MAF HELP Please T6 150

[Frank L]

(I posted this in another thread but no response as yet, hope starting a new one is ok in the circumstances.)
I am in Spain with my T6:150 : 2016 and my EML light came on, steady ie not blinking. (Not sure if it has any relevance but I had completed a traverse of the Pyrenees at slow speed on a scenic route - N260- well worth it).The vehicle drives perfectly, no loss of power, no noticeable coolant or oil consumption. The first VW garage I got to plugged in the OBR and said it had recorded sporadic EGR fault. That VW commercial vehicle service garage cleared the light and said continue driving as it might not recur. After about 300 km on fast roads the EML lit up again when climbing slowly on twisty roads into the hills. The next two VWCS garages I visited quoted one week and 2 weeks respectively before they could get to examine the vehicle. I’ve done another 250 km since then, no problems in terms of engine performance. I borrowed a simple OBR 11 reader, plugged it in, and it found fault code P0101, which its instruction booklet tells me is “MAF or VAF circuit range /performance”. I have a long distance to go on this trip. What might the consequences be if I continue disregarding the EML light? Any helpful advice would be much appreciated.

 

[WelshGas]

(I posted this in another thread but no response as yet, hope starting a new one is ok in the circumstances.)
I am in Spain with my T6:150 : 2016 and my EML light came on, steady ie not blinking. (Not sure if it has any relevance but I had completed a traverse of the Pyrenees at slow speed on a scenic route - N260- well worth it).The vehicle drives perfectly, no loss of power, no noticeable coolant or oil consumption. The first VW garage I got to plugged in the OBR and said it had recorded sporadic EGR fault. That VW commercial vehicle service garage cleared the light and said continue driving as it might not recur. After about 300 km on fast roads the EML lit up again when climbing slowly on twisty roads into the hills. The next two VWCS garages I visited quoted one week and 2 weeks respectively before they could get to examine the vehicle. I’ve done another 250 km since then, no problems in terms of engine performance. I borrowed a simple OBR 11 reader, plugged it in, and it found fault code P0101, which its instruction booklet tells me is “MAF or VAF circuit range /performance”. I have a long distance to go on this trip. What might the consequences be if I continue disregarding the EML light? Any helpful advice would be much appreciated.

I'm afraid I can't help you with your query but you might get more info if you post on the T6 Forum.

What's new

www.t6forum.com

 

[Frank L]

I'm afraid I can't help you with your query but you might get more info if you post on the T6 Forum.

What's new

www.t6forum.com

Thanks WG. Have posted now on T6 forum as you suggested.

 

[sidepod]

I’d check the date against the MAF fault, it may be an old one that was never cleared after the MAF was changed.
Usually a MAF problem results in loss of power.

It’s easy to check. Find it (air intake after the filter?), unplug it and drive the van. If it’s gutless then you know it’s not the problem. Obvs plug it back on again.

I don’t believe a MAF issue flags up on the dash.

 

[secret lemonade drinker]

Is your vehicle manual or automatic? MAF sensor helps auto to know when to change gear, you may find yourself driving an auto in manual mode when it fails completely with a large loss in power.

 

[Frank L]

Is your vehicle manual or automatic? MAF sensor helps auto to know when to change gear, you may find yourself driving an auto in manual mode when it fails completely with a large loss in power.

My Cali has a DSG gearbox and presently drives as effortlessly as always. The customary power and “ automatic” gear shifting to suit the conditions. Just one little steady yellow light.

 

[secret lemonade drinker]

The maf probably needs a recalibration or some muck is blocking part of the grid affecting its performance, they are finicky sensors and are expected to work within an allowable range, if the sensor reads low then you can get the light up. When they are changed, they need to be recalibrated. When VW service your vehicle and you think the gearbox has forgotten how you drive it is usually because they have optimised the maf instead of cleaning it. They are not cheap either, if it's still working I'd live with it to you get home

 

[Perfectos]

My Cali has a DSG gearbox and presently drives as effortlessly as always. The customary power and “ automatic” gear shifting to suit the conditions. Just one little steady yellow light.

The yellow light is a warning , loss of power will usually be when a Red warning light is lit or flashing yellow.

What happens when you unplug the MAF sensor ? There is usually a default setting that does not rely on the sensor (when disconnected)

You can clean the MAF with a specialist spray cleaner.

When was your last Regen ?
What add blue range fo you have left ?

Here is an excerpt for the code

P0101 Trouble Code - Mass Air Flow (MAF) Circuit Range/Performance Problem

 

[sidepod]

The maf probably needs a recalibration or some muck is blocking part of the grid affecting its performance, they are finicky sensors and are expected to work within an allowable range, if the sensor reads low then you can get the light up. When they are changed, they need to be recalibrated. When VW service your vehicle and you think the gearbox has forgotten how you drive it is usually because they have optimised the maf instead of cleaning it. They are not cheap either, if it's still working I'd live with it to you get home

MAF recalibration? New one on me!

 

[Frank L]

The yellow light is a warning , loss of power will usually be when a Red warning light is lit or flashing yellow.

What happens when you unplug the MAF sensor ? Their is usually a default setting that does not rely on the sensor (when disconnected)

You can clean the MAF with a specialist spray cleaner.

When was your last Regen ?
What add blue range fo you have left ?

Here is an excerpt for the code

P0101 Trouble Code - Mass Air Flow (MAF) Circuit Range/Performance Problem

Thanks Perfectos. I have about 3500 km range left in AdBlue terms. Not sure when last regeneration happened, think it might have been about a week ago.

 

[Frank L]

The maf probably needs a recalibration or some muck is blocking part of the grid affecting its performance, they are finicky sensors and are expected to work within an allowable range, if the sensor reads low then you can get the light up. When they are changed, they need to be recalibrated. When VW service your vehicle and you think the gearbox has forgotten how you drive it is usually because they have optimised the maf instead of cleaning it. They are not cheap either, if it's still working I'd live with it to you get home

SLD: thanks for your response. I’m tempted to do as you say, ie just keep going despite the light. I have about 700km to get home if I don’t go any further south (we had intended to travel down the coast for another 250km - until the light showed up ). I’m a bit concerned in case damage may result from carrying on. I read about the possibility of the engine going to limp mode , also the serious implications of the light turning from steady to blinking!

 

[Perfectos]

Thanks Perfectos. I have about 3500 km range left in AdBlue terms. Not sure when last regeneration happened, think it might have been about a week ago.

Regen should be every two hours of driving (typically) !
Does not sound right ?
Never heard of a MAF recalibration?!( It's an inanimate sensor, it either works or does not , clean works dirty will not ! )
The fact the issue happened whilst changing altitude may me an issue.
If you can clear the fault(s) check the dates and carry on. 300km between warnings is a significant delay !
If you can interrogate the last Regen, mileage time / date etc ?
Reset, get home.
Pls keep us updated. - do you have roadside / breakdown assist ?

 

[Frank L]

Regen should be every two hours of driving (typically) !
Does not sound right ?
Never heard of a MAF recalibration?!( It's an inanimate sensor, it either works or does not , clean works dirty will not ! )
The fact the issue happened whilst changing altitude may me an issue.
If you can clear the fault(s) check the dates and carry on. 300km between warnings is a significant delay !
If you can interrogate the last Regen, mileage time / date etc ?
Reset, get home.
Pls keep us updated. - do you have roadside / breakdown assist ?

Perfectos
Thanks for all advice.
Regarding re-gens , I don’t know for sure when the last one occurred; when I said ”last week” I accept that was not very helpful, but we have been on this campsite for 5 nights so I should have said I think it happened on the 3 hours journey to here which was mostly on motorway at 110km/hr The basic OBD reader I have does not facilitate the checking of dates or when the last regents was done. However another poster suggested getting a Carista, so I anticipate a delivery from Amazon in the next day or two. I’ll need to gen up on how to use it, life is a continuous learning process even for older folk ! Meantime, using the basic OBD reader, I chanced erasing the fault; then on start up and running engine for a while the EML light stayed off. We are hooked in to power with roof up etc, so I’ll need to set up for a test drive .

 

[Perfectos]

Perfectos
Thanks for all advice.
Regarding re-gens , I don’t know for sure when the last one occurred; when I said ”last week” I accept that was not very helpful, but we have been on this campsite for 5 nights so I should have said I think it happened on the 3 hours journey to here which was mostly on motorway at 110km/hr The basic OBD reader I have does not facilitate the checking of dates or when the last regents was done. However another poster suggested getting a Carista, so I anticipate a delivery from Amazon in the next day or two. I’ll need to gen up on how to use it, life is a continuous learning process even for older folk ! Meantime, using the basic OBD reader, I chanced erasing the fault; then on start up and running engine for a while the EML light stayed off. We are hooked in to power with roof up etc, so I’ll need to set up for a test drive .

Regen sounds normal, depending when the regen happened, next one should be soon, typically regen happens every 2 hours or sooner depending on the soot level, so it sounds like that's not an issue. Carista will be able to tell you when last Regen occurred and current soot levels, you can force a Regen to occur if you think it's not Regen ing correctly.
Sounds like Regen is not an issue.

Check all air intake hoses and air filter box for obvious leaks.
May be worth checking the air filter and inside the box to discount contamination, there should be no dust / residue at all i the air box above the air filter.
Check the electrical connector and wiring attached to the air intake, for obvious signs of damage etc, check the sensor is clicked in properly.
Note if you remove the connector you will get a yellow warning light that will require resetting.

Clearing the Fault code is a reasonable call, a garage would do the same and ask you to drive the van to see if it comes back on.

If the warning returns try to establish under what circumstances the warning light occurs. (Is it related to increase in elevation, low Revs under heavy load etc).

 

[Perfectos]

The maf probably needs a recalibration or some muck is blocking part of the grid affecting its performance, they are finicky sensors and are expected to work within an allowable range, if the sensor reads low then you can get the light up. When they are changed, they need to be recalibrated. When VW service your vehicle and you think the gearbox has forgotten how you drive it is usually because they have optimised the maf instead of cleaning it. They are not cheap either, if it's still working I'd live with it to you get home

You learn something every day

Ultimate Guide on How to Calibrate MAF Sensor: Tips and Techniques for Improved Engine Performance - Motor Riderz

Have you ever experienced poor performance from your vehicle’s engine? It could be due to a faulty Mass Airflow (MAF) Sensor. A MAF sensor measures the amount of air flowing into your car’s engine, allowing the engine control unit (ECU) to control fuel injection for optimal performance. However...

motorriderz.com

 

[Frank L]

Regen sounds normal, depending when the regen happened, next one should be soon, typically regen happens every 2 hours or sooner depending on the soot level, so it sounds like that's not an issue. Carista will be able to tell you when last Regen occurred and current soot levels, you can force a Regen to occur if you think it's not Regen ing correctly.
Sounds like Regen is not an issue.

Check all air intake hoses and air filter box for obvious leaks.
May be worth checking the air filter and inside the box to discount contamination, there should be no dust / residue at all i the air box above the air filter.
Check the electrical connector and wiring attached to the air intake, for obvious signs of damage etc, check the sensor is clicked in properly.
Note if you remove the connector you will get a yellow warning light that will require resetting.

Clearing the Fault code is a reasonable call, a garage would do the same and ask you to drive the van to see if it comes back on.

If the warning returns try to establish under what circumstances the warning light occurs. (Is it related to increase in elevation, low Revs under heavy load etc).

Perfectos.
Carista delivered to campsite less than 24 hours after ordering. No faults showing.

Regen sounds normal, depending when the regen happened, next one should be soon, typically regen happens every 2 hours or sooner depending on the soot level, so it sounds like that's not an issue. Carista will be able to tell you when last Regen occurred and current soot levels, you can force a Regen to occur if you think it's not Regen ing correctly.
Sounds like Regen is not an issue.

Check all air intake hoses and air filter box for obvious leaks.
May be worth checking the air filter and inside the box to discount contamination, there should be no dust / residue at all i the air box above the air filter.
Check the electrical connector and wiring attached to the air intake, for obvious signs of damage etc, check the sensor is clicked in properly.
Note if you remove the connector you will get a yellow warning light that will require resetting.

Clearing the Fault code is a reasonable call, a garage would do the same and ask you to drive the van to see if it comes back on.

If the warning returns try to establish under what circumstances the warning light occurs. (Is it related to increase in elevation, low Revs under heavy load etc).

Breaking radio silence , we decided to stick in a sunny campsite and enjoy it before working up the nerve to head for the ferry. Ordered Carista from Amazon, got it in less than 24 hours delivered to campsite . It confirmed all faults had been cleared by my basic OBD2 reader. Set off yesterday and drove about 400 km with no warning lights and no problems with engine performance . Refuelled and shortly after the EML lit up . Drove further 30 km to present campsite, again fully cooperative engine.
Connected Carista again with results as summarised below. (And lots more info, such an interesting device.)
Have cleared faults and will head north in last leg to ferry tomorrow . Live in hope! Thanks for all advice.

Basic OBD2 faults: 2

P0101 - Mass or Volume Air Flow "A" Circuit Range/ Performance

P2457 - Exhaust Gas Recirculation Cooling SystemPerformance

Engine faults: 3 (all listed as “Priority2)

P010100 - Mass or Volume Air Flow Sensor "A" Circuit Range/ Performance (Frequency 2)

PO46C00 - EGR Sensor "A"Circuit Range/Performance (Frequency 1)

P245700 - Exhaust GasRecirculation Cooler Efficiency. Below Threshold (Frequency 2).

Time since last Regen 0 hours

Distance since last regen 20 km

Soot level 8.9 grams

 

[Perfectos]

Is your coolant level normal when cold and is it a nice bright pink colour ?

 

[Frank L]

Is your coolant level normal when cold and is it a nice bright pink colour ?

Thanks Perfectos, to answer your question first, the coolant is indeed pink, and it's level is above the "Max" mark by about a cm.

I'm now home (happy day) though not without further adventure.

Following on from the earlier saga, I cleared the EML fault on the way to the ferry but it came on again after about 100km.
In total since then I've done about another 400 km. About 40km from home the coil light came on - flashing - in addition to the (steady) EML light.
Engine power reduced slightly at that point.

The faults now showing up on Carista are:

P010100 - Mass or Volume Air Flow Sensor "A" Circuit Range/ Performance
Odometer reading 116633 km
Engine rpm 1411.5 RPM
Coolant temperature 82°C

P046C00 - EGR Sensor "A" Circuit Range/Performance
Odometer reading 116624 km
Coolant temperature 30 °C

P040200 - Exhaust Gas Recirc.Flow: Excessive Detected
Odometer reading 117126 km. this is when the flashing coil light came on 114 km from the ferry and 37 km from home, engine performance dropped somewhat.
Vehicle speed 95 km/h
Coolant temperature 89 °C

(Not sure if it is germane but I have a feeling the AdBlue consumption rate may have risen in the last 800km)

Time since last DPF Regen 1 hour
Soot level 11 grams
Distance since last DPF regeneration 37 km. (ie 117124) this is pretty well when the coil light came on

Home at 117121km

So now I will source a VW garage to take on the repair challenge, complicated by a bit of a falling out I recently had with the nearest main dealer.

 

[sidepod]

Are those odometer numbers correct?

 

[Frank L]

Are those odometer numbers correct?

Sidepod:
Thanks for your interest.
Sorry.
Last odometer reading "Home" should have been 117161 not 117121