A4 Alternator/battery/greabox problems
Discussion
I don't know if all of these are related but any advice would be welcome.
This morning I noticed my battery light came on, but when I revved the engine it went off again. Then came back on. Then off again. Etc Then the ABS and ESP/EPS ? lights came on too. I am hoping that these are related and that it may be loose alternator wire rather than needing a new alternator so will try and have a look later, fingers crossed. Any idea if it could be any other wires that might cause this problem?
Then, heading down to work there was a clunk from under the car and I can now only seem to select (what feels like) 3rd and reverse. Which is a bit worrying. Could this be related to the low battery (currently at 8 volts ish) or do I have potentially a secondary and more serious problem?
Its a 99 A4 Avant 2.8 Quattro with the multitronic auto box.
Update: The gearbox started working again when I was going uphill. Then stopped working again when I braked hard for traffic lights.
This morning I noticed my battery light came on, but when I revved the engine it went off again. Then came back on. Then off again. Etc Then the ABS and ESP/EPS ? lights came on too. I am hoping that these are related and that it may be loose alternator wire rather than needing a new alternator so will try and have a look later, fingers crossed. Any idea if it could be any other wires that might cause this problem?
Then, heading down to work there was a clunk from under the car and I can now only seem to select (what feels like) 3rd and reverse. Which is a bit worrying. Could this be related to the low battery (currently at 8 volts ish) or do I have potentially a secondary and more serious problem?
Its a 99 A4 Avant 2.8 Quattro with the multitronic auto box.
Update: The gearbox started working again when I was going uphill. Then stopped working again when I braked hard for traffic lights.
Edited by Nevin on Tuesday 13th April 13:13
Edited by Nevin on Tuesday 13th April 15:52
The gearbox ECU is switching off because the battery voltage is low. So it goes into emergency running mode.
Same thing with the ABS ECU.
When you brake the brake lights are lowering the voltage.
How are you starting the engine if the battery is at 8 volts, how do you know the battery is 8 volts??
Check the big chunk high current wire from the alternator to the relay plate. They come loose somtimes.
PS its not multi tronic.
Same thing with the ABS ECU.
When you brake the brake lights are lowering the voltage.
How are you starting the engine if the battery is at 8 volts, how do you know the battery is 8 volts??
Check the big chunk high current wire from the alternator to the relay plate. They come loose somtimes.
PS its not multi tronic.
Tame Technician said:
The gearbox ECU is switching off because the battery voltage is low. So it goes into emergency running mode.
Same thing with the ABS ECU.
When you brake the brake lights are lowering the voltage.
How are you starting the engine if the battery is at 8 volts, how do you know the battery is 8 volts??
Check the big chunk high current wire from the alternator to the relay plate. They come loose somtimes.
PS its not multi tronic.
Cheers TT.Same thing with the ABS ECU.
When you brake the brake lights are lowering the voltage.
How are you starting the engine if the battery is at 8 volts, how do you know the battery is 8 volts??
Check the big chunk high current wire from the alternator to the relay plate. They come loose somtimes.
PS its not multi tronic.
Hmm, well its some sort of auto gearbox with a bit where you can bring the stick across to the right to allow you to flick gears up or down. I have to therefore admit to pure ignorance on what it may actually be called if what I was previously told is wrong.
Actually, when I said 8 its more like 10, according to the voltmeter on the dash. It just starts, but wouldn't last night.
It needs a new exhaust downpipe too so I'm taking it into a local independent tomorrow.
Just glad the gearbox seems to be related to the battery issue too and isn't something separate.
Gassing Station | Audi, Seat, Skoda & VW | Top of Page | What's New | My Stuff