Battery Drain

Vic said:
You can do the same test with fuse box to identify power loses. Remove fuse, connect multimeter in its place. Do this with all the fuses.
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I've currently got a battery drain issue.

Can someone explain this fuse testing process please? I've only got a basic multimeter, so can't do the inline tests that some people seem to be doing for this.
 
Grumple said:
I've currently got a battery drain issue.

Can someone explain this fuse testing process please? I've only got a basic multimeter, so can't do the inline tests that some people seem to be doing for this.
Click to expand...
Take a pic of your meter, so we know what you can measure please.
Mac.
 
Hi Mac, it's just a basic multimeter with probes - I did manage to rig up a kind of in-line test (see below!), and that read 12.5:

20221204_122358.jpg


I went through the fuse testing process, and found that these fuses are drawing power with the ignition off:

36 = 12.2
37 = 10.4 (went from 1 up to this over 5 mins)
41 = 8.2

So I'm guessing it's a CCU issue as per most other posts regarding battery drain? No power to the windows after 10 minutes as per a previous comment though...

What's my best option for replacing/fixing the CCU?

Thanks!
 
Grumple said:
Hi Mac, it's just a basic multimeter with probes - I did manage to rig up a kind of in-line test (see below!), and that read 12.5:

View attachment 101979

I went through the fuse testing process, and found that these fuses are drawing power with the ignition off:

36 = 12.2
37 = 10.4 (went from 1 up to this over 5 mins)
41 = 8.2

So I'm guessing it's a CCU issue as per most other posts regarding battery drain? No power to the windows after 10 minutes as per a previous comment though...

What's my best option for replacing/fixing the CCU?

Thanks!
Click to expand...
Are the numbers above volts or amps, and were the meter probes across the contact each side of the fuse you removed, or somewhere else?
We'll get there 👍
Mac.
 
PlasticMac said:
Are the numbers above volts or amps, and were the meter probes across the contact each side of the fuse you removed, or somewhere else?
We'll get there 👍
Mac.
Click to expand...
Thanks Mac, 20v setting on the multimeter and went through each fuse putting the probes in their place one at a time.

Those results seem to mirror other posts that lead to CCUs being replaced.
 
I gave up on this over the Xmas period and have just been disconnecting the battery in between drives!

I had some input from Timmus before Xmas and he's not convinced it's the CCU as it's a more reliable model, so I guess I have to investigate more.

If I set the multimeter to the 10A option, can I then use it in-line between the negative terminal and lead to find out which fuses make a difference?
 
Sorry for necroposting and stealing the thread but I'm struggling with the same issue.

Initially I also (on top of battery drain) had a problem of the central locking and electric windows not working whenever it was cold so I suspected the CCCU and took it to an expert who replaced all the relays and checked that there were no other issues with the board. After this was done, central locking and windows started working but oddly enough only after driving for some time plus the battery drain was still there.

I can hear a clicking noise coming from the CCCU so the relay going on and off is definitely what's killing the battery but interestingly, the clicking noise stops if I remove fuse no 42 and then put it back. The fuse is the second one for central locking which has led me to believe there must be something going on in the central locking system confusing the CCCU. Maybe a door microswitch?
 
Once again the FIRST thing needed is a USEFUL scan i.e. VCDS as that lists what the car thinks is wrong and from that we can guide you rather than just play parts cannon and still be no further forward.
 
Sorry, forgot to mention that I have run a scan but it didn't reveal much:

01330 - Central Control Module for Central Convenience (J393)
53-10 - Supply Voltage Too Low - Intermittent

And then after that a number of modules that show No Communications but I believe all these are just from the battery draining out completely.
 
I just went outside to check and nothing, no fault codes found although I can hear the clicking from the CCCU.

If the CCCU was still bad should it definitely show up as a fault code?
 
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