Yet another CCCU problem?

Bargepower

A2OC Donor
So, after being parked for a couple of days, my money pit (aka 1.4 SE 2001) refused to unlock this morning.
It's had a replacement AF cccu as the old Q one used to kill the battery overnight by flashing the indicators every 30 seconds.
Car battery is good, starts first time every time, there's no water in the footwell or boot, but.....
The front doors won't unlock, none of the 4 electric windows are working, neither door mirror will respond, but the back doors and boot will lock and unlock.
When I got in using the key in the door lock I also noticed the date and time in the cluster had reset about 23 hours previously.
Car appears to know when it's been locked as the auto headlight coming home function is working.
Another CCCU required, do we think?
I'll scan with VCDS tomorrow afternoon, unfortunately work got in the way today.
Looking forward to getting its younger 1.6 brother next year ?
 
Not telling you to suck eggs, but have you checked the following..
All battery terminals including the auxiliary positive ones are nice and tight
Fuse on positive terminal tight and not corroded
Battery earth cable making good contact with the chassis by the rear left wheel and not corroded
The 2 fuses for the CCCU remove and check for burning in the fuse box then replace with new fuses
The CCCU is dry, all leads and connectors free from corrosion and locked in.

Some obvious, some not so.
 
All the above was checked yesterday. A scan with vcds at 06:00 reveals that the cccu doesn’t know the existence of the front doors.
 
remove the auto headlight switch. Confirm it's not the issue. Then check the cabling to the front doors - there are issues occasionally with corrosion on the contacts.

- Bret
 
Hi Ian,

This sounds to me like a wiring issue to the front doors rather than a CCCU issue.

Cheers,

Tom
 
Strange both front doors packed up at the same time whilst the car was parked, and reset the clock and calendar too.
 
Strange both front doors packed up at the same time whilst the car was parked, and reset the clock and calendar too.
Agreed, my explanation would be a strange coincidence.

The CCCU isn't able to reset the clock and calendar; that happens when the voltage to the instrument cluster drops below a given threshold.

It may be that the front door control modules have frozen. Their software is less stable than that in the rear door modules. Again, a voltage issue could have caused this. Have you tried disconnecting the battery for a while and then reconnecting it, such that the front door control modules reboot?

Cheers,

Tom
 
remove the auto headlight switch. Confirm it's not the issue. Then check the cabling to the front doors - there are issues occasionally with corrosion on the contacts.

- Bret
Already tried the headlight switch.
All connections are clean and dry to the doors.
I’ve got another cccu on the way, at least I can eliminate that as the cause or not.
And a spare is always handy!
 
Agreed, my explanation would be a strange coincidence.

The CCCU isn't able to reset the clock and calendar; that happens when the voltage to the instrument cluster drops below a given threshold.

It may be that the front door control modules have frozen. Their software is less stable than that in the rear door modules. Again, a voltage issue could have caused this. Have you tried disconnecting the battery for a while and then reconnecting it, such that the front door control module reboot?

Cheers,

Tom
Yes, tried that. No joy.
Battery is good, car started first time once I’d got in with the key.
Car had been stood over 24 hours when clock reset, going off the time and date showing then.
I’m looking forward to getting a nice reliable 1.6 fsi in March, won’t be anywhere near as much trouble.
 
Well, there we go.
Managed to borrow a CCCU from a customer at work. Fitted it, and using its supplied fob everything worked as it should.
Removed it and replaced it with my own and hey presto, back to all the problems.
So it’s definitely the CCCU.
AF’s mustn’t be totally bulletproof.
Glad I’ve got one one the way from our parts saviour @A2Steve.
 
Well, there we go.
Managed to borrow a CCCU from a customer at work. Fitted it, and using its supplied fob everything worked as it should.
Removed it and replaced it with my own and hey presto, back to all the problems.
So it’s definitely the CCCU.
AF’s mustn’t be totally bulletproof.
Glad I’ve got one one the way from our parts saviour @A2Steve.
Just to round this off.
AF CCCU arrived the other day from A2Steve. Fitted it today, recoded it to add my preferred features (fully locked beep on and one press to unlock drivers door, two to unlock everything off) and paired my keys. Working perfectly. Just to be sure I then fitted my old one back in the car, and sure enough everything went haywire again. So definitely beyond any doubt a broken AF CCCU.
 
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