Simultaneous "Check Engine", Traction Control and Cruise warning lights came on today....what's wrong? 2010 Forester Petrol

[Peroni]

Driving along slowly on an "A" road, pulling my trailer, around 50mph and the Check Engine and Skid Control and Cruise warning lights all came on. Cruise light is flashing green which I guess means it is inoperable at present. 

I'm wondering what this could be? I hope it's simply a sensor getting an out-of-range reading and deciding to throw an error and not something ghastly and expensive. Car is an 2010 2.0 litre X Petrol, manual with 80,000 miles on it. 

Does anyone have an idea what could cause this and how to investigate and/or fix it cheaply? I need to save money because covid has wrecked my business.  

Car does not seem to be lacking in performance, but hard to tell with a 600kg trailer on tow. No other issues apparent, ticks over and sounds the same as usual. 

Help!

[Peroni]

Managed to get the fault code using this youtube video and the code is P0032. This seems to be an oxygen sensor related problem (not cheap!) so I shall investigate that route.

 

 

[Mr B]

Any other codes ?
If you got a laptop look at using FreeSSM software and a cable that costs around £10 .
Android app and dongle good option too but good dongles cost 20 to £40 .
If it is O" sensor they not crazy money, only use Denso and front is under £80 and rear of cat is about £40 (can be found on eBay)
P0032 Heater circuit code, that easy do some checks with basic multimeter and google youtube have some subaru specific guides that probably help ...

[Peroni]

Cheers Mr B.

No other codes showing (the method in the video should be able to show multiple codes).  I'll probably get one of the data cable thingies to be sure.

O2 sensor heater...hmmm. Seems funny that would come on during a drive on a warm day. I'd have thought that would only be active on cold start up? I have a sense that the codes can't always be trusted 100%, although they point in the general direction.

I'll buy a Denso O2 sensor then if they are the legit ones. No point in scrimping and adding further gremlins to the system.

Any tips for getting the old O2 sensor out safely? Are they tricky? It all looks quite clean around the sensor, can't see any rust.

[Mr B]

The heater circuit speeds up initial response of sensors, The ecu has reference bias voltage values on the heater circuit and flag a code when these values seen as out of normal range .
Once fault detected and present the computer logic going do it's thing .
02 heater faults easy diagnose, simple visual inspection of wiring at sensor for obvious damage/corrosion and power/ground checks with test light or dmm and finally resistance value of heater element in the sensor with dmm .

Sensors can be tight but if they not looking corroded thy generally come out pretty easy  . If sensor known bad you can cut wiring tail off and go to town with what ever wrenches/sockets you got that going work .

[Peroni]

Finally got round to fitting the replacement sensor (Denso brand, via eBay, £113). An easy job, for a change, since the old unit was not seized. Managed to get it off with a shifting spanner (I know, wrong tool for the job). Borrowed a 22mm spanner from neighbour to fit the replacement, along with his OBD 11 Scanner.

I tried to test the old one before opening the package on the new one, but could not get any readings from any of the pins; open circuit across all pins with the unit unplugged. I was told to expect 5ohms across pins 3 & 4. Could be my multimeter though, wasn't sure I was reaching the metal connectors inside the block.

Anyway , new unit fitted, Battery re-connected and fault still showing. It took a "delete code" input with the OBD reader to make the fault go away. All sorted now.

Thanks for the help folks, with special mention to Mr B. 

[Mr B]

13 minutes ago, Wulbert said:

 Managed to get it off with a shifting spanner (I know, wrong tool for the job).

if it works it the right tool for the job lol ...
Job jobbed .

[Peroni]

Blinking’ hell! Out on a long run today and 20 miles in, driving to conserve fuel at a steady 40mph, the warning lights come on again.

Interogating the fault codes using the trip button/lights on/off method throws this code:

P0420

As a bonus, I also have:

C0072

C0057

C0071

which are “body codes”? 
Im gutted to be honest, planning to sell the car next month, I’ve just spent £113 on the new sensor and now have a raft of other “faults” to investigate. 
I wonder what is causing the P0042 code and if it can be related to the previous problem and the new C codes? 
Can’t do anything about it right now, I’m the middle of a forest. 

[Mr B]

P0420 is cat efficiency, this is calculated from readings of front rear O2 sensors and a lazy sensor or exhaust leaks can cause this code .

The other codes are all related to same issue of steering angle sensor fault or wiring/connection/signal issue with stability control .

Both issues really need professional scan tool with experienced user as first step of diagnosis to review sensor readings/values for clues of problem part .

Newer cars are total ballache, the older vehicles up to early 2006 are far more reliable and low maintenance thus low costs .
I suspect you be far better off hunting down a real nice clean sensible mileage 2003 to 2005 Forester SG example .
Newer cars are complete waste of money and time from what I witness daily ...

[Peroni]

2 hours ago, Mr B said:

P0420 is cat efficiency, this is calculated from readings of front rear O2 sensors and a lazy sensor or exhaust leaks can cause this code .

The other codes are all related to same issue of steering angle sensor fault or wiring/connection/signal issue with stability control .

Both issues really need professional scan tool with experienced user as first step of diagnosis to review sensor readings/values for clues of problem part .

Newer cars are total ballache, the older vehicles up to early 2006 are far more reliable and low maintenance thus low costs .
I suspect you be far better off hunting down a real nice clean sensible mileage 2003 to 2005 Forester SG example .
Newer cars are complete waste of money and time from what I witness daily ...

Thanks,

Yeah, after I sell it, I will be running nothing except a 2012 Honda Jazz. We will see how that pans out. My previous Jazz was a 2005 model and was virtually maintenance free for nearly 10 years apart from corroding brake pipes, a known fault.  Wish I'd kept it to be honest.

I'd actually prefer an older model Forester, I far prefer the looks and field of vision of the older models, especially the pre-2006 ones.  I never managed to find one without corrosion though (living in Glasgow doesn't help, lots of salty roads).

I'll have a good visual inspection of the exhaust system when I get a chance and check any connections. I have no clue about the "steering angle sensor" didn't even know there was any such thing.  I'd love a car with no computer some day; just carbs and electronic ignition (points ignition were crap).

[Mr B]

Yes Scotland and corrosion is an issue. Can still find pretty good examples down my way, automatics tend be easier find clean than the manuals .
I big fan of electronic injection but not a fan of current trend of electronics and electrical control when not really any benefit and engineered poorly in all areas from programming, component quality & even poor choices of location of electronics in the vehicle .
All we see these days is ever increasing electrical issues and short life components that getting worse the newer the car is.
The repair costs can be pretty crazy too, reality is driving a early 2000's Forester until end of viable service life vs a current Hybrid/EV would be minimal cost and hassle and probably even better for environment over EV considering potential short life of EV and fact you using fossil fuels make the majority of the electric .

 

[Peroni]

With a new air filter and a fill up of premium unleaded the fault has cleared!

I realised that I had been driving extremely frugally (free-wheeling down hills, using high gears and a whiff of throttle) for over a hundred of miles, which may have triggered the error. I drove unti the cheap supermarket fuel my wife bought was all used up, fitted new air filter, filled it with premium and revved the engine hard through the gears for a long A-road drive. Check Engine light now off and has stayed off for a 300 mile round trip up north on the motorway. 

Car is driving much more smoothly on the new fuel too. The hesitation on part throttle is gone (although personally, I think the old carburettors gave a much nicer throttle response).