everything that comes out when they read it.

Since this "Civic" is apparently not a Civic, but some sort of Nissan, you might be interested to know there is still a procedure on all Nissans to make the system blink out the codes on the CEL light. It involves no tools, simply a stop watch and a sequence of pressing and releasing the accelerator pedal a predetermined number of times within a time limit.

Reply to
E. Meyer

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