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2016 XC90 check engine P0171

65K views 60 replies 31 participants last post by  jadedj 
#1 ·
Got a system too lean bank 1 error last week. I took the car in and they stated they replaced a faulty fuel pressure sensor and a gasket. They did the smoke test and found leakage on the super charger resonator. Also updated the cars software to the latest version. 1.5 days later the check engine light and same code are happening. Seems even worse now cause at a stop light the engine was under revving. It didn't do that before. Anyone else had this issue on their newer model XC90? I can't find anything about it except on older models
 
#3 ·
I had this long string of issues with my lemond car, they replaced PCV as well as breather hose, o2 sensors, supercharger resonator gasket and no fix. The day I got the new one it had a hundred errors and shifted like sh**.

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#4 ·
Dropped it off this morning and it hasn't moved. They didn't even look at it today which kinda annoys me. I called and asked if they had any news and they just said they will have to keep it til Monday and they were looking at it. Yet it still is parked out front and it's been unlocked all day. I finally decided to lock it with my app. We will see Monday if it's gonna be fixed.
 
#5 ·
Did you ever find out what this was?

My 2016 T6 with 64,000 miles has a P0171, they diagnosed as supercharger resonator leak, replaced gasket, I pick up the car and make it 2 miles before CEL reappears....now they are telling me they arent sure 02 sensor will fix it, but that is next course of action.....of course I am not longer under warranty
 
#8 ·
What wound up happening here?

I'm in the middle of a similar situation with my 2017 T6. CEL diagnosed as a cracked supercharger pipe, replaced and 10 days later CEL lights up again. Next morning, in walks the "turtle" and car was in reduced performance mode. Trucked to dealer and they're currently diagnosing. Working through potential fuel system problems, apparently.
 
#6 ·
Keep in mind that these cars are essentially moving computers with lots of sensors. The codes don't always pinpoint the specific problem. Often after repair the code is cleared then after driving it can come back. So it is a lot of diagnosis and replacement of parts. Hey I can remember the days when I had a Ford Flathead engine. It was a simple engine that used a lot of gas, had terrible emissions and constantly needed to have plugs, points, and condensers replaced. While it is no fun having your car sit at the dealership, Volvo is not alone, in that most all manufacturers have problems that are not always easy to pinpoint. Coming from the electronics world I can tell you that in general the automotive industry achieves close to 100% quality of components. However, you need to add the complexity of dealing with an uncontrolled environment of temperature, pressure, moisture, demand, etcetera. I am surprised sometimes in how well our modern cars perform given the many opportunities for failure that exist in any given component. I had one of the 2600 compliance Toyota Rav4EVs back in 2014. I had a airbag warning light come on. I ended up taking it in 4 times for repairs. After replacing many components of that system, they finally isolated a faulty airbag in the passenger seat. Sometimes it would take days for the dash lite to come on other times it would come on as I left the dealership. Go figure.
 
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#7 ·
VIDA should be able to help pinpoint the problem. It is not about more computers and software. Good software also makes it easier to monitor and troubleshoot issues.

Multiple service visits at cost of owner is detrimental to owner confidence.
 
#9 ·
Had the same issue with my 2016 D5
cracked pipe from intercooler to turbo
dealer replaced 2 pipes and said it is common issue for early models 2016 , was fixed in later models
to much pressure since its a small engine with both turbo and supercharger , the PVC pipes just not handling the pressure and also have some oil after the turbo...
i hope it will not return . also on diesel it can damage the DPF

in general in the engine there are about 5 pipes like this, better to replace all , any leak of air cause reduced power

i wonder how common indeed this issue for 2015-2017
 
#14 · (Edited)
Had the same issue with my 2016 D5
cracked pipe from intercooler to turbo
dealer replaced 2 pipes and said it is common issue for early models 2016 , was fixed in later models
to much pressure since its a small engine with both turbo and supercharger , the PVC pipes just not handling the pressure and also have some oil after the turbo...
i hope it will not return . also on diesel it can damage the DPF

in general in the engine there are about 5 pipes like this, better to replace all , any leak of air cause reduced power

i wonder how common indeed this issue for 2015-2017
12/30/2019 So they fixed the issue by replacing all pipes? My 2016 XC90 T6 same code came up 2 days ago, 3 weeks prior to that I felt slight hesitation when gently touching gas pedal while moving over 30mph. I was under impression that one of the coils are going bad. But the code came up with the following possible issues.

Causes of the P0171 code may include:

A faulty fuel pressure regulator
A weak fuel pump
A clogged fuel filter
A faulty powertrain control module
A vacuum leak
Faulty injector(s)
Faulty oxygen sensor(s)
A faulty mass air flow sensor

I'm following process of elimination, cleaned MAS, now trying to find out where the Sweed's hid the fuel filter on new models (not where it used to be on previous model XC90) Anyone know where to look for it? Also replaced spark plugs while I was going at it, 3 of them look fine but one is darker, not burned, just look smoked more than the other 3.

Can anyone who went trough this rough patch confirm that your car is now fixed and what caused the issue? :confused:

Update: 12/31/2019 Still not finding the fuel filter to replace. Meanwhile cleaned MAS and took the car for a test drive, the car drove nicely, check engine disappeared after about 13 miles. At that point I was jumping dancing behind the wheel but then I felt hesitation when accelerating, that happen again driving few more miles then the hesitation was more frequent and then at total travel distance of 40 miles the hesitation is now permanent. The fumes from the exhaust pipes smell like gas/acetone - check engine did not return but I'm expecting it to appear very soon.
Next step: it looks like the MAS could be failing so I'm planning to pull MAS from my wife's 2019 XC60 to see if the car likes it, if it does then I'll know for sure that my XC90 needs new MAS. I will report once again.
 
#10 ·
Running into the same issue. Check engine kicked on and almost instantly got lower MPGs. Have the local volvo shop looking at it without much luck, trying to reproduce it without luck.

Car seems to run fine, doesn't seem like any power loss. I'll have them check the pipes for any cracks but anything else recommended? It's a 2016 model as well.
 
#12 ·
I had a reoccurring CEL on my 2016 T6 and the dealer, over the course of 4 visits, replaced the oil trap (CEL came back), then replaced the fuel pump (CEL came back), then replaced the front O2 sensor (CEL came back) and finally the rear O2 sensor, and it hasn’t come back for about 3 months and counting.
 
#13 ·
I had a reoccurring CEL on my 2016 T6 and the dealer, over the course of 4 visits, replaced the oil trap (CEL came back), then replaced the fuel pump (CEL came back), then replaced the front O2 sensor (CEL came back) and finally the rear O2 sensor, and it hasn't come back for about 3 months and counting.
Good to know. I was told by one shop that the problem is somewhere in the emissions but they weren't sure exactly where. O2 sensor seems like a reasonable place to start.
 
#15 ·
I would start with the O2 sensors. From what I understand, the front one is readily accessible, but you have to drop the exhaust to access the rear one.
 
#16 · (Edited)
If the car has faulty O2 sensor I would assume a Check Engine light would appear? I had CEL on but now it's off.

Update on what I've done so far: I replaced all spark plugs, replaced all coils and new MAS. I no longer have the Check Engine light on but still feel that hesitation while driving/applying my foot on a gas pedal. The exhaust fumes no longer smell like gas/acetone - I guess I can describe it as normal smell that comes out from the exhaust pipes. What I did notice is that there is an Air leak that sounds like a farting noise somewhere in between the engine and the engine wall. I sprayed brake cleaner on all air lines to see if the engine will start choking on it to identify if one of the air lines sucking extra air, but I didn't notice any difference. That farting noise what appears to me as an exhaust air leak is more prominent when engine is cold.
Some of the guys reported that dealer replaced super charger resonator, could that be the case? But I don't see how that would affect the car to hesitate and jerk when accelerating.:confused:
 
#18 ·
Noticed something different today. The check engine light was on (per usual) but as soon as I filled up - it went away.

I noticed after a few min of driving that it hesitated slightly at a low speed.

Could it be something with the gas tank cap?


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#21 ·
I've seen leaks at various points going to the supercharger cause this code. The normal steps for fault tracing are:
-Smoke check the intake and check for leaks
-Repair any leaks if found or
-Try a front oxygen sensor if no leaks are found.

I haven't seen any other causes of P0171 on SPA cars yet. That doesn't mean others are not possible though.
 
#22 · (Edited)
Good advice, thank you!
After I replaced all 4 spark plugs and cleaned MAS I took the car for a test drive and this is when I notices that CEL light went away. However, the car still jerks forward while driving with RPM's under 2000. Since then I drove more than 100 miles and the check engine light has yet to reappear. :confused:

fladg: I see what you saying. Visually the flap is in brand new condition, no marks or deep scratches. But I am planning to pressure test it when I get the chance.

Update: 1/7/20 The car stalled couple of times on red light and stop signs. It did that when the car was in engine auto shutoff mode. Corporate Volvo confirmed that the vehicle has Platinum extended warranty, I wonder if they'll cover 100% to fix this issue.
 
#25 ·
Did that fix the issue? It seems that an air leak is common problem on these vehicles and Volvo is yet to admit it. West Chester PA Volvo Dealership performed a smoke test on my XC90 and found an air leak "a supercharger needs to be resealed" they say. Whatever that means. The good news is that this job will be covered under the extended warranty or otherwise it would cost me $4500 I really hope that this will fix the issue. I will update once again once I get my volvo back.
 
#31 ·
Hi all, 2016 XC90 Inscription here...

Got the CEL code P0171 recently and took it to dealership. They made the fix which states: "tech scanned and found ecm-p017100, tech fault traced vacuum leak and found loose vacuum hose, tech secured hose and reset fuel air adaptations and performed ecm updates"

They are not telling me which vacuum hose was loose. Does this sound like the supercharger issue that is being discussed above? Should I be concerned?
 
#41 ·
had the same code, used a cheap bluethooth obd withandroid car scanner and noted fuel trim at idle was over +30%, and at high rpms way lower, so vacum leak, in my case was the hose on the valve cover that was disconected, fix the leak and the fuel trim lowered but stil give me the code after some time.
used the same app to check the o2 sensor behavior, and seems to be ok, so decided to look at maf sensor readings and noted they look ok, BUT the value reading was kinda low on idle, and not very high when i blip the throttle.
long story short, removed the maf and cleaned with electric contact cleaner spray, the maf values raised and no more p0171.
used the same app to clear the code on the ecu
the maf sensor element is not visible so i have used the straw to spray the cleaner inside de maf.
my dealer was unable to identify the problem to, if you look at internet p0171 is a very generic code so its dificult to diagnose, i would recomend to clean the maf sensor because is just 2 screws and a can of contact cleaner.

sorry about my english.
im from brazil.
 
#42 · (Edited)
P0171 repair success: Smoked and vacuum test the intake, no leak. EGR, all good no leak, check valves holding and no issues. Deleted code, and reset ECM. With no check engine light and base fuel trims, engine idle for 10 min, fuel trims normal and no check engine light. As soon as the engine leaves idle at higher RPMs, fuel trims go beyond normal and P0171 check engine shows up. Oxygen sensors are all showing normal parameters but decided to change bank 1 oxygen sensor (first O2 sensor close to the engine). With new O2 sensor (it seem to be a new O2 sensor update part number) and ECM reset, started engine and fuel trims normal. High idle, fuel trims holding no check engine. Drive tested 40 km no more P1071. Hesitance at lower speeds seems to be gone also. (2017/ XC90 / T6 Momentum)

All this happened 120 km after taking it to my local Volvo dealer for service that included “fuel service”. I believe whatever fluid or fluid quantity used to flush the manifold and injectors ended up cooking my O2 sensor.
 
#43 ·
P0171 repair success: Smoked and vacuum test the intake, no leak. EGR, all good no leak, check valves holding and no issues. Deleted code, and reset ECM. With no check engine light and base fuel trims, engine idle for 10 min, fuel trims normal and no check engine light. As soon as the engine leaves idle at higher RPMs, fuel trims go beyond normal and P0171 check engine shows up. Oxygen sensors are all showing normal parameters but decided to change bank 1 oxygen sensor (first O2 sensor close the the engine). With new O2 sensor (it seem to be a new O2 sensor update part number) and ECM reset, started engine and fuel trims normal. High idle, fuel trims holding no check engine. Drive tested 40 km no more P1071. Hesitance at lower speeds seems to be gone also. (2017/ XC90 / T6 Momentum)

All this happened 120 km after taking it to my local Volvo dealer for service that included "fuel service". I believe whatever fluid or fluid quantity used to flush the manifold and injectors ended up cooking my O2 sensor.
Bummer we have to deal with it but that's exactly what my issue was as well.

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#50 ·
Me too. 2016 T6 with 65,000. Seals replaced and CEL was off when I picked it up. Told my husband I had read this is not a one shop stop fix and suggested we put some miles on it with a drive to the beach. 35 miles later, check engine light is back on. Timing for having to bring back to the shop couldn't be worse. ;-(
Happy to have read about this here so I was somewhat prepared.
 
#54 ·
FYI O2 sensor replacement DIY. The one that usually fails the driver side one, that send to the ECU Air/Fuel ratio...


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#57 ·
Adding to this conversation:
2016 XC90 inscription T6 with 83K miles
  • started getting code PO171, after resetting it, it would come back after a couple of days
  • checked the oil cap for suction
  • cleaned MAF

I was going to replace the oxygen sensors but before I could get to it, I got a misfire on cylinder 1.
when I checked the spark plug, the ceramic insulator had become loose and was letting air escape from the cylinder
I had seen this before and in my experience pointed to bad ignition coils (this happened to me on a nissan)
so I replaced:
  • oxygen sensors (since I already had them)
  • all coils
  • all spark plugs

it has been about 2 months and 2k miles and no longer get any codes.
So I would say that if you replace the O2 sensors and do a smoke test and you still get the error, replace the coils and spark plugs next.
 
#61 ·
I have a 2016 R-Design with about 116K miles and got this code too. I hear squeaking from the timing belt but not sure that has anything to do with this code (not likely). The difference is, my car runs totally fine so wondering if there's anything I can do myself on the cheap that might fix the code.
 
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