CF80

[Acsills]

I took my 2013 X5 in for an oil change 2 weeks ago. The shop must have been very busy and the mechanic forgot to add the 2nd jug of oil. When I left, the engine light came on and I got a message saying engine oil critically low. I immediately took it back and he apologized profusely and added the 2nd jug. Since then the engine light has stayed on. I took it to a different place and it gave the code CF80. Could this be a result of the low oil or is this a coincidental fluke?

[X5Sport]

Hello and

The error code is nothing to do with the engine oil change. It indicates an issue with the transfer box (it’s on the back of the gearbox):

IMG_2628.jpeg (21.3 KiB) Viewed 422 times

Has the fluid been replaced as far as you know? BMW say it’s a lifetime system (which in reality is just three years) whereas the manufacturer (ZF) recommends all driveline fluids should be replaced at intervals of 8 years/50,000 miles - whichever comes first.

Have the errors been cleared? Unless they are then the warning light will remain on. Does the error log show the fault as ‘present’ (in which case it is still an issue). Any sign of jerkiness in gear changes or juddering on full lock at walking pace? If the latter then check you tyres are of the correct type (marked with a star on the sidewall as BMW Approved) and with less than 2mm tread difference between any tyre and the rest. You can’t fit cheap tyres to xDrive cars. Wrong tyres can (and have) broken transfer boxes or differentials. The warning signs are juddering and odd noises in the transmission.

In your case it would be wise to get the fluid changed, and clear the errors in the log to see if the error comes back, and also have the calibration checked to see if the transfer case is at ‘limit’ and needs resetting (done using ISTA software). Talk to a ZF Transmission specialist or BMW Main Dealer. Best case it’s just a fluid change and recalibration.