S3 (52 plate) Current Drain

S3Robin · 04-09-2008, 09:16 PM

I have had an Audi S3 (52 plate) since new but since moving to the Isle Of Man have started to experience problems with a periodic flat battery if I leave the car for 2 weeks or so without driving it. It is fair to say that the longest journey I do over here is only about 30 minutes duration so the battery doesn't get the charging time that it used to in the UK, but nobody else seems to be experiencing this problem over here. I have had the car into several garages who can find no fault. The battery was replaced a few months but now I have the same problem again. I tried checking the current draw on each fuse to see if I could detect any obvious problem. Some circuits registered a small current but this is to be expected to run the electronics in standby, alarm etc.

Has anyone else experienced anything similar or can give me any advice as to what current I should expect to see drawn on each circuit, for comparison purposes.
The fuse circuits which registered non-zero currents with the car standing idle were as follows:

(fuse#)
12 - Onboard diagnosis, reading lights, alarm 355mA (all lights off when meas. taken)
15 - Instrument Cluster, Central locking 10mA
16 - Magnetic Clutch / Water Pump 128 micro amps
17 - Heated door locks 55 micro amps
28 - Fuel pump 1.2mA
30 - Sunroof 48mA
32 - Engine Management 0.5mA
37 - Radio 4mA
48 - Luggage Compartment 38mA

Cheers,

Robin

craigyb · 05-09-2008, 06:19 AM

355mA is a 1/3 of an amp, that will drain a battery easily enough.

PetrolDave · 05-09-2008, 07:52 AM

Quote:

Originally Posted by S3Robin

(fuse#)
12 - Onboard diagnosis, reading lights, alarm 355mA (all lights off when meas. taken)

That's about 20 times what it should be.

Have you checked for fault codes with VAG-COM?

S3Robin · 06-09-2008, 11:54 AM

Dave,
I suspect that measuring the current drawn by each fuse was not the best approach and that I should have started by measuring the total battery current. To measure each fuse requires having the driver's door open and then holding-in the door-close sensor and locking the car to arm the alarm etc. The car is currently with an auto electrician who can find no fault and reckons the current drain is normal. I think VAG COM may be next port of call. I don't have one at present but there seem to be plenty on Ebay (cable and basic fault code reading software) for about £15. I noted another post on here where the alarm circuit was causing the battery to drain. The problem is there are no Audi dealers on the island so no real expertise.

Thanks for the advice.

Cheers, R

PetrolDave · 14-09-2008, 03:41 PM

Quote:

Originally Posted by S3Robin

The car is currently with an auto electrician who can find no fault and reckons the current drain is normal.

What does he say the current drain is? If his figure is also in the region of 350mA then there is no way that is normal.

Tame Technician · 20-10-2008, 06:25 PM

Instrument pack. Drain should go away when fuse 15 removed.

Common as muck.

PetrolDave · 20-10-2008, 06:33 PM

Quote:

Originally Posted by Tame Technician

Instrument pack.

If the instrument pack takes 350mA then it's cream cracked - that sort of current drain will flatten a car battery in a few hours never mind days.

Tame Technician · 20-10-2008, 06:42 PM

Thats what I mean, the Instrument pack in F**k*d and causing the drain. I've done loads for that fault. Removing the fuse will show for sure. Make sure it is fuse 15 though, i was just going by the description posted. Could be a different fuse for the combi- processor inside the pack itself.

S3Robin · 02-12-2008, 02:51 PM

Okay, I am now about £200 worse off through various so called mechanics 'having a go' and finding nothing but the problem still remains. One even had the cheek to tell me that the problem was that I am not driving it often enough and thay any car left for 2 weeks will get a flat battery (!). I do however have some fault codes which seem to suggest that I may have been on the right lines with my original diagnosis.

Fault codes are:
0991 - Cabin Light Short with Power
01134 - Alarm Horn - H12 No Communication, Intermittent

Last time the battery went flat the fault code pointed to the central locking (he didn't tell me the eaxct code); he cleared the fault code and it hasn't come back so this may have been caused by the battery cycling (?)

I don't know what fuses these faults relate to. DTC 0991 sounds like maybe fuse 12? If anyone has had any experience of these fault codes and which fuses they relate to, my next step is to charge the battery, remove this fuse and see if goes flat again. Grateful for any tips or advice.

Cheers,

R

04-09-2008, 09:16 PM	#1 (permalink)
S3Robin Citroen C1 GT Join Date: May 2002 Location: Isle of Man Posts: 100	S3 (52 plate) Gradual Battery Drain I have had an Audi S3 (52 plate) since new but since moving to the Isle Of Man have started to experience problems with a periodic flat battery if I leave the car for 2 weeks or so without driving it. It is fair to say that the longest journey I do over here is only about 30 minutes duration so the battery doesn't get the charging time that it used to in the UK, but nobody else seems to be experiencing this problem over here. I have had the car into several garages who can find no fault. The battery was replaced a few months but now I have the same problem again. I tried checking the current draw on each fuse to see if I could detect any obvious problem. Some circuits registered a small current but this is to be expected to run the electronics in standby, alarm etc. Has anyone else experienced anything similar or can give me any advice as to what current I should expect to see drawn on each circuit, for comparison purposes. The fuse circuits which registered non-zero currents with the car standing idle were as follows: (fuse#) 12 - Onboard diagnosis, reading lights, alarm 355mA (all lights off when meas. taken) 15 - Instrument Cluster, Central locking 10mA 16 - Magnetic Clutch / Water Pump 128 micro amps 17 - Heated door locks 55 micro amps 28 - Fuel pump 1.2mA 30 - Sunroof 48mA 32 - Engine Management 0.5mA 37 - Radio 4mA 48 - Luggage Compartment 38mA Cheers, Robin __________________ ...So little time, so many hurdles to jump.... Last edited by S3Robin; 04-09-2008 at 09:22 PM.

05-09-2008, 06:19 AM	#2 (permalink)
craigyb Nissan GTR Join Date: Aug 2004 Location: Manchester Posts: 3,687	355mA is a 1/3 of an amp, that will drain a battery easily enough. __________________ My Retrofit Website

06-09-2008, 11:54 AM	#4 (permalink)
S3Robin Citroen C1 GT Join Date: May 2002 Location: Isle of Man Posts: 100	Dave, I suspect that measuring the current drawn by each fuse was not the best approach and that I should have started by measuring the total battery current. To measure each fuse requires having the driver's door open and then holding-in the door-close sensor and locking the car to arm the alarm etc. The car is currently with an auto electrician who can find no fault and reckons the current drain is normal. I think VAG COM may be next port of call. I don't have one at present but there seem to be plenty on Ebay (cable and basic fault code reading software) for about £15. I noted another post on here where the alarm circuit was causing the battery to drain. The problem is there are no Audi dealers on the island so no real expertise. Thanks for the advice. Cheers, R __________________ ...So little time, so many hurdles to jump....

02-12-2008, 02:51 PM	#9 (permalink)
S3Robin Citroen C1 GT Join Date: May 2002 Location: Isle of Man Posts: 100	Okay, I am now about £200 worse off through various so called mechanics 'having a go' and finding nothing but the problem still remains. One even had the cheek to tell me that the problem was that I am not driving it often enough and thay any car left for 2 weeks will get a flat battery (!). I do however have some fault codes which seem to suggest that I may have been on the right lines with my original diagnosis. Fault codes are: 0991 - Cabin Light Short with Power 01134 - Alarm Horn - H12 No Communication, Intermittent Last time the battery went flat the fault code pointed to the central locking (he didn't tell me the eaxct code); he cleared the fault code and it hasn't come back so this may have been caused by the battery cycling (?) I don't know what fuses these faults relate to. DTC 0991 sounds like maybe fuse 12? If anyone has had any experience of these fault codes and which fuses they relate to, my next step is to charge the battery, remove this fuse and see if goes flat again. Grateful for any tips or advice. Cheers, R __________________ ...So little time, so many hurdles to jump....

20-10-2008, 06:25 PM	#6 (permalink)
Tame Technician Shank's Pony Join Date: Aug 2008 Location: Suffolk Posts: 12	Instrument pack. Drain should go away when fuse 15 removed. Common as muck.

20-10-2008, 06:42 PM	#8 (permalink)
Tame Technician Shank's Pony Join Date: Aug 2008 Location: Suffolk Posts: 12	Thats what I mean, the Instrument pack in F*kd and causing the drain. I've done loads for that fault. Removing the fuse will show for sure. Make sure it is fuse 15 though, i was just going by the description posted. Could be a different fuse for the combi- processor inside the pack itself.