Hi guys, first things first, hi everyone ive joined this forum in the hope of finally resolving an issue with my stilo and after lots of research and money spent I am at the end of my teather hoping collective knowledge can help!

long story short purchased a 54 plate stilo 1.6 active sport 71k on clocks fsh a little while ago all seemed good however after a short while it started randomly cutting out locking up ive seen its very well documented on here.getting a mixture of immob alternator coolant temp errors I proceeded to investigate, checked all fuses and earths battery seemed ok 12.2v sat 14.1 running all earths under 0.5v loss came to check d4 upon this forums recommendations cleaned with contact cleaner still no avail. However I did notice under fuse tray there is another d4 style connector lying loose wrapped in cling film is this correct??

moved on to fault codes and got p0105 p0115 p1121 p1122 p0480 p0230 p0638 u1600 u1702and u 1700

most of these are circuit fails so my assumption was ecu so I purchased a tested recon with warranty installed every thing popped up no drama and was fine for 5 days today engine light came on with codes u1702 u1600 u1700 u1706 reset codes and was fine for 3 hours then popped up again. Im not sure and close to giving up so im hoping you guys can shed some light for me

thanks in advance

liam

14.1 V under running seems a but low to be honest. Was that at idle or under load? Check this example out about voltage and alternator, http://www.w8ji.com/battery_and_charging_system.htm

Check the voltage under load. Over 2500 rpm and see what the output is.

I can't shed more light on the U codes. I believe they are related to the can bus system.

Esaus said:

14.1 V under running seems a but low to be honest. Was that at idle or under load? Check this example out about voltage and alternator, http://www.w8ji.com/battery_and_charging_system.htm

Check the voltage under load. Over 2500 rpm and see what the output is.

I can't shed more light on the U codes. I believe they are related to the can bus system.

Click to expand...

And a battery with lower reading than 12.6 (ignition off) is worn out. It needs recharging or replacing.

The u codes came up as.
U1600 = key not recognised
U1700=NCM-NBC communication (motor-ecu<.>body computer no sign./plausibility)
U1702=NCM-NGE communication (motor-ecu<>el. steering*ecu) sign./plausibility)
U1706=NCM-NFR communication (motor*ecu<>ABS*ecu) no signal/plausibility

running test on newer battery with 12.69 sat and 14.2 cold idle.
car drove fine for 3 hours fine on 4th restart up pops engine light and those four codes again
no noticeable difference to car.

Wouldn't the car security not allow the car to be started if the key isn't recognized?

Check the D4 connector again and clean it well with electric cleaner and a toothbrush. I also had a loose connector in the box as you described. Look if it is corroded and allows signal to pass between the pins? I don't know what else to check out since you already replaced the ecu. Someone else on this forum might know more.

I would have thought the exact same buddy except the car starts and runs ok albeit with eml on, now don't get me wrong I'm not a mechanic so I don't know the ins and outs but I am a skilled engineer and have a pretty good knowledge to tackle most things but this is driving me mad. I've even tried both keys and still problem persists, one other thing I've noticed is that when I plug the code reader in the dash goes scatty saying loose connection over and over is this normal??

D4 was cleaned again when new battery was put in forgot to mention