typhoon43

My E55 has the Red 'Visit Workshop' light come on every time I start the car. I've done some digging and already have the voltage regulator and brand new AGM front battery ready to go in my garage, but I wanted to see what the car says. I purchased a Bluetooth adapter and an app for my phone, which did show my idling voltage at 13.2, and engine off voltage at 11.3. The only thing that bothers me is that I went to the code reading section of the app and it shows that I have no codes. Soooo, either the app is janky, or the ECM doesn't actually store a fault code for whatever happens to be throwing me this red ring of death every time I start my car. Any insight? Should I have a code stored? Car drives great otherwise.

Thanks!

03'55AMG

The generic bluetooth obd2 adapters will usually only pick up check engine light codes, nothing else. To see the trouble code for your issue, STAR Diagnostics would be needed

typhoon43

Thanks for the quick reply. Hmm, I think it's time I start shopping for a STAR/DAS setup.

03'55AMG

Contact Shardul on here. He has complete every-single-thing-you-need setups for great prices. And he's a member who you can trust if you need help/support.

typhoon43

I already have a list of stuff to buy from Shardul and Chawkins . I just promised myself I wouldn't buy anything for the car until I sold the G8. Hopefully he's gone soon. Going to do the front battery for giggles since it's still the original from 05', and if that doesn't clear it, I'll do the voltage regulator on the back of the alt. It's not like it could hurt, and if the code is still there I can at least narrow it down since I'll have new pieces installed already.

typhoon43

Well I checked the front battery and it was the original. After pulling it it was only showing 7.5 volts and my charger reported it was bad (no, really? Lol!) I put a brand new AGM battery that I had pre-charged, turned the car over, and no more red workshop indicator. Woot! Still noticed at idle that the interior overhead lights fluctuate a bit, so I may swap the voltage regulator on the back of the alternator anyways. I have a new one, and the rear battery is brand new, so that should clean it up since when I'm driving I see 14 volts, which tells me the alternator can still bring it. So far, so good. 3 weeks in with the car and I'm loving her more every day. These forums have really taken the fear out of working on this thing. Thanks gang.

03'55AMG

Yea, that's def. your voltage regulator. When mine went bad, the lights dimmed at idle, idle was rough, and never had convenience functions. New battery and regulator at same and it was all solved. Then my battery would die every night to the point where the car wouldn't wake up upon opening a door, but that turned out to be the audio gateway; it was drawing over 4 amps when the CAN BUS was asleep.

typhoon43

Thanks for the confirmation man. I'll get that regulator in ASAP.