W203 Battery Alternator visit workshop message

Ask for and share advice on using the PicoScope kit to fix vehicles here.
Post Reply
victor2k
TwoWaves
TwoWaves
Posts: 337
Joined: Thu Jan 28, 2016 7:17 am

W203 Battery Alternator visit workshop message

Post by victor2k »

Hello,
I need some help to diagnose a Mercedes W203 what show on MFD "Battery Alternator Visit Workshop".
The charging voltage is 14,5-14,7v at idle,the wiring was checked between alternator and Front SAM.
No faults related to charging system was stored.
Regards.

User avatar
STC
Banned
Posts: 790
Joined: Sun Sep 13, 2015 2:10 am

Re: W203 Battery Alternator visit workshop message

Post by STC »

Victor

No faults stored, thats unusual, what scanner are you using and where are you looking ??
Some history please, has this had an alternator fitted recently ?

Have Engine Earth and Alternator B+ been Volt Dropped, with alternator fully loaded ?

Could you probe the 2 small alternator wires from Ign off, ign on,cranking and idling then post the file.

thanks

victor2k
TwoWaves
TwoWaves
Posts: 337
Joined: Thu Jan 28, 2016 7:17 am

Re: W203 Battery Alternator visit workshop message

Post by victor2k »

Hello,
I used Star but the readed faults isn't related to the charging...some bulbs and other stuffs .
The alternator wasn't changed,I checked the wires and no abnormal voltage drop on B+
On MB forum I read about the changing of alternator...what I can check before replace it?
Thank you.

User avatar
STC
Banned
Posts: 790
Joined: Sun Sep 13, 2015 2:10 am

Re: W203 Battery Alternator visit workshop message

Post by STC »

Using STAR I am surprised you dont have a faultcode - tied in with a Message on the Cluster - never seen that before.
Actual Values in Cluster ????

Have seen shorted / broken wires, wrong alternators, faulty regulators, SAM but always a fault code.

Are you doing a Short Test or just looking in one control unit ?

Scope the Peak to Peak and Current from the alternator get some additional clarity.
You can buy the Regulator Seperately.

What is Star Guided telling you to do and look for ???

Post Reply