2006 xc90 2.5 P0111 non OE MAF fail, Volvo MAF only. Topic is solved

[blandis]

2006 XC90 FWD 2.5T with 196K.

Bought this in 08' as a CPO with 19K miles on it. Still runs great, and first time I have had an issue in years.

Last week noticed was not warming up all the way. Temp gauge was not at 12 o'clock like it normally is. Figured thermostat was bad, ordered Mahle brand thermostat housing with coolant temp sensor. Next day check engine light came on, code was coolant temp sensor. Replaced the thermostat (90 degree) and coolant temp sensor. Pulled battery cable to clear check engine light. No code since for anything temp or coolant temp sensor. Back to operating at 12 o'clock temp position as before.

Thought all was good. Drove a couple days and check engine light came back on. Assumed coolant temp sensor was bad even though it was new or I did not get harness clipped on properly. Pulled code and was MAF sensor. Clean and reinstalled, pulled battery cable and two days later code is back. I have no problem buying a MAF sensor and installing, but wondering if a few other issues could be related?

1. Prior to replacing thermostat and temp sensor the cooling fan would run on startup. Never did that before thermostat went bad. Temp has been in the 20s and 30's here in NH. Assumed it was linked to CE light and bad thermostat and coolant temp sensor so did not worry about it. Fan will shutoff eventually, so do not think it is an AC charge related issue.
2. Fan did shut of when car got to operating temp from what I could tell. Only drove it a couple days.
3. Post thermostat and coolant temp sensor replacement fan still came on at startup and idle was at 800 rpms. I pulled battery to shut off CE light.
4. Drove 2 days and CE light is back on. Now its MAF. Assume not related to thermostat/temp sensor. Cleaned MAF with CRC MAF cleaner. Pulled battery again, and got MAF code again after a couple days driving.

The idle and fan at startup are odd. Just went down and started it and same thing. *800 RPMs and fan comes on... its is 17 degrees out, and probably single digits with wind chill here in NH.

I try not to just throw parts at an issue. MAF bad makes sense. 196K on original, I have cleaned it before for same code. If it is bad, have got my moneys worth out of it no doubt.

Any thoughts on idle/coolant fan issue that popped up at the same time the car would not come up to operating temp? Any suggestion on next steps?

Again, not trying to cheap out on buying a MAF. Just dont want to throw parts at it if I need to be checking something else.

As always appreciate the help.

Brad

[matthew1]

What code(s)? Did you search on those here?

[blandis]

Have a generic code reader and get Code is P0111. Intake Air Temp Senor/Circuit Range Performance

My wondering is why the low idle at start up? And fan running? Not seeing that tied to MAF. Or is that an issue that is lingering from the thermostat/coolant temp sensor replacement?

Appreciate the help.

[cn90]

I was in Dallas in the summer 2022.
Visited "Pick and Pull" at 8835 S Central Expy, Dallas.
They have a lot of Volvos there.
I'd go there and pick an MAF for cheap (usually $30 or so).

FCPEuro:
- Bosch MAF $120
- Bremi MAF (very good brand) $88.

Just make sure it is Bosch, the newer the better.
Also, the lower mileage MAF is better.
Sometimes, the owner replaced the MAF before the junk yard final reasting place.
Usuakky junk yard does not have the odometer of the donor vehicle, but you can
google the VIN and hopefully you see the odometer reading.
Another trick is to look at driver's seat condition to get a rough estimate of the mileage.

[chitownV]

It’s cold in New Hampshire, be safe with the current winter blast.

Yea, first thought is to replace the MAF in case it actually is the cause. I’ve replaced MAFs on two XC90 2.5t’s and that did solve their problems for a while. That’s the first step. Get it from FCP because if there are any issues, they will warranty it for the lifetime.

Some others have had to replace the TMAP, temp & manifold absolute pressure sensor. These can get gunked up with oil over time. Some have tried to clean them periodically, but at nearly 200k miles, it’s probably best to simply replace it. It’s located between the driver’s headlight and radiator. You can remove the driver’s headlight assembly for additional access.

Don’t forget to double check for any intake boot leaks, like the boost pipe hose connecting from the upper cross over pipe to the intercooler, at the passenger side radiator. I also assume you have already completed the PCV service.

Btw, your code scanner should be able to clear the codes so you don’t need to keep on disconnecting the battery. If it doesn’t clear, then go to a local Autozone to get the codes read and cleared.

[blandis]

Appreciate the input. Ordered a new MAF and should be here by the end of the week I hope. Will re-snug all hoses fittings when I pop the hood again.

Code reader I have was at the shop, have it now so can clear/scan until I get this addressed. Will post with results once I get MAF swapped and drive it a couple days.

My big wondering is the fan and low idle at startup and is that linked to MAF. Seems reasonable that a bad reading could send a signal to PCM and cause both.

[ggleavitt]

P0111 is most likely an ECM-1320- Intake air temperature (IAT) sensor inlet faulty signal. IAT is part of the boost pressure sensor PN 31355464 as is noted above.

Code Description (VIDA source)- The diagnostic trouble code (DTC) is stored if the engine control module (ECM) detects that the signal does not follow a certain characteristic over a period of time (assume another temperature sensor is cross referenced). When this occurs, a default value for charge air temperature is selected.

Entirely possible that what you're experiencing with the startup fan and idle "could" be related to the IAT default value as there's also mention about catalytic converter preheating and air trim diagnostics being disabled.

Sensor resistance (as measured between pins 1 and 2, per the VIDA component description) should be as follows:
5886 Ω at 0°C, 3791 Ω at 10°C, 2510 Ω at 20°C, 1715 Ω at 30°C. Could absolutely be a problem with the sensor and as noted above, the entire intercooler path gets PCV crankcase oil vapor pushed through constantly, the reason that big intercooler hose is so oily.

PCV serviced with any regularity on this vehicle? I've had to replace a few MAFs over the years when I owned the '05, once after a standard 50k mile dealer service and once a few years later. I've never had to touch the IAT but I have seen a few threads where they got replaced.

Agree with @ChitownV, between sensor checking or replacement and intake path validation and/or cleaning, you're heading in the right direction.

[blandis]

gg and china appreciate the time and feedback.

Swapped a Valeo MAF and same P0111 code is back. It did seem to fix the fan and idle at startup for until CE light came back on.... one morning startup (this morning) but will take it.

Couple things to note. Swapped MAF and cleared with code via code reader. Drove it home and did not run well. Stumble at about 2500 RPM, 3000 would float and not want to rev. Got home pulled harness, removed battery cable. I did strip the bottom MAF mounting screw that goes into the top of the airbox. Top one is snug and Oring is intact and seems to be good. Do not see an issue as "if it is leaking it is to the airbox/intake side of MAF. Just thought it worth mentioning.

Will dive back into it early next week when I can pull it in the shop and work on it. Will do some testing and report back.

Again thank you all for you help and guidance.

[blandis]

Purchased a new Valeo MAF sensor (OEM supposedly) and installed. Still was getting P0111 code.

Ordered a used MAF online from salvage yard, made sure it was Bosch. Installed used Bosch and code has not returned in the last week and almost 300 miles. Low idle on cold startup and cooling fan running constantly is gone as well.

Appreciate the help and advice in getting this sorted. Wanted to close this out for those searching in the future.

[abscate]

Thanks for follow up Brad. If I read this right, non OE parts failed where a Volvo part succeeded. Good to know

Changed title to MVS format and search