Howdy.

Got a certified pre-owned 2020 with 38k miles on it two weeks ago. Nice car, but after some cooler weather (specifically, overnight-rain), had some strange issues. The digital section of the dash got all scrambled for a little bit, but straightened itself out within the day. But I had 4 warning lights come on all at once a little later: check engine, VSA, tire pressure (which blinked before going solid), and power steering (which came on like a minute after).

That surprised me since nothing seemed wrong whatsoever despite being a rather alarming sight (no chime either), so I looked it up and got like 100 different conflicting answers where people were like "oh yeah, those 4 lights being on is specifically [x] for sure" so I guess it's just a general indicator, but I don't know how serious it's meant to be.

Since it happened after some rain, I trusted someone saying that it was just some weird electrical issue that could be resolved by disconnecting the battery for a little bit. Tried that, and it worked for a day, then it came back. Tried again, disconnected a little longer, and it worked a little longer.

Took it to get an OBD scan, and got P0302 (cylinder 2 misfire), which surprised me as well since everything felt/sounded fine and I thought typically they just flash the CEL for that instead of having 4 solid lights. Also got a U0401-68 (ECM failure) which I can find little info about. Swapped coils with cylinder 3, and the code didn't change, so I got a new spark plug. Seemed fine, then a day later, they're back. Haven't had a chance to see if I'm still getting P0302.

Anyone have any ideas? Might just be coping that this is something minor I can tweak myself and not something I gotta gamble if the CPO will cover (I imagine either fuel injector stuff, or carbon buildup stuff). And what are my risks for holding off on touching this for a few days?

 

How old is the battery? How do the electrical ground points (I know, there's a lot of them) look?

 

Just had a similar experience with my 2017. Very cold weather and four dashboard lights on together: tire pressure, check engine, power steering, and traction control. These lights have been on for the last three days and the car is still running fine so far. Curious if you found a solution?

 

Display failure: https://www.fitfreak.net/forums/3rd-...y-failure.html

Wonder if your injectors are fouling. Honda has not fixed the carbon fouling problem with this engine. We've seen reports of severe carbon fouling with as little as 10K miles. Search this subforum for details.

I've wondered if this was a reason contributing to dropping the car in the US market after 2020.

If this is a "certified" vehicle, you might want to go back to the folks who did the "certifying."

 

Okay, a bit more educated (on my part) answer: A single error can cause multiple warning lights. The car's various modules (ABS/VSA brake unit, engine control module, electric power steering, forward radar unit, camera unit and so-on) all communicate with each other and seem to have blanket module-readiness flags. This is important because the modules all work together to achieve the more advanced driver assistance features. Not just lane keeping and collision mitigation, but simpler things like traction control.

We experienced one with our 2020 EX. We got a flat tire while touring the Blue Ridge parkway. Being far from home and slightly middle-of-nowhere, we had some trouble getting the right size replacement tire to drive home on. The tire shop gave us a low-profile tire that was about an inch smaller in overall diameter than the rest of the tires, making that tire spin significantly faster than the rest. The ABS/VSA unit pays close attention to wheel speeds as part of monitoring vehicle dynamics and traction, so it freaked out. IIRC, it threw VSA and traction control lights/warnings. Seeing that the brake unit wasn't ready, the LKAS and CMBS threw warnings and disabled themselves. I guess the EPS gets steering-center information from the VSA unit or something, so it threw a warning light. The ECM heard the ruckus and decided to dive in just for funsies.

Point being, the gauge cluster makes lots of noise, but it's probably one root cause. Take the car to a shop or auto parts store that has a scan tool, see what the error code is. The infotainment unit may even be able to tell you what the error is if you figure out how to put it in service mode.

 

@bobski Good to know about service mode for the touchscreen. Looks like that does not cover ODB-II diagnostics, however. Should probably take it to an autoparts place and get a readout.

@bargainguy I was not clear enough about my experience. I was referring to the 4 warning lights on simultaneously and not the "digital section of the dash got all scrambled" part of @mushroom 's post. I will search for injector fouling, thanks for the recommendation.

 

Just charged the battery and all the warning lights went off! Looked at the receipt for my battery and it's 4 and half years old. Hopefully a new battery is all I need.

 

You should upgrade to a 51r Battery.

 

This. They're slightly cheaper, easier to find, and have roughly 50% more capacity. The only modification is clipping a corner off the battery tray, which might not even be necessary on your 2017 tray. There's several forum threads discussing it and even a few youtube videos.

 

Thanks for the recommendation @Chitown Fit

Just ordered a new battery tray online for $20 before seeing your comment @bobski about maybe not needing it. So I rushed out to the garage to have a look and I do have the US 151R tray so I can still feel like it was $20 well spent. This will be my 4th battery in this car and I did notice that its small battery was more expensive and harder to find than more common sizes, just didn't realize how easy it was to use a bigger, more common size. Kind of like the stock tires traction on wet roads was terrible until I switched to slightly wider tires based on recommendations here.

 

Tires are a whole 'nother thread. More tire will get you more traction, all else being equal. However, the range of "all else" is quite wide - tire materials and construction can make a huge difference. I would take a narrow "high performance" tire over a 50% wider "touring" tire any day. The UTQG markings will get you started, but only cover tire wear (the number, higher lasts longer), wet braking traction (first letter, AA is best, then A, B, C), and heat generation (A, B, C). Tire Rack has a customer survey system that covers much more - it's a good resource even if you're buying tires elsewhere.

 

For those that have the 151r Battery tray that need the 51r Battery tray, go to your local Honda Dealer.

Here's the 51r Battery tray Honda part number,

31521-T5A-000

 

Or get it on ebay for 1/3 the price.

 

Hopefully you won't get the 151r Battery Tray by mistake or on purpose.

If it's the wrong Battery Tray then you have to go through the hassle of returning the Tray and getting your money back.

At least at the Honda Dealer you can check if the Battery Tray will fit the 51r Battery.

If not you can re-order right at the Honda Dealer.

 

On my new-to-me 2017 Honda Fit EX 6-speed with ~117,000 miles, I got the same mix of warning lights three or four times a month ago. My FOXWELL NT510 Elite code reader with Honda software said Cylinder Misfire on 2 and 3 and Random Misfire. After the second or third round of warning lights, I decided to check spark plug torque and none of the plugs were properly snugged (CarFax said it had received new plugs and injector flush at the local Honda dealership three months ago). #2 took almost a full turn to reach 16 foot lbs; #3 a half turn; #'s1&4 about a quarter turn. Also, battery (151R from 2024) posts and terminals were a bit gunky, so I ran an old school post and terminal cleaner wire brush on them.

I then took a chance and called the dealship listed as doing all of the maintenance for the previous owner on the CarFax, and the Service Advisor recognized the car when I gave him the VIN/previous owner and said she declined the work and traded it in when advised it needed new injectors.

Although I bought one of the Honda fuel injector replacement kits (great deal!) from https://honda.oempartsonline.com/, for now, I'm running a bottle of Techron through it. I have only gotten the lights once in the last 500 miles/30 days (I don't drive a lot) and noticed no changes in driveability when the lights were on before I reset them.

Totally anecdotal, but I've never gotten the warning lights when starting the car with the headlights set to "OFF"...each time was with the lights set to "Auto".

ScottK