Help...Check Engine Light

Aside from all the car issues you experienced, this can be troubling if ice kicks in while car is turned off. I would most probably be charging the car in an enclosed garage and wouldn't want the ice on while the garage doors are shut.

 

Some questions to try to understand exactly what happened.
1 Was the car off? Not on Accessory?
2 Have you had the all the updates applied? especially the 18-097?
3 Are you sure the engine was running? There are two fans under the hood and in an enclosed garage can sound loud.
Next time try gingerly feeling the exhaust manifold in rear top of engine to see if it’s warm/hot. That’s will tell you if the engine ran.

It’s my understanding (not documented) that the engine will not run with the car parked and off so as not to unexpected fill a garage with CO. If yours really did come on when off and parked I wouldn’t garage it in my house until I took it to the dealer for service.
Please let us know what happens.

 

My gut tells me its your battery charger sensor. My clarity would not properly charge at one local station yet worked good at other stations. It would Charge a few minutes and then shut off. Took it to the dealer and had them check it with the check engine light on. They said it was a problem with the the battery charger sensor. I had previously had all of the service bulletins installed. It nows works great at that level 2 station.

 

I do not think it is possible for Clarity (at least a properly working one) to start the gas engine when the car is off. (Can Clarity run the engine for climate pre-condition? I did not think so). If your gas engine started while the car is off, I would have the dealer look at your Clarity ASAP (would be dangerous in a garage as mentioned above).

Review the accessory mode that KentuckyKen mentioned. Most EVs have one or more accessory or service modes that come on with various combinations of start button presses. It is easy to unintentionally get into one of those modes when stopping and restarting when there is an error indication.

Another possibility (although neal akins, charge sensor is probably right), is that a 12V battery problem can cause any number of EV glitches. For example, when intentionally disconnecting the 12V ground connection (10mm nut) for a short time to reset the car, there are any number of errors following the next start, which if the car is okay, all go away at the beginning of the next drive.

Very few Claritys are really "broken" and even fewer are "lemon broken". If practical, a dealer visit sounds warranted. Otherwise, there are any number of glitches that just reset and all is fine. A 12V battery problem (bad 12V battery (e.g. from a long sit on a dealer lot without a 12V battery charge, a known problem), or bad 12V connection) would likely cause repeated errors over time.

 

No one has posted yet as to whether the 2019s have all the updates installed. And the 18-097 SB to fix charging problems is not installed by dealers until you tell them you are having a charging problem.

Unfortunately when it comes to dealers and Honda regarding the Clarity you have to assume the worst since it’s almost universal that they will not be well versed on the workings of the Clarity. I suggest you make the dealer run it through their i-HDS (hope I got that acronym right) tool and give you a print out that shows the updates are installed. Otherwise I would not believe them based on experiences shared on this forum. And while they’ve got it hooked up to the i-HDS, ask them to run a Battery Capacity Test so you can verify the health of your 17kW battery.

This is really the only way you can know for certain.

And @sniwallof’s comments on a bad or low voltage 12 v battery causing problems is spot on as is his other observations. And as mentioned, some have had “gremlins” chased away by a hard reset (disconnecting 12v battery for a few minutes).

 

Mine did this once when I hadn't had the car too long (maybe a month). It was in the same time frame that the car threw a fit with the dash warning lights a couple of times. I believed the loud blowing sound was from fans/pumps in the car, not the ICE, but it was LOUD. The check engine light did come on and then reset after a couple of drives. It has not happened again in 10 months of ownership, and I never had any of the Service Bulletins applied. I figured I'd wait until the oil change and let Honda do them then. I do suspect the charging SB might take care of it, but I don't think it is a real problem, albeit, I'll agree it will scare you pretty good when it happens...

 

I would be interested in any follow up information you get from the dealer on this, and I would encourage you to take it in and have them tell you what they see in the history data. The thing that I am most concerned about is the possibility of the engine starting when the car is off. I hope that the noise you observed was not the ICE starting, as that could have truly catastrophic consequences. People have literally died because they didn't realize that they left their engine running in an enclosed space. https://www.chicagotribune.com/suburbs/lake-county-news-sun/news/ct-keyless-ignition-risk-met-20150618-story.html

 

I'm pretty sure with mine that it wasn't the ICE making the loud noise, but in truth, the ICE could have probably been running and you wouldn't have been able to hear it over the other sound the car was making unless the RPM was significantly above idle...

 

Check your wiring / voltage stability from the house.
If your power is "dirty" or noisy with glitches or spikes, the charger could send that to the car causing an intermittent issue...
Also, if you had a brownout, that may affect the charge cycling.

 

Inverter cooling fans can be quite loud at times while charging.

The obvious answer in my opinion, if warning lights and gremlins continues/repeats, or something is still not normal, is to take it to dealer. Nobody here will have a clue why such things are happening.

Understand these cars do make a substantial amount of varying noises at times when charging. Sometimes they are silent. Sometimes quite loud. Leaf blower is probably an accurate statement when inverter fans kick in, though I feel they are much quieter than most leaf blowers. Get used to that. There is no need to react to it in any way. Given time, it finishes whatever it’s doing and moves on with its life.

If you really think engine is running, hand behind exhaust pipe will confirm. I bet $100 the engine was NOT running, just electric cooling fans which are sometimes required during charging process. Don’t interrupt them.

 

Wow. I am very glad you posted that. My car has always been totally silent while charging, and I would probably have freaked out if it had been noisy after all this time. Or, I should say, WHEN it is noisy after all this time. The temperature here as been cool to cold since I began to charge at L2, so I expect that's why there has been no need to run any kind of cooling fan. Thanks for the heads up.

 

Mine is usually silent too. Sometimes at random whenevers things spool up for a bit. Then they spool down. I suspect those in warm climates hear more racket than those charging in the cold. I never know what kind of strange gremlin I might hear when I walk in the garage. Usually nothing. Occasionally something.

 

The rapid succession of failure messages... was it brake system failure, ACC failure, LKS failure, Power steering failure, etc? This sounds like the bug that one of the SB fixes. I've had this a couple of times (also early in ownership) and haven't seen it again in about 8 months. I plan to let Honda apply all the SBs due when I take it in for first oil change. I don't remember all the failure messages with the loud fans after unplugging at near 100% charge incident, though. But it has been a while, so I am not crystal clear on that. I do remember it tripped the check engine light for a drive or two.

 

For future reference: If you ever get a check engine light, and don't have an OBD scanner, take your vehicle to any AutoZone, O'Reilly's, or pretty much any auto parts store. They will read the error code for free.
Though this definitely sounds like the SB 18-079 charging/error message issue, if you ever get another mysterious EV problem, the first place to check is the 12V lead acid battery. Recharging or resetting the lead acid fixes a multitude of problems for LEAF, Tesla, and Volt owners.