ECM code being thrown due to altitude

[GoSlo]

A friend of mine just bought a 2018 TriGlide and now both times he's ridden it up into the mountains, it's throwing an ECM code. He talked to one dealership and they said it is a known problem with altitude and the ECM. The trike is set so lean that the rear cylinder isn't running right (?). Not positive on all the particulars, but he keeps getting the same code show up. They said they're pretty sure he'd be fine to just ride it, but he's worried about getting stuck up in the mountains and needing it towed if it stops running.

Has anyone else heard about or experienced this problem?

Side note: I bought my new 2018 the same week from the same dealership and have not had the problem....yet.

[GoSlo]

Forgot to say this about the ECM code. Here in the Denver area, we're about 5,000 - 6,000 feet in elevation and it doesn't throw the codes in town. When he gets above 7,000 feet or so, that's when it happens.

[Jack Klarich]

Nah, I don't buy it

If that were true ALL Harleys shipped from the factory would have the wrong fuel maps loaded in the ECM

Find another dealer JMO

[MDO]

A friend of mine just bought a 2018 TriGlide and now both times he's ridden it up into the mountains, it's throwing an ECM code. He talked to one dealership and they said it is a known problem with altitude and the ECM. The trike is set so lean that the rear cylinder isn't running right (?). Not positive on all the particulars, but he keeps getting the same code show up. They said they're pretty sure he'd be fine to just ride it, but he's worried about getting stuck up in the mountains and needing it towed if it stops running.

Has anyone else heard about or experienced this problem?

Side note: I bought my new 2018 the same week from the same dealership and have not had the problem....yet.

I have no idea what your talking about with the rear cylinder being lean & not running.

It would help if you mentioned what trouble code it is throwing.

Help us help you.

[GoSlo]

I have no idea what your talking about with the rear cylinder being lean & not running.

It would help if you mentioned what trouble code it is throwing.

Help us help you.

I don't know any more than what I've written. He doesn't know how to get the actual code, so all he can see is ECM Y. We know there's a way to do it, we just don't know what the steps are. Maybe if someone can explain that part, then I can post the actual code.

Thanks again....

[GoSlo]

He figured out how to get the actual code and it says this:

ECM Y

P0152

Rear oxygen sensor high / engine rich

Hope this helps.

[FuzzyWuzHe]

I don't know any more than what I've written. He doesn't know how to get the actual code, so all he can see is ECM Y. We know there's a way to do it, we just don't know what the steps are. Maybe if someone can explain that part, then I can post the actual code.

Thanks again....

It's in the owners manual I think ... but, basically you hold the trip button down while turning the key on

[Jack Klarich]

He figured out how to get the actual code and it says this:

ECM Y

P0152

Rear oxygen sensor high / engine rich

Hope this helps.

That would be TOO much fuel causing that code

The dealer needs to hook it up to the digital technician scanner again to see why it is throwing too much fuel

Or the rear cylinder is not firing

Has this trike any modifications or is it stock?

[FuzzyWuzHe]

That's what I was getting when the O2 sensor clogged ... is there soot in the pipes?

[Jack Klarich]

That's what I was getting when the O2 sensor clogged ... is there soot in the pipes?

I bet there is raw gas smell in the muffler

The ECM should compensate for the altitude unless it has been monkeyed with by the dealer already?

[MDF48]

GoSl said in the original post "A friend of mine just bought a 2018 TriGlide and now both times he's ridden it up into the mountains, it's throwing an ECM code. He talked to one dealership and they said it is a known problem with altitude and the ECM." So, he talked to a dealer, but has the bike actually been carried to the dealer? It definitely needs to be seen by the dealer.

[Jack Klarich]

GoSl said in the original post "A friend of mine just bought a 2018 TriGlide and now both times he's ridden it up into the mountains, it's throwing an ECM code. He talked to one dealership and they said it is a known problem with altitude and the ECM." So, he talked to a dealer, but has the bike actually been carried to the dealer? It definitely needs to be seen by the dealer.

Good call

I am wondering if this trike has any factory add ons like maybe a tuner with the wrong map?

[ultrafxr]

I call BS on this being a known problem. If a dealer tech did troubleshooting on the bike and said this he's full of it. I just got back from the Deadwood 3 Wheel Rally and afterward we went to Cody and then down to Colorado. I rode to the top of Pike's Peak and never got a code nor any runability problem. Something is malfunctioning or like others have said it must not be stock and has a bad tune or needs a tune.

[GoSlo]

Lots of posts to reply to, so hopefully I get them all answered.

The trike is stock, no mods at all.

he has taken it in to a dealer to have it looked at, twice now. They clear the code and it comes back again once he gets above around 7,000 feet.

He was told this is a known problem on SOME M8's, but not all. I have a brand new 2018 TriGlide, and have not had the problem.

He's bringing it in again tomorrow, but I figured I'd see if anyone else has this problem or had heard about it.

[MDF48]

Thanks for clearing that up. So it is the factory stock tune and not a "tuner" file. After the 3rd trip to the dealer, if it still does it I would at least call a couple of other HD dealers service department and see if they have ever seen this problem and code. Keep us posted.

[DK Custom Products]

Lots of posts to reply to, so hopefully I get them all answered.

The trike is stock, no mods at all.

he has taken it in to a dealer to have it looked at, twice now. They clear the code and it comes back again once he gets above around 7,000 feet.

He was told this is a known problem on SOME M8's, but not all. I have a brand new 2018 TriGlide, and have not had the problem.

He's bringing it in again tomorrow, but I figured I'd see if anyone else has this problem or had heard about it.

I've not heard of it.

I would be hesitant to take it back to the same dealer a 3rd time...they had two chances to fix it already.

Best advice is for your bud to call around and see if any other dealers have heard of this known problem with some M8's. If one of them has, next question is, do they know how to fix it?

Kevin

[GoSlo]

Like many suggested, it's the O2 sensor that's causing the problem, much like the 2012 bikes that were sold here at altitude. In 2012 a lot of the bikes experienced pinging when riding in the mountains. Harley came out with a new download for altitude to stop the pinging. I had a 2012 Limited and it pinged like crazy until they got it fixed. Seems as though that's what they're going to do now as well.

He called two other dealerships and they've all seen the same problem. Not on all M8 bikes/trikes, just some. So now he has to wait for Harley to send back a new file to download into the ECM.

Thanks to all that offered help/ideas/suggestions!

[MDF48]

GoSlo said "Like many suggested, it's the O2 sensor that's causing the problem"

Glad your friend is getting some help finally. Just one question, is it the O2 sensor that is causing the problem or is it the tune? Maybe a combination of both? Did they replace the rear O2 sensor? Maybe they can get him fixed up finally without all the trips to the shop. Good luck.

[Teufelhunde]

A friend of mine just bought a 2018 TriGlide and now both times he's ridden it up into the mountains, it's throwing an ECM code. He talked to one dealership and they said it is a known problem with altitude and the ECM. The trike is set so lean that the rear cylinder isn't running right (?). Not positive on all the particulars, but he keeps getting the same code show up. They said they're pretty sure he'd be fine to just ride it, but he's worried about getting stuck up in the mountains and needing it towed if it stops running.

Has anyone else heard about or experienced this problem?

Side note: I bought my new 2018 the same week from the same dealership and have not had the problem....yet.

I will call BS. Find another dealer. With the bike set to run lean, if anything, as altitude increases, it should run better due to a richer mixture with thinner air.......

YMMV

Lon

[GoSlo]

This is an update on my friends 2018 TriGlide that was throwing codes when he went up in altitude, usually above 7,000'. It stopped doing it!! He's still waiting for the new download from H-D, but for now it's not throwing anymore codes. Over time the codes were thrown less and less and the light stayed on for less and less time the more times it happened. No one seems to know why except that maybe it's "learning" better? Anyway, wanted to let you know what's been going on with this problem. I still have not had any codes thrown at altitude on my M8, so that's a good thing.