Gremlins!

dan_b

dan_b

A2OC Donor
Ok, let's connect the symptoms...

Intermittent failure to lock/unlock the car with the remote key fob.
Sometimes you hear the doors de-lock when the key goes to position 2 in the ignition
Intermittent failure of the off-side rear electric window to move back up to closed - the one-shot up function doesn't work, and sometimes it'll go up a few cm, then down, then up, then down...
Opening the driver's door only switches on the front interior lights, not the rears.
In fact the rear interior lights don't seem to come on at all when you use the rear light switch.

Is this a CCCU failure, or a door microswitch/door control module failure?
 
Key fob battery; faulty courtesy lamp unit? I had a couple of those symptoms and replacement of battery and lamp unit solved the problems. Good luck getting it sorted :)
 
Scan Dan?

Could be a number of things playing up here - Do you know if you've got the "Q" cccu, have you checked the bulb in the rear light unit and have you cleaned the o/s/r window and frame?
Does the same issue with the window occur from the drivers control and the o/s/r window control?

Cheers

Jeff
 
dan_b said:
Ok, let's connect the symptoms...

Intermittent failure to lock/unlock the car with the remote key fob.
Sometimes you hear the doors de-lock when the key goes to position 2 in the ignition
Intermittent failure of the off-side rear electric window to move back up to closed - the one-shot up function doesn't work, and sometimes it'll go up a few cm, then down, then up, then down...
Opening the driver's door only switches on the front interior lights, not the rears.
In fact the rear interior lights don't seem to come on at all when you use the rear light switch.

Is this a CCCU failure, or a door microswitch/door control module failure?
Click to expand...

It sounds very much like a CCCU on the blink, there are too many separate faults to be individual problems (all controlled by the CCCU) that just happened to coincidentally go wrong all at the same time.

Perhaps a temporary swap of CCU to see if that makes any difference?
If you were to meet up with a friendly A2 owner locally sometime? (Tonight?) the swap might help point to the cause?

Steve B
 
- Scan Dan? - no!
- Do you know if you've got the "Q" cccu, - no!
- have you checked the bulb in the rear light unit - not yet!
and have you cleaned the o/s/r window and frame? - no!
Does the same issue with the window occur from the drivers control and the o/s/r window control? - but , just to be different, yes!

Cheers :)
 
Hi Steve
If you're free this afternoon/early evening I could definitely pop in on my way home.

Birchall said:
It sounds very much like a CCCU on the blink, there are too many separate faults to be individual problems (all controlled by the CCCU) that just happened to coincidentally go wrong all at the same time.

Perhaps a temporary swap of CCU to see if that makes any difference?
If you were to meet up with a friendly A2 owner locally sometime? (Tonight?) the swap might help point to the cause?

Steve B
Click to expand...
 
dan_b said:
Hi Steve
If you're free this afternoon/early evening I could definitely pop in on my way home.
Click to expand...

Hi I am around all afternoon and early evening.

Do you have VCDS, because if not I can scan it for you and we can narrow down the causes.

Steve B
 
This is the CCCU. I have a similar fault. No auto up on my drivers window door lock automatically activate without cause and my internal lights flicker when on and engine off.
 
I share the finicky electric window fault, driver's only and intermittent. That's the only fault so I was presuming window regulator. Disappointing. So much for cheap motoring! ;)
 
I seem to have a similar problem, albeit not as severe as Dan's. My rear interior lights (bulbs both fine BTW) will not come on with any door open. They do come on if the front switch is in "All on" position.
I seem to have had various other annoying electrical faults, ie no door open on the DIS with rear pax door open, (new door lock so M/S is fine) and bizarre operation of the front windows.
It would seem to point to the CCU being on the way out. hey ho.

What results would one expect to see on a scan of the CCCU?
 
Ok I popped round Steve's house last night and we did some probing.

My CCCU is not the dreaded Q version, it's an AE/AF? Is this one also known to die?
The nearside rear door lock has completely stopped working and so doesn't actually lock when the central locking is enabled.
The offside rear door lock is often failing to de-safe correctly.
All doors all show as open correctly on the DIS.
The rear interior bulbs and switch are ok (we swapped an entire unit over). The rear interior lights only come on when the front light switch unit is put in to "1".
 

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Hi Dan,

I suspect your car has multiple simultaneous problems.

I'm yet to get to the bottom of the issue with the rear interior light. I have observed this electrical niggle on countless A2s, though I haven't yet had a chance to investigate it and find the exact cause. I've also seen various degrees of severity; sometimes the functioning of the rear light simply 'freezes' and can be made to work properly again (at least for a while) by simply switching it on and off manually, whereas other times it stops functioning entirely and cannot be simply coerced into working again. The A2 belonging to a friend of mine (non club member) has this issue, so I shall endeavour to fix it when I get a chance and let you all know the cause.

Dan, if I remember correctly from when I did your rear electric window upgrade, you've got the AF CCCU. Along with the AE unit, this is the most reliable revision. That said, Terry's AF-type CCCU died, so they're not bulletproof.

The cycling of the locks when you turn the key in the ignition barrel is a clear indication of either microswitch failure or failure of the microswitch's signal to reach the CCCU (possibly due to a confused door control module, bad loom connection, etc).

If the 'door open/closed' signal is reaching the DIS display from the nearside lock, then I'd suggest that the door control module is doing its job properly and that the failure of that door to lock is down to the lock itself. The common 'won't de-safe' fault on the opposite side is almost invariably caused by the lock itself. Whilst the jury is still out regarding the rear interior light issue, I doubt that the CCCU is the cause of the faults. Indeed, with multiple rear door lock faults, it could be that the rear light logic is just seriously confused.

I've lost count of the number of central locking systems I've fixed and would happily solve your car's troubles too - unfortunately, we live 250 miles apart, but don't let that put you off! :)

Cheers,

Tom
 
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Mustang-owner said:
Point 1. At £250 this is an expensive fix
Click to expand...

Agreed; a return journey to mine from Land's End would still work out cheaper!

Mustang-owner said:
Point 2. If the 2nd picture in the listing is of this persons work, I wouldn't let them anywhere near my car (see below)
Click to expand...

I think this is his demonstration of water-damaged wiring/connectors. Quite why he chooses to show this as a means of promoting his services, I'm not too sure.
 
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Hi Tom
Thanks for your excellent post. So do you think I have possibly two unrelated faults with both rear doors, which together are confounding the CCCU to cause the interior light fault? Possibly a seized lock on the nearside rear door, and a dodgy microswitch in the offside?
 
dan_b said:
Hi Tom
Thanks for your excellent post. So do you think I have possibly two unrelated faults with both rear doors, which together are confounding the CCCU to cause the interior light fault? Possibly a seized lock on the nearside rear door, and a dodgy microswitch in the offside?
Click to expand...

No worries, Dan. :)

Yes, that's my current thinking. Obviously I'm doing this diagnosis with nothing more than your descriptions to work with, but you've summarised my suspicions correctly.

Tom
 
timmus said:
Hi Dan,

I'm yet to get to the bottom of the issue with the rear interior light. I have observed this electrical niggle on countless A2s, though I haven't yet had a chance to investigate it and find the exact cause. I've also seen various degrees of severity; sometimes the functioning of the rear light simply 'freezes' and can be made to work properly again (at least for a while) by simply switching it on and off manually, whereas other times it stops functioning entirely and cannot be simply coerced into working again. The A2 belonging to a friend of mine (non club member) has this issue, so I shall endeavour to fix it when I get a chance and let you all know the cause.
Click to expand...

You are welcome to test out your theory on mine also Tom ;)

Andrew
 
simufly said:
I seem to have a similar problem, albeit not as severe as Dan's. My rear interior lights (bulbs both fine BTW) will not come on with any door open. They do come on if the front switch is in "All on" position.
I seem to have had various other annoying electrical faults, ie no door open on the DIS with rear pax door open, (new door lock so M/S is fine) and bizarre operation of the front windows.
It would seem to point to the CCU being on the way out. hey ho.

What results would one expect to see on a scan of the CCCU?
Click to expand...

Just scanned and the only fault stored is Pax front door wont desafe. What does that mean?
 
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