P010100 (Maf) and P245700 (Egr cooler temp) codes....

seismic22

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Hi everyone,

Before setting off on a 500 mile round trip yesterday in my wife's newly purchased 2016 T6 Kombi (private sale, 90,000 miles) I did a code scan on the van and a P010100 code showed up related to the Mass Airflow sensor. On the first leg of the journey, my wife did the first half of the driving and I monitored the presence of codes (as well as DPF data and other live data) and the code kept coming back. Later in the journey the code stopped coming up and was replaced with a P245700 code that then kept coming up in relation to the temperature of the EGR cooler.

The seller of the van a few days ago advised it is running a stage 1 map that includes the deletion of the EGR from the ECU. EGR blanks have NOT been fitted yet but it was/is my intention to do so. The Van seems to be regenerating the DPF just fine and drives considerably better than our other standard 150, overall it feels much more powerful and much much smoother albeit perhaps a little flat at sub 2,000 rpm at low speeds.

The only other matters of note are:

A) There appears to be quite heavy oil misting to the lower joint of the turbo to charge cooler pipe

B) I have noticed the rocker cover appears to be leaking and oil is noticeable across it's full width.

C) I cleaned the MAF before setting off on the journey noted above.

D) The van has recently had the cambelt, water pump, crank seal replaced and a full service including fuel filter undertaken. I also gently cleaned the MAF with contact cleaner.

E) Coolant level in the last 400 miles has remained the same.

Gut feel is to blank the EGR appropriately and monitor the oil misting to the joint between the turbo and charge cooler connection, possibly then replacing the seal in this location but also investigating if there's a leak from where the breather goes into the manifold down there too.
Only other thought was to try and check the intercooler for any leaks...

Does anyone else have any advice that may help me in solving the issue...?

Many thanks

Photos:

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Thank you. The engine code is CXHA so 150ps.

I had searched and keep on searching old posts on here but nothing seems to align quite the same with my situation. I have checked the intercooler as much as I can and cannot see any leaks. Only oil misting I can see is on joint of the manifold to charge cooler pipe as per the pictures above but having cleaned it up as best I can with brake cleaner, I can't see any further oil misting in the last 350 odd miles.
 
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Thanks. CXHA rules out the intercooler as the engine doesn't have the air cooled intercooler. Instead on top of the engine there is liquid/coolant cooled charge air cooler (as VW calls it). So unfortunately the obvious fault was also ruled out.

Anyways, the code
P0101 00 - Mass Air Flow Sensor (G70) - Implausible Signal
indicates that the values reported by the sensor do not make sense thus "Implausible signal"

Just need to figure out what values and why...

Unfortuantely OBDeleven screenshots are not very useful as so called "freeze frame" (a snapshot at the moment of the fault) is not decoded.
Can you find the freeze frame of the fault somewhere else in OBDeleven???

1756016996634.png

Below an example how VCDS has decoded the data (on another Transporter CXHA) where the culprit was quite obvious.

25792 - Mass Air Flow Sensor (G70)
P0101 00 [032] - Implausible Signal
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Status: 00000001
Fault Priority: 2
Fault Frequency: 1
Mileage: 118429 km
Date: 2050.01.21
Time: 00:00:20

Engine RPM: 0.00 /min
Normed load value: 0.0 %
Vehicle speed: 0 km/h
Coolant temperature: 24 °C
Intake air temperature: -29 °C
Ambient air pressure: 990 mbar
Voltage terminal 30: 11.585 V
Unlearning counter according OBD: 40
Air mass at air mass meter 1: 0.0 kg/h
Standardized air flow ratio: 1.000 counts
Exhaust recirc.valve 1 bank 1: posit.feedback - Actual value: 0.30 %
Throttl.valve adapt. 1 bank 1: posit feedback - Actual value: 0.00 %
Charge air pressure: specified value: 0.000 bar
Absolute intake pressure: 99 kPa abs
Mean injection quantity: 0 mg/stroke
Index of current engine mode: 4
Index of next requested engine mode: 4
Index of engine target mode: 4

Anyways, as the most common reason for P0101 is an air leak - don't you think you actually have quite an obvious air leak (below)?
the oil misting to the joint between the turbo and charge cooler connection,
There is always tiny amounts of oil in the air intake - as crankcase breather joins air intake path just before turbo intake. Tighten up the leaking joint?



P245700 code that then kept coming up in relation to the temperature of the EGR cooler.
it is running a stage 1 map that includes the deletion of the EGR from the ECU
A bit contradicting information as without EGR also the EGR cooler is just obsolete. Perhaps ECU has detected that EGR cooler (coolant) pump is not performing well?

You could monitor (log) EGR cooler input and output temperatures to see if there is any discrepancies between those two (yes OBDeleven can do it).
 
Right, sorry for the slow response / update, I was on holiday in the van when I was trying to work out what was wrong and then I was unsuccessfully trying to get obdeleven to show freeze frames.

So..I've solved the code issues by fitting EGR blanking plates. This means that whilst the EGR had been mapped out and shut, I expect the valve was faulty/coked up and wasn't able to fully shut meaning EGR flow was being picked up when the ECU wasn't expecting any etc (put in simple terms at least)....Done 150 odd miles since putting the blanks in now, codes would have popped up in just a couple of miles previously...

Re the oil misting - the bolts holding the turbo to charge cooler felt tight enough but I gave them both another turn and I can't see anymore misting at the moment so fingers 🤞🏼. The van does sound a bit more "boosty" than our other T6 150ps though....
 
Re the oil misting - the bolts holding the turbo to charge cooler felt tight enough but I gave them both another turn and I can't see anymore misting at the moment so fingers 🤞🏼. The van does sound a bit more "boosty" than our other T6 150ps though....
Probably a hardened / flattened O ring at the joint, I thought I’d seen the same leak point on the Forum before but can’t find it.
It might be worth sourcing a replacement O ring / seal now before it eventually leaks again.
The boost pressure on the biturbo is much higher than a 150ps.
 
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