Resetting OBD errors on the fly


#1

We have two cars in the family, a 2000 Ford Ranger V6 and a 2003 Honda CRV which both throw OBD errors for non critical items about once every two months. After a few hundred miles the check engine light goes out, but while it’s on I don’t know if a truly critical “STOP NOW” error has occurred. I have a wireless OBD scanner in each car and I can read the error on a smart phone app. I’d like to just reset the code while driving, rather than wait for it to self correct, and I don’t want to go through the factory recommended ECU drive cycle relearning which involves a cold start and yada yada yada. What are the bad effects, if any, with resetting the OBD error codes and erasing the ECU drive parameters while trucking down the road at 70mph, ignoring the factory “PCM idle learn” procedure?


#2

As long as the Check Engine light doesn’t flash it’s not a “STOP NOW!” condition.

I don’t know why anyone would allow a Check Engine light to continually come on and not fix the problem. Especially when you have the means of pulling the codes.

Tester


#3

@‌CoffeeAddict

Please tell us what these codes are


#4

If you’re not going to fix anything anyway, just put black electrical tape over the CEL. Of course, we’ll be happy to help you in a few months when you post back that your engine is frozen solid, but you’ll have to tolerate our saying “we told you not to do that”.

Noncritical items often become critical items. But only if you ignore them.


#5

Just as it’s a bad idea to text while trucking down the road at 70mph it’s also a bad idea to futz around with your scanner link at 70mph. Not to mention that I don’t think the Honda will allow a code clear with the engine running. So wait until you are home to reset them.

The OBDII drive cycle is not a factory recommended procedure but a federally mandated one. Thank the government for this one.

If you have a check engine light and associated codes why not just fix them? There’s broken and there’s fixed. Simply clearing a code doesn’t fix anything.


#6

It’s kind of sad that money is spent on wireless, smart phones, downloaded apps, and so on and yet there is no inclination at all to do what should be done; fix the problem.

This reminds me of the poster on this forum a few years ago who was looking for info about his now magnified problem due to the CEL having been on for the last 2 or 3 years.
This poster also referenced “all of his friends have been driving around for years with their CELs on…”.


#7

@CoffeeAddict‌, don’t try to clear codes with the engine running. The clearing of codes basically resets ALL the monitors by function, so you would need to re-run the drive cycles regardless. But, attempting this while driving may damage a very expensive ECU. Why risk that?

Can you post the recurring codes? We may be able to help you fix them.


#8
"This reminds me of the poster on this forum a few years ago who was looking for info about his now magnified problem due to the CEL having been on for the last 2 or 3 years.This poster also referenced "all of his friends have been driving around for years with their CELs on...".

Yes, that was pretty extreme, but I think that the winner in the “how long can I ignore a problem” competition was a woman from Maine who wanted us to tell her what was wrong with her Suzuki (??) whose CEL had been lit up for 16 years!

Throughout my adult life, I have observed that people with problems of any kind manage to convince themselves that their problematic situation is the norm, and that everyone has the same problem. Just as “all of his friends” have–supposedly–been driving around with a lit-up CEL for years, people whose kids have been arrested multiple times will tell you that “all teenagers have police records”. (Trust me–As a HS counselor, I have encountered Denial Road many times with parents of jail-bird kids)

I guess that it is just human nature to try to pass off aberrations as being normal, in order to make yourself feel better about the situation–even if it does nothing to remediate the problem. Hey–who wants to deal with reality?

All of that being said, the only time that I ever had a lit-up CEL on any of my cars was on my '02 Outback, when the evap system’s purge valve went bad. I drove directly to the dealership, with no appointment, and I drove home less than 1 hour later after the free warranty-related repairs. Personally, I just can’t imagine ignoring a lit-up CEL for more than a few days, but then again, I also can’t imagine ignoring chest pains, as some people do…


#9

You guys can condemn me . . .

I’ve often cleared codes with the engine idling . . . in the workbay, and only after fixing the problem that triggered the code in the first place

But I’ve never cleared codes at 70mph


#10

There might be a danger of the ECU going off into the Twilight Zone if, for an instant, it loses all its learned operating parameters while it’s trying to operate and control the engine…

Talk about driving while distracted…


#11

Db, there’s nothing wrong with clearing the codes with the engine running… as long as it isn’t pulling you down the highway at 70mph.

It’s like reading a map… perfectly okay, but can be deadly or kill innocent people if you do it while driving. I recently saw some idiot trying to drive while talking on a cellphone and reading something he’d placed on his steering wheel. May he strike a bridge abutment… just hard enough to teach him a lesson.