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Discussion Starter #1 (Edited)
I see that a lot of people are struggling with this kind of problems, so here are some suggestions how to resolve them, this could be a sticky thread (FYI).

Motor Control System Failure is universal message which appears on display when ever some error is recorded in engine ECU.
The safest way to determine the problem is connecting the car to diagnostics equipment (fo example K-line interface + FiatECUScan) and read which error is recorded, but here are some tips what else you should chack.



Symptom
-> Possible problem


Black smoke on exhaust & loss of power (possible MCSF error)
-> usually split Turbo-Intercooler hose, or Intercooler-IntakeManifold hose, or cracked Intercooler, that causes losss of air pressure from turbo, and surplus of injected fuel is unburned and turns to black smoke (check the hoses http://i32.tinypic.com/2v3rbqv.jpg and replace the cracked one
)

No power (no throtle response) below 2000rpm (possible MCSF error)
-> usually EGR valve is in stuck open position (there is a guide how to clean it and make it work again: How-to Fix the EGR on a 1.9JTD.pdf )
-> if you physically block the EGR with blanking plate on JTD M-JET or JTDM you will get permanent MCSF error
-> also could be defective MAF (Mass Air Flow) sensor (try disconecting the el. connector from MAF and do a test drive, if engine performance is restored with MAF disconected replace faulty MAF with new one http://i34.tinypic.com/1idefc.jpg )

No power below 3000rpm (possible MCSF error)
-> usually cracked vacuum hose for VGT regulation valve, so Turbo charger is always in high revs position (check these vacuum hoses http://i28.tinypic.com/2zqyc7q.jpg, and replace the cracked one http://i31.tinypic.com/ele2z9.jpg )
-> also may be jammed VGT regulation mechanism inside Turbo charger (Turbo charger http://i30.tinypic.com/2zgc2eu.jpg needs to be disassembled and cleaned/repaired http://i30.tinypic.com/29g1l3b.jpg )

Power cuts out after 2500-3500rpm (possible MCSF error)
-> usually jammed VGT regulation mechanism inside Turbo charger which is causing overboost and engine goes to SafeMode (Turbo charger http://i30.tinypic.com/2zgc2eu.jpg needs to be cleaned/repaired: http://i30.tinypic.com/29g1l3b.jpg )
-> also could be problem with faulty VGT selenoid (PIERBURG electro-vacuum valve #2 on pic. http://i28.tinypic.com/2zqyc7q.jpg) (check functionality with diagnostics, and replace if faulty, on 156 http://i52.tinypic.com/2d75y1e.jpg, on 147/GT http://i53.tinypic.com/rvzeyb.jpg)

Reduced performance/power, car not able to acheive the maxiumum velocity (possible MCSF error)
-> usually faulty MAF sensor, showing wrong mass air flow which causes reduced engine power (try disconecting the el. connector from MAF and do a test drive, if performance is restored with MAF disconected replace faulty MAF with new one http://i34.tinypic.com/1idefc.jpg )

Engine turns off when driving, or wont start (possible MCSF error)
-> usually failing crankshaft rotation sensor, or camshaft position sensor (to be sure check with diagnostics, and if one of these errors appears replace the faulty sensor)

Engine temperature between 50-60 degrees while driving
-> usually thermostat partially opened all the time, or opening to early, which is not good because combustion is not optimal and there is more soot generated in the engine (replace the thermostat, and temperature should be between 80-90 degrees)


More to come...
 

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VGT regulation mechanism inside Turbo which is causing overboost

How do you clean this & where is this located?
 

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Discussion Starter #3 (Edited)
VGT regulation mechanism inside Turbo which is causing overboost
How do you clean this & where is this located?

Here is the inside schematic of Variable Geometry Turbo charger:

On turbine side of Turbo charger you can see VGT mechanism (controlled by vacuum valve) with little vanes around the rotor which direct more or less exhaust flow to the turbine rotor.

If the car is driven mostly in town on low revs (especially if the car had chip tuning because more injected fuel generates more soot) soot/grime could deposit on that VGT mechanism and it can ge stuck:
- if it's stuck in low revs position it develops overboost at high revs (MCSF + engine goes to SafeMode)
- if it's stuck in high revs position there is no power in low revs

If some of that happens it's not really an easy DIY job (something like this: http://www.forddoctorsdts.com/articles/article-06-05.php ), and I would recommend you to go to specialist.
Best preventive for that is to blow out the engine regularly on motorway.
 

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Howdo!
I currently have GT diesel which is great, however had the car re-mapped and it was fantastic until every know and then it would come up with this Motor Control failure. The guy who fitted the map said it was because it was producing to much boost? He tried several maps but it kept happening? Truth be told I don't think he was that swept up on Alfas, he had just had the maps E-mailed to him from the company (A mapping company that has been recommended on the Forum) then he installed them. Fair enough he reverted the car back to normal and refunded me the cash. The error has never happened again. Thing is the car was so good when the map was fitted and running, I would like to get the car done again or could I be in the same boat again???

Cheers Pablo
 

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Howdo!
I currently have GT diesel which is great, however had the car re-mapped and it was fantastic until every know and then it would come up with this Motor Control failure. The guy who fitted the map said it was because it was producing to much boost? He tried several maps but it kept happening? Truth be told I don't think he was that swept up on Alfas, he had just had the maps E-mailed to him from the company (A mapping company that has been recommended on the Forum) then he installed them. Fair enough he reverted the car back to normal and refunded me the cash. The error has never happened again. Thing is the car was so good when the map was fitted and running, I would like to get the car done again or could I be in the same boat again???

Cheers Pablo
speak to gus at alfatune or pm him on here alfatuner in trade directory
 

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Have had the MCSF error for some time now. Got AlfaDiag and the OBD II cable and have read the following error:

P1238

which Smaky's list of codes has as

Fuel Pump Secondary Circuit Malfunction

Any ideas what this means and is it going to affect the car? Seems to drive ok. It's a remapped JTD.
 

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Ok,thats why I asked,clean EGR first if that doesnt cure it it needs a new air mass sensor,as
1238 is a common air quantity fault.;)
 

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Hi guys I've been having trouble with my 156 2.4jtd20v with the mcf coming up with the orange engine light up on the dash , it's got no power when it comes up but when I take it to. A mate of mine who plus it in the the computer it's coming up with fault code p1235 . When he resets the engine fault the lights go out and the car is much better when you go over 2000 rpm , he said the fault code dictates a mechancal fault not electrical ,could this be the egr valve ,iam going to use the info posted on here To take it off and clean it , any other info on the fault code would help before I take egr off.
 

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Discussion Starter #11
Hi guys I've been having trouble with my 156 2.4jtd20v with the mcf coming up with the orange engine light up on the dash , it's got no power when it comes up but when I take it to. A mate of mine who plus it in the the computer it's coming up with fault code p1235 . When he resets the engine fault the lights go out and the car is much better when you go over 2000 rpm , he said the fault code dictates a mechancal fault not electrical ,could this be the egr valve ,iam going to use the info posted on here To take it off and clean it , any other info on the fault code would help before I take egr off.
P1235 - usually indicates problem with Variable Geometry Turbo (either stuck VGT valve, or stuck VGT mechanism inside the turbo), that causes overboost and ECU goes to Safe Mod.

Look in the first and third post to find a solution :thumbs:
 

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P1235 - usually indicates problem with Variable Geometry Turbo (either stuck VGT valve, or stuck VGT mechanism inside the turbo), that causes overboost and ECU goes to Safe Mod.

Look in the first and third post to find a solution :thumbs:
ive read the 1st and 3rd :confused:post on the vgt valve , and the vgt mech , in the turbo , it looks to me that its not a diy job so is there anyone that can be recomendid to carry out the repair or if a new turbo is needed what sort of money am i looking at ?
 

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Hi guys I've had the egr valve cleaned out and it wasn't that bad and was working fine . All the pipe work (egr, turbo e,g ) checked and all ok waste gate and turbo looks ok , the problem looks like the maf is at fault because if you disconnect it , it makes no diff to the car and it does seem to be over fuelling ! So after picking up the car and talking to the garage doing the work ,and agreeing to get a new maf I drove the car up to about 4000rpm. And the mcf came up with the orange engine light .my question is that if the maf is at fault would that make the mcf come up?
 

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Hi guys I've had the egr valve cleaned out and it wasn't that bad and was working fine . All the pipe work (egr, turbo e,g ) checked and all ok waste gate and turbo looks ok , the problem looks like the maf is at fault because if you disconnect it , it makes no diff to the car and it does seem to be over fuelling ! So after picking up the car and talking to the garage doing the work ,and agreeing to get a new maf I drove the car up to about 4000rpm. And the mcf came up with the orange engine light .my question is that if the maf is at fault would that make the mcf come up?
have you had fault codes read ??????
 

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Discussion Starter #20
Hi guys I've had the egr valve cleaned out and it wasn't that bad and was working fine . All the pipe work (egr, turbo e,g ) checked and all ok waste gate and turbo looks ok , the problem looks like the maf is at fault because if you disconnect it , it makes no diff to the car and it does seem to be over fuelling ! So after picking up the car and talking to the garage doing the work ,and agreeing to get a new maf I drove the car up to about 4000rpm. And the mcf came up with the orange engine light .my question is that if the maf is at fault would that make the mcf come up?
These are not simptoms of bad EGR.

If MAF was faulty engine would run noticeably better when MAF is disconnected.


As I suggested, did you check VGT valve on the turbo (the rod on it should move freely in/out when pressed by fingers) ?

And it would be great to know all enviromental conditions when that error P1235 occured (most important is boost pressure, and maybe air flow mass, engine rpm...).
 
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