First thing to be aware of it that it is “normal” for a Subaru to disable most of the safety systems when a DTC (Diagnostic Trouble Code) is set. This is done as the control systems can no longer rely on sensor data as at least one of the sensors (and maybe many more) are reporting a fault.

As this is the first time you have seen the DTC and the weather conditions had drastically changed, I do not think there is any reason for major concern. If the DTC occurs again under similar conditions I would consider it a bit of an anomaly BUT if it continues to reoccur under other conditions I would be sure to get it checked out by a trusted local workshop or local dealer.

You should be able to reset the DTC with your code reader. If your reader does not have that function removing the battery negative cable and pressing on the brake pedal will reset the ECU and should clear the DTC.

As the ECU is being reset the vehicle will be harder to start the next time.

Hope this helps,

Seagrass

 

@seagrass thank you for the response. This is conforting to hear. I went ahead and cleared the code. I'll see how she performs the next few days.

 

My '11 3.6r used to do that.Also the torque converter would unlock if the car slowed to 5-15 mph and when throttle was applied revs built freely like in neutral and it would engage again so hard it hurt. I replaced all factory ground wires with at least double the gauge,used 4ga to replace straps and added many new ones that reached the the rear subframe to reduce anomalies of voltage spikes and flow insufficiencies. Unfortunately when it would do xmas tree dash the converter wouldn't lock and driving to a safe spot to disconnect the battery where I live meant occasionally topping a mountain or moving with traffic for miles. That slippage and added heat in addition to the torque converter grabbing hard enough to chirp the front tires necessitated a rebuild. I added a large cooler to the tranny in line with the one in the radiator.After the fluid left the rad it went to the cooler mounted in front of the radiator and ac cooler for max efficiency.Florida Torque Converters made the new unit to mostly stock specs and the issues never resurfaced.Dealership reflashes of the tranny computer were ineffective. So my experience with it says grounding upgrades are needed which also ended the blowing of every rear bulb at once grr.

 

Due to holidays I finally got a new battery. This is the second battery I’ve bought for this car; so 3 batteries in all. I replaced it with an Optima Red Top because the last one I had lasted forever.

I cleared the code, but have not had a chance to drive far. So far the only issue is that the front passenger side window does not work from the driver controls and automatic does not work.

So my experience with it says grounding upgrades are needed which also ended the blowing of every rear bulb at once grr.

Holy crab that sucks. I’m not happy about how fast this car goes through batteries. I’ll follow your lead and beef up grounding. What do you mean when you say replace the straps? What straps?

This fault is diagnosed as P219C (cyl 1) in the FSM.

…I'll put up the full diag tree.

Thank you. I have tried to find the FSM in the past. Is this not available on the internet in PDF form or did I get bad at Google?

Is AF MAF at the beginning of the sentence?

Edit: I found this thread that’s related to my window issue. Sounds like a new window switch is required.

Gen 5 - Passenger Window Problem (different from others)

The RF passenger window in my 2017 Premium quit working from the driver switch. For about two days, it worked occasionally from the passenger switch but without auto up or auto down functions. Then it quit working completely, in the up position. I have checked all the fuses dealing with power...

www.subaruoutback.org

 

This fault is diagnosed as P219C (cyl 1) in the FSM. Check battery, grounds, AF sensor connector for water, AF sensor output using a scan tool, vacuum leak or gap between MAF and throttle, exhaust leaks and fueling.

Post up whether it comes back or not within the next 100 miles or so. If it does, I'll put up the full diag tree.

 

AF is Air Fuel, the front O2 sensor is a wideband air/fuel sensor.

Go-to SL-i.net and in their search bar type"factory service manual". There's a page on that forum with ALL FSM for Legacy, Outback. Impreza and Foresters. It will send you to a storage site in New Zealand. It's safe.

Edit:. This page Subaru Factory Service Manuals (FSM) - Every Model - USDM/EU

 

Ground straps.The uninsulated braided wires.Metal fatigue and corrosion from environmental factors ruin them pretty quickly.I have lots of power and ground wire bits from past audio installations around and I picked up a new 2ga preterminated battery to engine,chassis,and alternator ground from walmart that was worth every penny.Very important to maximize flow potential there.It may have sufficed alone but since it can cause such havoc I went overkill.An extra ground wire connecting the battery or engine to the rear prevents excessive corrosion in the rear subframe and even helps premature wheel bearing failure.Inadequate flow from the factory can create voltage spikes in these cars.Their smart alternators work well with these upgrades but can be a headache if not.If the negative battery terminal is wet or corroded more than the positive,odds are poor grounding is facilitating an undercharging condition.The first amplifier I installed in mine wouldn't even turn on due to it.Frustrating and puzzling since my work was good.Frequently mechanics forget to reinstall ground straps too.Mine was missing every one.