Odd, odd behaviour

[Northernstar002]

Hi all,

My 2006 A6, 2.0 TDI SE has been acting very odd lately.

A week after I got the car I had an issue where it refused to start. It was warm and parked on a slight angle, half on and half off the curb outside my house. After I left it for 20 mins it started perfectly as though nothing had happened.
I took it to a local VAG dealer who took the codes off, iot pointed to the Engine control module. But since the starting issue had cleared itself, we agreed to clear the codes to see what came up if it should happen again - which it hasnt, until yesterday (three days after the first event).

So, I'd been driving from Plymouth to Portsmouth for at least 100 miles without any issues at all. I stopped off for a 'comfort break' for 5 mins or so. When I came to start it again it took three attempts before it fired up. Then the dashboard lit up like a Christmas tree as it thought that my brakes had a serious fault. The Traction control light, ABS light and handbrake light all came up and I lost cruise control. Probably a wheel speed sensor (I've seen this on other cars).

It drove and broke fine after it started and the lights continued to be illuminated along with a big red flashing brake icon (with an '!' in the middle), I also had an amber P with a line through it at the top of the central display. Another oddity (perhaps unrelated) was that the rear wash wipe parked itself in the central position and stayed there. Regardless of what I did with the switch. I can see from the SH that there was a recall from Audi to fix an issue where the fluid pipe had come apart and dowsed everything including the wiper motor.

Anyway, I parked up after another hour's driving and left it for perhaps another 2 hours. When I came out to start it again, not only did it start perfectly first time but the faults with the brakes and dash lights had dissappeared and the rear wash wipe activated and parked itself!

Do I have an odd fault in the ECU or a self repairing car?

I'm having it in this weekend to get codes read again but if anyone has any ideas, I'd love to hear.

Cheers,

[kite]

I would check the battery, Audi's can be quite sensitive to a dying battery.

[MarkTM]

From personal experience the first components to be affected by a bad battery...or indeed an alternator, is that the car switches off TC/ASR/EPB and transmission to prevent damage from overvoltage. So if you have any overvoltage codes it may be a faulty alternator regulator. A voltage check at the battery end both switched off and then under load (air-con, lights, heated seats and stereo on) should see a 14.4v supply to the battery.....any higher and the car will shut down.

Await to see your codes!

[Northernstar002]

That would explain why my on board battery meter is reading 100% all the time. If it's overcharging then it would be 110%.

I wasnt able to get the codes in the end but i hope to this weekend.

[Northernstar002]

Hi All,
So I have a prognosis. My local VAG specialist who ran the fault codes about 5 weeks ago (and then cleared them) ran them again and found that Engine Control Module is at fault - showing code 01314 - 004 - No Signal/Communication Intermittent. They suspect that the ECU (in the scuttle panel) may have taken a swim at some point and that the connectors may be corroding. I assume that there are drain holes in this area? I have a Rover 75 which suffers from exactly the same design flaw but these are easy to rod out. just a few clips from some plastic trim and you're in, but my specialists are quoting about 2 hours work to get to the ECU.

The module itself is only a £20 item (or thereabouts) plus another £110 in labor to get to it but the costs could skyrocket depending on how far the water has travelled up the loom.

The car is covered on a 3 month warranty for Engine and Gearbox, which I suspect, wont cover the the ECU. That said, I still have my statutary rights to have a car thats fit for purpose and doesnt leave me stranded (which it has, 4 times in 5 weeks). I dont expect it to be in showroom condition but for £5K I expect a car that starts reliably at least.

Another code that goes with 01314 Engine Control Module is 008 - Implausable Signal - Intermittent.

I also have another code that reads: 18055 - Check Coding Of ECU on Powertrain Data Bus - P1647 - 004 - Intermittent. Would it be best if i can get the data sheets scanned or would someone like to have them faxed (if folk still do that)?

The data also showed 01699 - Motor for Central Locking hatch is 009 - Open or Short to Ground. Could this be why my rear wiper parks itself at odd angles? Is it designed to cut out when it thinks the boot it open? I have, in my service history, a recall notice from Audi to investigate the washer pipe to the boot lid. Do I have any recourse on them as their work hasnt lasted very long. It was done in 2011 and the rear washer isnt giving any fluid. If it's douse the motor then it's their fault isnt it?

Grateful for your thoughts,

[Northernstar002]

What do we think? Easy fix?

[niall campbell]

The ECU module sits on right hand side of scuttle area and is quite high up, however never say never and would take a lot of water to get in there. Connections are also protected with tamper proof screws.

There are 2 or 3 drain holes in the scuttle and mine was blocked the other week , 2006 model with 63,000 miles.

Any water in footwell ?

[Northernstar002]

nope, no water that I've detected. Wouldnt I hear that amount of water sloshing around?
Is it easy to get to the drain holes and rod them out?

[niall campbell]

You wont hear the water & its easy to do

Hardest bit is taking off the wiper arms

[MarkTM]

Invest in a wiper puller, less than £5 delivered off ebay.