Ghost Electrical Issue

[jordann]

Hi All,

I've got a 2003 Audi A3 (8P) which about a week ago upon start up I realised an issue. Firstly the car beeped at me, so I looked at the dash to see the oil light on, with the bonnet open sign alight. I opened up the bonnet, checked the oil level which was fine and closed it again, both lights went off fine and i've just been monitoring it since. I've come out to my car this morning and again the bonnet open sign is alight, so i've got out opened the bonnet up, shut it again and the sign is still alight this time. I drove to work very cautiously, although I triple checked that the bonnet was actually shut.

I know it's damp out so there is a fair bit of condensation build up, I thought it may be a sensor issue but I don't understand what could have bought on the oil light.

Any ideas?

Thank you

 

[pluves1]

Could be as simple as the bonnet microswitch. Some suggest lubricating the bonnet locking mechanism with WD40 after cleaning and checking the microswitch. There is plastic which can break. Not sure if you can just replace the microswitch or if its a new bonnet mechanism.

This might explain the beeping (alarm) and apparently the faulty hood switch can also trigger the low oil level light (not sure how).

 

[jordann]

I've just noticed the condition has worsened, although it still drives. It's almost like I have a phantom ghost in my car ******* with me. On Saturday I turned my car on (after a trip to the Mrs's house) and it made a long beep and the 'low oil' warning light was lit, along with the bonnet open symbol. I turned the car off immediately, checked the oil level which was fine and then shut the bonnet, which turned both symbols off. Yesterday morning I came out and my bonnet open symbol was lit again, I got out checked the bonnet and it was firmly shut, so I drove to work cautiously, everything seemed to be fine. Whilst locking my car I noticed that my indicators don't flash for locking, but they do for unlocking, I assumed it was because the car thinks my bonnet is open so it doesn't fully lock, although I'm no expert. Tonight I went to use my wipers but the pump for the washer jets doesn't work, it doesn't even turn on you can't hear it, but the wipers move. I haven't plugged anything in so I can't imagine it being a fuse, because stuff works I.E the wipers, just not the pump!

Any suggestions?

I haven't got any leaks near the body control module either.

Thanks!!

 

[leshkin]

Have you checked the bonnet micro switch as already suggested? My random logic would dictate that washers get disabled if the controller thinks that your bonnet is open.

Also check that all of your doors lock, together with boot - lights not flashing when locking may indicate that there is a problem communicating with one of modules.

Best bet is to scan the car with VCDS, as door controller module communication issues might not light up dash lights.

 

[jordann]

I haven't checked the switch just yet, i'm going todo that later, along with disconnecting the battery. My uncle has said that he's had a few cars in recently with a spike and after disconnecting the battery for 5 minutes the issue cleared. Now you've said that the washer jets won't work whilst the boot is open it makes sense.

I'm paranoid about not locking things because i've got a brain that is only capable or remember stuff for about 2 minutes so I triple check both doors and the boot when I walk away, they all appear to lock fine. Unlocking the car sets the indicators off as well. I just thought because the car thinks the bonnet is open is doesn't flash letting you know something is ajar.

Thanks.

 

[leshkin]

Scanning the car with VCDS might show some module errors, which may help in troubleshooting this.

I mentioned that the washer jets might not work if the ECU thinks that the bonnet is open, but I am not certain of this - just guessing.

The indicators should always flash when you lock the car by default, not unlock it, and if they don't flash when the locks are engaged then there is likely something that is not locking or not communicating with the ECU correctly.

I suspect that disconnecting the battery will reset the ECU and may help if the ECU is the problem, but your problem is likely to come back if the issue is with with another module or switch. In that case VCDS or similar is your only friend.

 

[NHN]

Bonnet lock is faulty or gunged up, get it cleaned 1st & test & then swap out if still not right & yes locking flashes wont show if bonnet isn't detected as closed fully.

 

[jordann]

Just incase anyone else is having this mysterious issue i've found a fix, i'm not sure how long for mind. It's as simple as taking off the battery for 5 minutes and putting it back on, it's cleared all symptoms.

- Bonnet open symbol has gone.
- Oil low light has gone.
- Washer jets work again.
- Indicators flash on lock.