My car is throwing codes - just a quick post to see if anyone has an ideas what this could be? 5,800 miles, just got back from a new clutch and the cats were taken off the car to do the clutch, of course.

CEL pops on 25 miles later. I have a basic OBD2 scanner but its not Aston Specific so it may not be reading correctly as I can only program it for 'Euro Cars" rather than brand specific.

Error codes are "Intermittent Misfire" and across all cylinders. I cleared the codes, ran it another 25 miles and they returned. A trip to the dealer may be in order, but thought perhaps Irish or someone else has run across this before?

TIA

 

Check out the attachment to post #46, on the link below. It sounds like you may be having problems associated with learning "Misfire corrections" - just a guess on my part.
Do you know if the dealer performed the road test before returning the car to you?

https://www.6speedonline.com/forums/...talling-4.html

 

DonL is right.
If a new clutch was installed, then more than likely a new flywheel was installed. A misfire correction test drive maybe be needed to relearn the new flywheel.

 

Yes. A new flywheel was installed.

I read Irish's post and am trying to make sense of it all. Sounds like it requires the dealer tech to reset it all from what I'm able to take away from the conversation? Not something I can do myself?

Fascinating concept by the way. Would would have thought?

 

^^^^ you can do it yourself.

 

I can't seem to find Irish's post. But basically you only need the dealer to reset or clear the values, not to set them.
1. Car needs to be at operating temp.
2. Drive car safely up to 70mph, with the a/c off, in "D"' or manual allowing car to reach 6th gear.
3. Once 70mph is reached, allow car to coast to 30mph, without hitting the brakes.
4. Repeat again up to 70mph coasting back down to 30mph, without hitting the brakes.
If you hit the brakes anywhere in here. That process won't count and you will need to do it again.
The process needs to be done twice correctly to count.
You won't know if there set unless the dealer checks.

 

That's pretty crazy.... so I take my OBD2 code reader, then clear the codes - warm up the engine and follow the procedure from AMFIXER and that should index whatever needs to be done to get it to stop throwing a CEL?

I have to say, never in a hundred years would I have thought a flywheel replacement would be tied to a Check Engine Light and throw an emission service code. Cars today truly are computers on four wheels. Somedays I miss my old 1963 Corvette Split Window Coupe that was so simple to work on any shadetree Joe could do it.

Great tips. I'll give it a shot and report back. Thanks.

 

Update to this thread.

I cleared the codes with my OBD 2 Acton-brand scanner and tried the indexing procedure, it didn't work.

Yesterday I went to AM of Washington and the Tim, the Tech who installed my new clutch put it right on his scanner and told me the reason was it needed a full memory clear, my little cheapie scanner wasn't 'deep-erasing' the codes and clearing only the most recent ones. So he did a full clear and sent me out on the Dulles Toll Road to do the 70 mph to 30 mph coast down, and told me to do it at least four times.

I have to tell ya, that is more challenging than you think to pull that off in rush hour traffic. To get up to 72 mph and then coast down to 28 mph and not touch the brakes while in traffic and having to to it 2x in a row could be a new sporting event. You have to start in the fast lane and make your way over to the shoulder with your hazards on while coasting and not touching the brakes. I'm sure people thought I was nuts....

Seemed to have done the trick though. No CEL after 50 miles of driving.

 

you did that during rush hour up here??? i can't get above 40 for most of my commute!

i'm going to try to do this myself this weekend. there's a toll road between Dulles and Leesburg that's been pretty dead each time i've been on it on a Sunday morning. i'll be heading out that way.

 

If you replaced the clutch and they "DID CLEAR" the misfire corrects, this is done with a dealer scan tool...you will get a misfire 100%.. On pre 2009 models you can remove the battery terminals and touch them together for 20 seconds, this will do a complete clear..then do the road test relearn procedure..the flywheel is ur crank position sensor pick-up..so vehicle thinks it's misfiring just because the flywheel was replaced or even moved.

If you did this at the dealer, I'd through the car back at them..this is a known thing for AM techs when doing a clutch..time for this is always taken into account when clutchs are replaced, so you shouldn't have to pay anything providing it's the misfire correction issue.

Untill they are cleared..you can road test and do as many relearns as you want...engine light will always come back

When they are cleared, the relearn is VERY important..untill relearned you will NOT have misfire detection..you can disconnect a spark plug and no mifire will even be flagged for a DTC

 

Right...How does a dealer let a car go like this? They should have known better.

 

My tech at AM of Washington who did the job told me he did do the procedure, but didn't know why it didnt' 'take'.

Meh...no biggie, nothing damaged or hurt on the car. Just took another trip over there to clear the codes, everyone makes mistakes and he's a good guy - not going to take him to task over it. Having survived a terminal cancer and still here to tell the tale, I don't sweat the small stuff ya know? It's all good.

 

Awesome, glad it got sorted out..always true, we're only human, mistakes do happen, makes things better when it's easily solved..I know the boyz in Wash, some good tech's..

 

Is the same clear all and road relearn procedure needed on a Manual gearbox equipped car after a clutch/flywheel change?

 

Yes the process is the same, just need to make sure the car is in 6th gear.