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Discussion Starter #1
Hi All,

I wonder if anyone can offer suggestions to my rather ill timed problem..

On Friday I drove 300 miles to a friends wedding, no problems at all. Then, the following morning, after driving 500 yards, beep beep beep - motor control unit failure appears and I'm left with a car that feels like the turbo has left the county. She drove to the wedding and the following day completed the 300 mile trip home, but down on power and with no guts at all when hitting a hill.

After spending a few hours trawing this site and others, i'm confused as to the best course of action. This is where I'm after your help!

I have complete the ecu reset proceedure (or at least one of the many i found listed - disconnect battery for 45mins, turn on for 90s, turn off for 90s, start for 15m, off for 10m then drive). and this seemed to have a little effect but no where near back to normal. The engine light has stayed on and the console display still beeps and shows the warning.

Having read to try a new battery, clean / replace the MAF sensor, replace 1, 2 or 3 of the Lambda sensors, change the camshaft sensor, change the ??? and ??? sensors, replace the boost actuator (or something similar) I'm stuck with what to do next. Thing is, I'm pushed for time and cash as have my own wedding in 6 weeks and pretty much every weekend I need the car to make the round trip of 500 miles to where were having the wedding, so any quick, easy, preferably DIY routes of repair / diagnosis would be brilliant, so please send any ideas this way and fingers crossed it wont be the nightmare that it appears to be at the moment!

The car is a 2004 1.9 jtd 16v m-jet

Many thanks in advance,

Upex.
 

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simple this really - you have a reoccuring fualt!

if a fault occurs surround the induction or turbo system (and some other vital systems) on a JTD then it will stick the car into limp mode / get me home mode, whatever you wish to call it.

this means you will be limited to 3,000rpm or there abouts and the turbo wastegate will get left wide open and you will generate absolutely no boost pressure at all - to save any sort of damage to the engine.

I had to say driving 300 miles in limp home mode is less then recommended.

here is what you need to know about limp mode:

when the car detects a fault you may or may not see the engine management MCSF (motor control systems failure) error. more serious errors generate the light and beep beep MCSF. More serious still will put the car in limp mode as without doing so the engine would be at iminent risk of damage.

when the fault is detected limp mode is activated instantly for faults requiring limp mode. the fault is then also instantly stored in the ECU memory.

when you turn the car on you will see on the info centre the car does a systems check, it will then beep beep MCSF error flash up to show a STORED fault - this does NOT mean the fault has been detected again on this journey. if the fault has not been detected on this journey then the car will run as normal, i.e. not in limp mode.

long and short of which means that if you get the MCSF light come on, you shuld find a place to pull over, turn the vehicle off completely, wait 30 seconds and restart the vehicle. you will get the error message but the car should run normally.

if the car goes back into limp mode at an point in the journey you have a more serious fault that is constantly reoccuring, or the car has detected another more serious fault. only having the fault codes read will tell you exactly. when you read the fault codes it will tell you the engine parameters at the time the fault occured and how many times this fault has occured.

if the fault does not reoccur the engine management light will stay on for the next 6 journeys. if the fault does not reoccur within these 6 journeys the engine management light will go out and you will not get the error message any longer, however it will be stored in the memory for you to check.

what you need to know is the fault code you have.

you can do yourself some favours by having a check of your turbo piping, making sure there are no obvious splits in the pipes - black smoke out the back of the car is often a good sign of an air leak. also check the small vacuum pipes on the VNT actuator solenoid.

also check the connects on the MAF meter, VNT actuator solenoid and MAP sensor connections to make sure these are all as they should be. you can trace the wires back as far as you can through the loom, without taking it all apart, to see that there is no damage as well.

only way to truely know what is going on though is a fault code, it gives you a better starting point.
 

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Discussion Starter #3
artermis, many, many thanks for the detailed reply.

I will try to check these things myself, but although very capable of doing things, I dont know what or where they are. If you have any guidence or photos of the locations of these things, I would be very greatful as once i can place my hands on it, i can usually do it.

One thing that confuses me though, you say the limp mode will activate a rev limiter, however I havent had this happen at all. even when she was unable to maintain speed going uphill (fairly embarrasing) she was freely revving up as high as I wanted. the drive home was done at above motorway speeds for the large part, and no problems, just took longer to accelerate up to the speeds. Do you think this means that it is a 'less serious' issus so the car isnt calling on the limiter?

Hopefully the light will go off after the 6 journeys (have only made 1 since) and I may be inclinded to try and book into a garage then, because if its serious she'll have to live with it untill after the wedding, but that will involve at least 2000 more miles, which I totally agree, is not a good thing to do if all is not well.

Fingers crossed eh, what bad bl**dy timing!

thanks again artermis
 

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interesting......

I would find it very suprising if you have a complete lack of power yet are still running in 'normal' mode. 3krpm is fairly high for a diesel, I would give it a try see if she is truely revving all the way around to 5krpm.

things to check then.

if you are not in limp mode then I would also investigate the EGR valve, which is located on the back side of the inlet manifold. its a round black motor actuator on a metal valve body. if you follow the inlet top hose to the metal manifold its bolted onto the manifold where the hose meets the manifold. you can check the electical connection on that too but you need to have it off and make sure the valve is capable of moving inside it. you could also do with running an actuator test (software required) to make sure it is functioning.

I can;t post pics as at work wont allow access to photo bucket.

MAF sensor is on top of the airbox, follow the pipe up from the airbox, you can't really miss it, check connector on that.

MAP (manifold absolute pressure) or boost pressure sensor is the back of the manifold again further across than the EGR valve. its a tiny little unasuming thing with a little plug on top and two tiny bolts hold it on, check connector and clean it carefully.

the VNT solenoid is just to the left of the bonnet latch, as you look at it, on the slam panel / radiator. it has two pipes 1 coming in from the engine and one going out to the turbo, check these are not perished / split, although I doubt thats your problem, then check the connection on it as well.

it really is fishing around in the dark without the fault codes though and the lack of power does indicate you have a problem.
 

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good answers already here but you are realy only delaying getting the codes read, if you have a laptop (or borrow one) you just need a £10 lead and free software to read the code then you will KNOW more or less where the problem is :)

i think this http://www.ebay.co.uk/itm/USB-OBD-2...iagnostic_Tools_Equipment&hash=item2a1384437b is the rite cable, if its not i'm sure somone will correct me ;) or guy sells modded ones on here that will do more than just read you ECU codes (airbag ect)
 

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yeh that KKL cable would work
 

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Discussion Starter #7
Artermis, dickymint_156

Many thanks again, for the very detailed replies. Also, for taking the time to locate the cable i would need, interresting that it doesn't mention alfa, yet if you search for an alfa one there just more expensive.

I have ordered one, on your recommendation and will get the codes checked as soon as it turns up. I wounder where the plug is that it connects into though?

Artermis, I am 95% sure she is still revving to the red line, but will double check today and let you know.

Many thanks for all the help so gar, learned lots of new things already.

Thanks, upex
 

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Discussion Starter #8
error code reading - help!

Well I have the cable suggested avove, but do I need software? The one that came with it lists vw cars to choose from. How can I use this to offer any codes? Anyone any suggestions as need to get this sorted soon as my daily commute with this warning isn't good. So any help would be great. Thanks all, Upex
 

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Discussion Starter #9
All sorted. Was 2 spit turbo vac pipes. found and fixed and all power back! Now to fix the aircon!

Cheers for everyones help, Upex
 
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