mcs

Hi all,

I have been having a strange issue with my 04 A8.

Basically, the car thinks the battery is at 10%. I know this is a common issue, but I have had the car for 18 months now and its only just happening.

Things I have done differently:
I have enabled the hidden menu and turned on the battery meter;
I have retrofitted rain/light sensor (the rain sensor works perfectly, but the light in auto mode throws the light sensor error. I feel this is due to the roof module having coding for just a light sensor not rain/light sensor)

I had to shift the battery slightly to get at the motor that soft closes the trunk. I didn't disconnect the battery, but there was a small wire coming from the loom to the + terminal that had to be undone to shift the battery enough to get that motor out.

It seemed the first time the battery said 10%, I could turn the radio off before the car shut off, and the next time I drove the car the battery would pick up charge very quickly. ie, back to 100% within 6klm.

Will changing the serial number of the battery in VCDS fix this issue?

Mike

jakematic

Coding the battery, even by changing the last digit, should correct the 10% issue.
Assuming it is a similar battery and is not dying due to age or bad cells.
This presumes you actually changed the battery - which is the reason to do the coding.

Many argue till the cows come home that it's not required.
Maybe it will adjust itself over time, but Art over in engineering designed it this way so my advice is to follow the correct factory procedure.

Did you reconnect said small wire ?

Why is the 38 module not coded properly ?
Post up an full Autoscan and we can take a look.

mcs

Thanks for the reply.

Yes I reconnected the small wire. I assume the battery is fine as it is quite young, the correct Audi battery and if its charge can get back to 100% in 6klms it isn't the battery. I haven't had any issue starting the car, and any electrics work properly apart from the ones turned off by the battery computer.

I believe the roof module was coded incorrectly to have a light sensor but I cant be sure until it is recoded by the dealer. I do not have VCDS, I have been trying to get one here but I am not paying $600 for it.

The car originally did not come with either a rain/light or a light sensor. I retrofitted the rain/light sensor and had it coded in the central electronics module as per factory requirements (rain/light is coded in the central electronics, and the light only sensor is coded in the roof module)

I will try and get a copy of the scan when it goes in.

Mike

jakematic

Holy cow!
Is that due to VAT ?

mcs

Pretty much. Everything is relatively expensive here. Low population and high demand.
(Australia)

jakematic

Aha! My apologies.... I couldn't remember where you were.

Perhaps one of the nice folks here could send you one at non Oz prices....

ltooz_a6_a8_q7

She's about 20 miles from me and she likes to visit me instead of having it herself to reset codes. If you want one just to get the codes and reset codes, I'll send it to you. I paid $30 for it.

Cheers,

Louis