Wally86

Hello Guys,
I have Audi Q5 2010 TDI Diesel 2.0 L, I have owned it for two year's now with no major issues until now.

Whilst driving three weeks ago, I had a Alternator Failed to Charge Battery on my dashboard, so I installed a new alternator but it still won't charge my battery. I towed the car to the mechanic and they told me I had a faulty alternator, I explained to them that it's a new one. But they insisted it's faulty and I have to purchase a new. I got them to putting a another new alternator but now I was informed the battery has failed. So I gave them go ahead to installed a new Battery.

The car starts, however the alternator is not charging the battery. I'm speechless. I'm not sure what else to do. The alternator is only charging at 7v not enough to recharge the battery is what they told me.

Any suggestions please. I really appreciate all of the help.

nordicb

I stand corrected, but doesn't new battery need to be coded to the car? I haven't yet need to replace mine, but that's what forums say.

uncleiggy

Fairly recently my alternator died as well, usual stuff, battery would not charge and got all sorts of dash lights, luckily for me, the car literally died 2 blocks from my mechanic's shop. Upon inspection it turned out that the alternator was alright but the pulley was shot, it was an easy fix, no more than 30 mins and $200 in parts. Not sure if new alternators come with that pulley or not, if not then please check it as it could be the cause of your issues. Last but not least, my mechanic told me that when alternators fail there's a chance that the battery dies as well, it was not my case but worth to mention.

MP4.2+6.0

Given parts being thrown at it, scan it for codes and report back. If you have/had dash lights, you should also have codes. Those tell you a lot more. Not with a cheap OBDII generic scanner to be clear, which only deals with emissions and engine type systems. Something that can scan all Audi VW modules like VCDS or shop equivalents, including power management + CAN modules.

MurrayA4

On board with MP4.2+6.0's suggestion on how to proceed.If not you're likely to through many $$.

Wally86

Thanks for the great suggestion. I told the mechanic we need to code the battery, his answer was no need. We work on Audi cars all the time and never had to code them. But I personally believe it needs to be coded.

Bob Petruska

If you don't re-code the system for a new battery it will remember to old battery's state of health data and not the new battery.

A mechanic that says they never code an Audi battery is one I would probably walk away from quickly. All they need to do is use their "proper" Audi scanner tool and change the old battery serial number in the power management system by one digit to re-code/clear the power management system to get you back to a properly functioning PMS......