28D7 Fault Code - Alternator Communication

Post Reply
BMW Enthusiast
Posts: 2
Joined: 24 Mar 2017, 19:11
Car model: BMW 316ti Compact
Location: St Helens,Merseyside

28D7 Fault Code - Alternator Communication

Post by Demondriver » 24 Mar 2017, 19:39

Evening all

Bought a 316ti compact off my neighbour abit ago as a little project well got round to doing abit with it and plugged the Launch diagnostic kit into it tonight to investigate a few things and ive got 28D7 fault code which comes up as alternator communication... with a meter on the jump ports the power fluctuates from 14.08 (or around that) to 13.8 constantly which the power isn't too bad but with it fluctuating im assuming the alternator is on its way out which is causing the battery light to stay on constantly. Ive tried another big battery which I know is perfect as its being used on one of my other vehicles daily and its still the same so ruling out the battery being at fault. don't want to be spending on a new alternator if its a common wiring fault so thought would give it a try on here if anyone has had this before.

Few other codes ive got -
2850 - Variable valve gear guide sensor
27A4 EWS 3.3 Interface DMW - EWS

and then the front right wheel speed sensor needs looking at

any help greatly appreciated

BMW Enthusiast
Posts: 98
Joined: 12 Jun 2016, 23:05
Car model: 1998 318Ti (M52 323) Compact
1998 318is Coupe
Location: Hampshire, UK

Re: 28D7 Fault Code - Alternator Communication

Post by Beeverboy » 26 Mar 2017, 19:33

Most modern alternators have a smart charge system, suspect this is faulty causing the battery light.

Post Reply

Return to “Electrical”