Car in Limp mode

[nu11eaf]

Last week my XC90 D5 PP started to hesitate under load, first time it was just once during the drive then next time a couple of times then it started doing it frequently and the tortoise popped up in the display and "engine reduced performance" warning came on, when I got home there was a very strong smell of fuel but it smelt like paraffin and there was a misty film on the rear window.
I scanned for fault codes and the mass airflow showed a fault and also a transmission/cooling system fault. I had the car recovered via Volvo assist to my local dealership and they have diagnosed 1, Split in charge air hose, 2, EGR pipe leaking resulting in fumes in cabin, 3, Engine coolant sensor fault that will require signal/wiring checking when new sensor fitted, they also spotted the offside front ball joint boot split.
The bad news is the parts have to be ordered and will not arrive until next Monday. Total cost £1140 +.
The good news is it will all be covered by my Volvo extended warranty.

[theonlyone]

I had the 'reduced engine performance' turtle today on my 2017 V90CC D4. The codes returned were P00BF 'Mass Airflow sensor B - circuit range/performance' and P2262 'Turbocharger boost pressure not detected'. This is the first time any fault has shown in 4 years of ownership, and it happened on a short trip, after a couple of weeks on the driveway. I reset it and tested again on the way back. It needed a burst of acceleration to trigger it again, and this time the codes were P00BE and P00BF, both 'Mass Airflow sensor B - circuit range/performance'.

Before I throw myself at the mercy of the dealer, anyone have any idea about what might be needed - is it a MAF replacement perhaps?

[nu11eaf]

I would check for leaks in the airflow pipes, my code indicated mass airflow fault but it was the leaking pipe which triggered it, I am glad I did not fork out for MAF sensor. I was sent a video of the leaking pipe filmed from under the car on drivers side.

[theonlyone]

Thanks nulleaf, I'll take a look at the weekend.

[theonlyone]

duplicate.

[theonlyone]

The MAF sensor is very accessible, so I’m also thinking about cleaning it with an appropriate product. A new MAF sensor from Volvo is about £300 before any labour charge. I’ve seen a few different aftermarket versions at anything between £80-100.

Does anyone have experience of cleaning or using aftermarket parts?

[wynnj]

Originally Posted by theonlyone

Does anyone have experience of cleaning or using aftermarket parts?

I cleaned one on a Mk1 XC90 D5 last year when trying to isolate an intermittent problem. After reading what I could find on the web I used a MAF specific cleaner; there's conflicting advice on whether you can use carb cleaner or not - I didn't want to take the chance. I can't remember the full sequence of events but I was getting conflicting or inconclusive DTCs. The MAF cleaning didn't sort it but I eventually traced it to an air pressure sensor which, on the D5, was fitted to the side of the intercooler. Changed that and the problem went away.

[Kev0607]

Originally Posted by theonlyone

The MAF sensor is very accessible, so I’m also thinking about cleaning it with an appropriate product. A new MAF sensor from Volvo is about £300 before any labour charge. I’ve seen a few different aftermarket versions at anything between £80-100.

Does anyone have experience of cleaning or using aftermarket parts?

If cleaning, make sure you use an appropriate cleaner like MAF spray or electrical contact cleaner... don't use anything else. Simply remove the sensor, spray it and let it dry for 10 mins or so before you put it back in. Make sure the engine is completely off when you do this, i.e. no ignition on.

With regards to aftermarket parts, many have had success with Bosch. I believe Bosch are the OE supplier to Volvo for these sensors. If you look at your existing one, its likely it has Bosch written on it.

[theonlyone]

Thanks both, I'll take a look in daylight tomorrow and find a MAP specific cleaner.

[theonlyone]

No joy with the MAF sensor cleaner. The turtle returned, and the same codes re-presented.

'P00BE MAF sensor B - circuit range/performance'
'P00BF MAF sensor B - circuit range/performance'
'P00BD MAF sensor A - circuit range/performance'

I then used electrical cleaner on the connector, and drove again. The A code disappeared on the next run, but I don't know if that can be interpreted somehow.

I could try an aftermarket sensor, but the existing one looks OK as far as I can tell, and of the air pipes I could see, they all looked intact. I think it's time to go to the garage.