xc60 d5 engine systemservice required message
 

this has been covered elsewhere but thought I shollud post this one

car has 148000 and fully serviced.
suddenly after a little wet Hebridean weather -the message appeared upon start up. no problems until this message and there was no turbo acceleration.
I took it to our excellent local garage who listed out 9 faults, yet when mechanic started car message disappeared and car is as good as gold- 50 +mpg not 38 over same route. turbo is instant no smoke and excellent response.

Mechanic view is possibility of a 'common wire' water ingress (which he described dealing with on double insulated wires on' 68 plate vehicles', leading to 9 ,yes 9 sudden fault codes.all are fuel/exhaust sensor faults.car parked facing into an 80 mph southerly with rain.
I think that when I parked at garage, engine heat hot enough to dry out the water ingress. On the road the airflow through engine did not have this effect.
any thoughts?
codes were P010000
P054600
P067400
P229368
P02E168
P054400
P208464
P0100000
P0E4600
mostly 'general faults' some 'signal too high or out of range' an 'algorithm error'
CAR LAST SERVICE 3 MONTHS AGO NO FAULTS OR PROBLEMS UP UNTIL THIS MASS READING!!

This can happen sporadically, they're very sensitive beasts!
Mine does it if I fill up at one particular Sainsbury's fuel station, an extremely busy one, where my previous cars or my wifes car dont/havent had problems, and the car does not behave any different. Another member had this if he filled up at his local Tesco but not when using shell.
I had it happen last week on a very stormy day, but just the once.

It always clears after ignition off.
First time I scanned it it had a few codes related to MAF, but cleared them and none have recurred.

See how you go, does it reappear again in any regular circumstances, does it log any codes, etc...

Just run an obd11, no fualts some 150 miles and 2-3'cycles' later so hoping thats it -thanks for your advice-seems to be very sensitive beast but at 15ok i can forgive it!!

Fingers crossed!

well its all come baclk with a p01000 code, repeatedly- tried a maf cleaner but unconvinced and was right -ordered a replacement MAF sensor from autoparts Stornoway for £116- came in two days-great-turns out to be a genuine bosch part.

anyway to the point- I traced the wiring loom back to the y junction which is below where the MAF sits-and it disappears it the larger engine loom-no sign of a break- so removed the flexi coil protecting the wires and hey presto -broken and corroded sensor feed wire.
problem -only 1" of available wire from the main loom!

solution- I cut down one end and the clip of a scotch lock fitted it and glued the plastic shut-replaced plastic coil having filed end smooth.
10 yrs on and 150k I was still happy to replace the MAF, but worry that this is a chaffed and corroded wire within the loom and its factory protection.

Good find!
Fwiw, solder on a new length of wire, slide some heatshrink down over the join snd shrink it on, bind the whole joint to the loom to hold it tight and move any vibration upwards of the joint then sort out the other end. Use excess wire to make completing the job comfortable, and any excess can be overlapped and bound.

thanks Andy ,your absolutely right and have shrink cover ,wire etc.
I will be doing this as soon as I can. iwill slip something between wire and remaining wires to protect from soldering iron. its very restricted space so need to get it right-.by the way what do you recommend as a heat source- im concerned im so close to plastic and the engine loom- would foil be enough?
your help is much appreciated.
mike

Well done on finding the wire break.

A rag stuffed in there when soldering will help prevent damage to anything else.
A good hot soldering iron on a properly prepared joint and you only need to solder for 5 seconds.

As said above! Make sure Iron isnt too weedy and let it get fully up to temp. Dont contaminate the wire ends with mucky fingers. If poss shove the strands together/into one another and lightly pinch em together. Use a dab of plumbers flux on the bare ends to facilitate a good joint.

thankd swissxc90 and Andy (again) lol

both very useful comments,i'll try as soon as the wind dies down a bit- outer Hebrides very interesting in outside car repair terms!! Ive a new soldering iron and have the rest.