Gday!

So my sister is the proud owner of a 2014 TL SH. She purchased the car back in October. Since then the following has happened.

Whenever the temperature gets down to approx -17C (1 Fahrenheit?) The car is hard to start and then runs quite rough. Sometimes the rough running will clear up on its own. Video attached for your amusement
Also there are abt 4 or 5 dash warning lights that come on. Engine, Traction Control, ABS etc etc.
The other day she drove approx 200km (125miles) and the car used a half tank of fuel. Ran awful the whole time.
Sometimes after 3 starts or so it will clear up on its own.
If the ambient temp gets above -17C then the problem seems to clear up on its own. Runs well, no warning lights left on.
Anyone have any idea on what could cause this?

Note: She used premium fuel from October to December and switched to Regular at that point. Fuel doesn't seem to make much of a difference.

Thank you for any help!

 

Well first off I would get the codes scanned and it will give you an idea of whats wrong.

But more importantly don't let her put regular in it!!! Its running rough, its got regular in it and you don't see those things as being related??

The owners manual is specific that with the 3.7 motor prolonged use of regular can lead to engine damage.

 

She had it checked for codes....none came up, Like I said the problem disappears when the temp is above -17!
Yes obviously I can see those two things as related..fuel type and rough running. BUT as stated in my post this thing runs like a dream when its warm out. Cannot be purely fuel related as far as i can figure

 

Definitely sounds like crap. So there are no codes whatsoever? If the check engine light is on there's got to be codes. Although I have had times where a bunch of lights come on at once where the problem has been battery related. The car is pretty sensitive to voltage. If it's lower than it needs it freaks out a bit.

I'd clear the ECU first. Pull the negative battery cable for about 5 minutes then reattach. Second, I'd check the voltage at the battery terminals while running. It should be between 13.5V - 14.2V. Third, especially based on the fuel usage, I'd consider cleaning or replacing sensors. Specifically the MAF and upstream O2/fuel ratio sensor. A bad upstream sensor can cause poor fuel economy and a crappy running engine. The MAF sensor can be cleaned with some sensor cleaner from CRC. The O2 sensors usually require replacement, which can be a bit spendy. I'd only consider that as a last option.

 

Yeah the lights all go out when it warms up. Took it to the shop and they say no codes showing up.
She was told a bad battery could cause the lights to come on so changed the battery.

 

So you're still seeing the issues with the new battery?

 

Yes.
Just got an update; tire sensors are intermittent when its cold outside, SHAWD, Hill Assist and Vehicle Stabilization lights come on as well.
Computer issue?
Strange that it is temperature dependant

 

SH-AWD and a lot of the associated electronics are VERY sensitive to voltage during startup. Also the SH-AWD system uses electromagnetic clutches; improper voltage/current = big issues.

the lights clearing and running better can be related to the O2 sensor or another system that clears codes after 3 starts and drive cycles. O2 sensor reading very lean or rich can cause drivability issues.

Honestly, start by checking all ground points for corrosion and make sure your battery tests good. Modern Honda/Acura cars from 2000+ love to kill batteries within 2 years.

Get a good AGM battery and you'll notice a lot of issues disappear and the battery will last at least 3-4 years.

VSA/stability/hill start/abs all rely on the wheel speed sensors. IF voltage is low it can trigger all of those systems due to a faulty reading.

Did you try to rule out any sort of water in the fuel? With it being -17 that makes me think either water in fuel + low battery for the whole situation. Also gas does go bad over time and does accumulate moisture no matter what you do since it has at least 10% ethanol that loves to bind to water

 

That sounds awful!

 

I've got a FWD, but I've run into really really strange car behavior when my battery was low. Really strange like random lights (cel + vsa +stability ) coming on, nav screen showing check emissions system messages, nav showing check vehicle stability system, etc. Running rough when it starts up, to making weird noises when starting up. If it's neg17 where you're at, I would check that battery like the others have suggested.

 

[QUOTE=shlickster;16358682]Gday!

So my sister is the proud owner of a 2014 TL SH. She purchased the car back in October. Since then the following has happened.

Whenever the temperature gets down to approx -17C (1 Fahrenheit?) The car is hard to start and then runs quite rough. Sometimes the rough running will clear up on its own. Video attached for your amusement
Also there are abt 4 or 5 dash warning lights that come on. Engine, Traction Control, ABS etc etc.
The other day she drove approx 200km (125miles) and the car used a half tank of fuel. Ran awful the whole time.
Sometimes after 3 starts or so it will clear up on its own.
If the ambient temp gets above -17C then the problem seems to clear up on its own. Runs well, no warning lights left on.
Anyone have any idea on what could cause this?

Note: She used premium fuel from October to December and switched to Regular at that point. Fuel doesn't seem to make much of a difference.

Thank you for any help![/QUOTE
Find any solutions yet? If it system wide it could be the:

• ECU may need to be updated or replaced.
• NEVER USE NON-PREMIUM FUEL. EVER. EVEN IF YOU DONT NOTICE RIGHT AWAY.
• WHAT TYPE OF OIL ARE YOU USING?