ECU and battery Problems

[limoncello]

The ECU managemnt warning light comes on quite often when i start the car or leave it on but not running the engine for a minute or so, sometimes it turns a few things

The battery meter is down to 10%, Several times it went back to 100% but goes back down if i use any electrics without the engine running.

I thought the battery may be old and have booked it in for a new one, however Im now unsure that it is the battery. I tested it today with a multimeter and found that it was at 12.6V turned the ignition to on for a minute , UCU warning came up, retested the battery still the same.

unlike others not once has the car failed to start or even had a problem starting. it seems to me the power is there but the computer doesnt think so.

If the battery Regulator is at fault it wouldnt charge the battery and the voltage would be drained.

where is the problem, is it likely to still be a battery problem?

[Conan_the_Librarian]

What codes is VagCom showing if any?

[Mkoneman]

yeah bring up measuring blocks in the engine controller and watch the battery voltage

[limoncello]

Thanks for the quick responce

Vag com is showing these to do with the batt regulator, these have been there before long before the ecu warnings though

-------------------------------------------------------------------------------
Address 61: Battery Regul. Labels: 4E0-910-181.lbl
Part No SW: 4E0 910 181 C HW: 4E0 915 181 C
Component: ENERGIEMANAGER H11 0340
Revision: 00000000 Serial number: 00000000003460
Shop #: WSC 00847 210 56212
VCID: 204A67C68AB1

Part No: 4E0 915 105 A
Component: von VA0 390830U0EZ
Coding: 34453039313531303541205641303339303833305530455A
Shop #: WSC 00468 210 67755

5 Faults Found:
02273 - Quiescent Current Stage 2
000 - - - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 7
Fault Frequency: 8
Mileage: 136992 km
Time Indication: 0
Date: 2010.08.27
Time: 18:43:55

02276 - Quiescent Current Stage 5
000 - - - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 7
Fault Frequency: 7
Mileage: 136992 km
Time Indication: 0
Date: 2010.08.27
Time: 18:44:04

02274 - Quiescent Current Stage 3
000 - - - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 7
Fault Frequency: 7
Mileage: 136992 km
Time Indication: 0
Date: 2010.08.27
Time: 18:44:14

02277 - Quiescent Current Stage 6
000 - - - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 7
Fault Frequency: 7
Mileage: 136992 km
Time Indication: 0
Date: 2010.08.27
Time: 18:44:24

02272 - Quiescent Current Stage 1
000 - - - Intermittent
Freeze Frame:
Fault Status: 00100000
Fault Priority: 7
Fault Frequency: 2
Mileage: 137177 km
Time Indication: 0
Date: 2010.09.08
Time: 14:13:36


Im new to VAGCOM so didnt know about the measuring blocks in the engine controller, i will look it up and get the results

[limoncello]

just had a look at vag com, im not sure what the relevant fields to use are, any specific instruction to measure voltage

[Conan_the_Librarian]

When the engine is running just cycle through the measuring blocks until you find voltage readout.

[limoncello]

Ok have done that

From the Batt reg
Group A: '003
Battery Condition Internal Battery Qv
TIME Resistance (Battery Aging)
STAMP % ohms Ah
0.2 10 4 90
0.49 10 4 90
0.77 10 4 90


Group B: '004
Current Value Static-Current Total Energ Total Energy
TIME from Battery Mean Value Balance Throuput
STAMP A Ah Ah
0.06 13 0 9811 1162
0.34 4.1 0 9811 1162
0.62 9.1 0 9811 1162
0.9 12.8 0 9811 1162
1.21 3.6 0 9811 1162
1.47 10.2 0 9811 1162
1.77 12 0 9811 1162
2.03 12 0 9811 1162

from engine

Group A: '030
Voltage Voltage Bin. Bits Duty Cycle
TIME
STAMP V V %
0.13 0.74 0.36 0 01 1
0.63 0.74 0.36 0 01 1


is this the sort of thing

[limoncello]

Did a few more, but just logged it rather than logging it working, the last post is unclear with all the text joined together

--------------------------------------------------------------------------


Address 01: Engine (4E0 910 401 J)

19:13:44 Group 030
0.740 V Voltage
0.360 V Voltage
0 01 Bin. Bits
1.0 % Duty Cycle

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Address 61: Battery Regul. (4E0 910 181 C)

19:19:30 Group 003: Battery Status I
10.0 % Battery Condition
4 ohms Internal Battery Resistance
90 Ah Qv (Battery Aging)
N/A

19:19:30 Group 006: Last Standing Time && Last Driving Cycle II
1.0 Duration last Standing Time
1.00 Energy Balance of last Drive
100.0 % Battery State of Charge (SOC)
N/A
Friday,01,October,2010,19:19:38:43017
VCDS Version: Release 10.6.1
Data version: 20100831


Address 61: Battery Regul. (4E0 910 181 C)

19:19:36 Group 003: Battery Status I
10.0 % Battery Condition
4 ohms Internal Battery Resistance
90 Ah Qv (Battery Aging)
N/A

19:19:36 Group 006: Last Standing Time && Last Driving Cycle II
1.0 Duration last Standing Time
1.00 Energy Balance of last Drive
100.0 % Battery State of Charge (SOC)
N/A
Friday,01,October,2010,19:20:35:43017
VCDS Version: Release 10.6.1
Data version: 20100831


Address 61: Battery Regul. (4E0 910 181 C)

19:20:34 Group 003: Battery Status I
10.0 % Battery Condition
4 ohms Internal Battery Resistance
90 Ah Qv (Battery Aging)
N/A

19:20:34 Group 001: General
14.30 V Generator Voltage (specified)
14.00 V Battery Voltage (actual)
29.0 % Dynamic-Field Signal
0.00 s Load Response Time


its while running, so it appears battery condition is at 10% 9which corresponds to the MMI meter), but the actual batt votage is 14V

[Conan_the_Librarian]

If you put a volt meter across the battery when running it will just show alternator voltage which should be near 14V. measure the battery voltage when you park up for the evening and again in the morning a drop of more than half a volt would indicate that the battery is on the way out or there is an earth somewhere.

[PsYcHe]

Has the car been jump started recently? Your post suggests otherwise, but that's a common cause for killing the battery ECU.

Or the car has decided it doesn't like the battery anymore. There's a post somewhere here or on the ross-tech wiki on how to tell the D3 it has a new battery and see how that behaves.