Hello all, I am looking for help on my newly purchased S-Max 2011 (2010.5MY). It was sold as not working but it almost works.

When cranked it struggles to start and takes a few seconds. Then it idles a bit rough, drops from 800 to 500 revs, goes back up, does it again and the third time it drops to 0. But when I picked it up I drove it home. It was a hot day and it idled long enough to heat up. When hot I could coax it to drive and it slowly picked up speed, and at 1500-1800 revs it drove almost like normal. After about 20 miles I had to stop at an intersection with a slight upwards incline and instead of moving it started huffing and puffing and smoking very badly from the exhaust - most likely a regen. I turned it off, cleared fault codes and got it to drive like before the last 5 miles home. Forscan error codes before resetting are below. I have a hard time believing that it really is the air flow since the car works well except for idle speed.

The seller wanted to get rid of it to transition to an EV and I got it for a song. Now I hope to get many more miles out of it. Hopefully some of you elders have good suggestions. I work on it with one of my mates and our plan next is to loosen the DPF a bit to create a bypass for the exhaust just to test if there is a blockage that is killing the idle but the turbo can overcome. Also we are thinking maybe the EGR is stuck somehow. If you have any other suggestions or maybe an idea to what codes to read in Forscan, please let me know. Thank you.

It is a 2.0 TDCI 163 HP with the Powershift 6DCT450 transmission.

Thank you for all input

Jeppe

===PCM DTC P00BC:64-27===

Code: P00BC - Mass or Volume Air Flow 'A' Circuit Range/Performance - Air Flow Too Low

Additional Fault Symptom:

- Signal Plausibility Failure

Status:

- DTC Present at Time of Request

- Malfunction Indicator Lamp is Off for this DTC

Module: Powertrain Control Module

Freeze Frame #1:

-EVENT_TIME: 51596644 s (Sun Apr 26 16:51:27 2026) - Event time

-TOTAL_DISTANCE: 337435 km - Total Distance

-MODULE_VOLTAGE: 15.0 V - Control Module Voltage

-ESTSECRK: No - Engine status - engine in crank

-ESTSERUN: Yes - Engine status - engine running

-INCAR_TEMPERATURE: 28 °C - In car temperature

-OUTDOOR_TEMPERATURE: 13 °C - Outside temperature

-PWR_MODE_QF: Power Mode Undefined - Power Mode Quality Factor

-LOAD: 0.00 % - Calculated Load Value

-ECT: 72 °C - Engine coolant temperature

-MAP: 101.0 kPa - Manifold absolute pressure sensor

-RPM: 1316 1/min - Engine Revolutions Per Minute

-VSS: 33.0 km/h - Vehicle Speed

-IAT: 15 °C - Intake Air Temperature

-MAF: 1.50 g/s - Mass Air Flow

-FRP: 43200.0 kPa - Fuel Rail Pressure

-BARO: 100.0 kPa - Barometric pressure

-APP_D: 0.00 % - Accelerator Pedal Position D

===END PCM===

===SASM DTC ===

Successful DTC reading, no error codes found

Module: Steering Angle Sensor Module

===END SASM===

===ABS DTC ===

Successful DTC reading, no error codes found

Module: Antilock braking system

===END ABS===

===PBM DTC ===

Successful DTC reading, no error codes found

Module: Park Brake Control Module

===END PBM===

===RCM DTC ===

Successful DTC reading, no error codes found

Module: Restraint Control Module

===END RCM===

===HCM DTC ===

Successful DTC reading, no error codes found

Module: Headlamp Control Module

===END HCM===

===PSCM DTC ===

Successful DTC reading, no error codes found

Module: Power Steering Control Module

===END PSCM===

===BCMii DTC C1D21:05-6C===

Code: C1D21 - Wheel module

Additional Fault Symptom:

- System Programming Failures

Status:

- DTC Maturing - Intermittent at Time of Request

- Malfunction Indicator Lamp is Off for this DTC

- Test not complete

Module: Body Control Module

Freeze Frame #1:

-EVENT_TIME: 51596993 s (Sun Apr 26 16:57:16 2026) - Event time

-TOTAL_DISTANCE: 337441 km - Total Distance

-MODULE_VOLTAGE: 15.0 V - Control Module Voltage

-INCAR_TEMPERATURE: 28 °C - In car temperature

===END BCMii===

===TRM DTC ===

Successful DTC reading, no error codes found

Module: Trailer Module

===END TRM===

===SRM DTC ===

Successful DTC reading, no error codes found

Module: Speech Recognition Module

===END SRM===

===DSM DTC ===

Successful DTC reading, no error codes found

Module: Driver's Seat Module

===END DSM===

===PDM DTC ===

Successful DTC reading, no error codes found

Module: Passengers Door Control Unit

===END PDM===

===DDM DTC ===

Successful DTC reading, no error codes found

Module: Drivers Door Module

===END DDM===

===PAM DTC ===

Successful DTC reading, no error codes found

Module: Parking Aid Module

===END PAM===

===HVAC DTC ===

Successful DTC reading, no error codes found

Module: Heating Ventilation Air Conditioning

===END HVAC===

===RFA DTC ===

Successful DTC reading, no error codes found

Module: Remote Function Actuator

===END RFA===

===ACM DTC ===

Successful DTC reading, no error codes found

Module: Audio Control Module

===END ACM===

===IPC DTC ===

Successful DTC reading, no error codes found

Module: Instrument Panel Control Module

===END IPC===

Well, there's a signal plausibility on the MAF (?) sensor so that needs investigating?

3 minutes ago, Shearers said:

Well, there's a signal plausibility on the MAF (?) sensor so that needs investigating?

True but would a faulty MAF stop manifesting itself at higher revs, ie when the turbo kicks in? Genuine question, I have no idea myself

5 hours ago, Daneontheroad said:

I have no idea myself

Neither do I but if that is a hard fault i.e. clear them and it returns then it's something that needs attention?
You also state fault codes were cleared, which were they? (as I say, all the chaff from Forscan is confusing, the actual codes only are needed)
And, as it's new to you you don't know the service history, fuel filter is Achilles heel, along with looking for bubbles in the fuel line, air leaks etc etc at a basic level.
Plus you "assume" the smoke is a regen - what does Forscan say about DPF pressure differential to rule that out (the vaporiser if you have one) needs checking at some stage if the pressure is proved to be high and no need to remove DPF.
Then regarding your guess on EGR, and turbo, Forscan, I think, may have demanded and actual values and a reset procedure so that could be looked at.
Sorry to bang on but I can only state what I suggest for a similar but older vehicle (may not have the vaporiser which means there could be other issues with DPF system, etc)
We are just waiting for someone else who can wave a magic wand go straight to your problem, without seeing the car, from a distance using car telepathy rather than codes, live data and testing!
You could, of course change the turbo, EGR, DPF and all associated sensors like some garages would suggest at your expense! 😉

15 hours ago, Shearers said:

Neither do I but if that is a hard fault i.e. clear them and it returns then it's something that needs attention?

The codes in the post are from before I cleared them. And yes, in case of blockage there ought to be something from the differential pressure sensor on the DPF.

The thing about the MAF is that apparently it sometimes reports errors that are related to a leak downstream in the hose or intercooler, I have been told.

I'll try a few things the coming Sunday and get some more data too. Thank you for your input

@Daneontheroad if all else fails, pedal to the metal until the next fill up, reducing idle time to a minimum! 😂

One simple but serious suggestion though is make sure your battery is in top shape. If not, you can find that although the car works as normal, Forescan will throw up some odd codes here and there which are down to nothing more than the battery being in less than top condition. So, you MIGHT find that a new fully charged battery reduces the number of codes (no guarantee, but that's what I found).

id start at the air filter lol

unplug the maf see if it will idle

Short update: I looks like the culprit is the pressure converter/Turbine control valve. When I disconnected the vacuum hose from it, the engine would idle and after pulling vacuum on the system manually it worked as designed - albeit a bit rough - for a little while. Then it quit again. Alternatively the problem might instead (or also) be the turbo actuator sticking, maybe caused by sticky vanes, but I'll try changing the valve first. It is an easy, low cost job, and the actuator moved smoothly and silently when vacuum was applied manually.

I still don't quite understand how the turbo can stop the engine from idling but pulling the hose off the valve had an immediate effect.

I had a spare MAF sensor lying around and installed it afterwards for good measure but I don't really believe anything was wrong with it. Might reinstall the old one for experiment's sake after I get the new control valve installed.

Thank you for all input

That sounds like progress and goes to show codes don't tell the whole story although air flow is related to turbo (if the amount of boost isn't correct, it may produce a "plausibility error"?)
Whilst changing the solenoid valve may be necessary, the free movement of the vanes is crucial, then the vacuum actuator, then the solenoid valve then the wiring and, of course vacuum pipes - have I covered everything Guys?

Tried to quote-reply twice without the comment showing up so here it is w/o quote: Yes, it was the plausibility error.

Ah well, changing the vacuum valve did help but the problem persists. We tried disconnecting sensors and vacuum hoses sequentially and have come to the conclusion that the turbo vanes get stuck sometimes. Is that an automatic replacement of the turbo or can I clean the vanes and surroundings and refit the unit? And what is the easiest way to get to it since it is so well hidden below?

disconnect the turbo at the cat under the car at the v band clamp

spray "mr muscle expanding oven cleaner" inside the turbo side. seal with a rubber glove or a rag as it will expand out, manually move the actuator back and forth a few times over an hour if you can get to it

reconnect the cat

works a lot of the time

10 hours ago, Swearwolf said:

disconnect the turbo at the cat under the car at the v band clamp

spray "mr muscle expanding oven cleaner" inside the turbo side. seal with a rubber glove or a rag as it will expand out, manually move the actuator back and forth a few times over an hour if you can get to it

reconnect the cat

works a lot of the time

Sounds like something I can handle 😁 Will try next weekend. Thx

11 hours ago, Swearwolf said:

disconnect the turbo at the cat under the car at the v band clamp

spray "mr muscle expanding oven cleaner" inside the turbo side. seal with a rubber glove or a rag as it will expand out, manually move the actuator back and forth a few times over an hour if you can get to it

reconnect the cat

works a lot of the time

Oven cleaner did make a difference but not enough to declare problem solved. The positive effect indicates, however, that soot and gunk in the vane mechanism is indeed the root cause of the problem. Next weekend: Turbo off to be taken apart and get a thorough cleaning.

Any tips on removing the turbo? I'm not looking forward to that but it must be said that it wasn't too bad getting it opened and the oven cleaner in