Leon OBD fault occurring at 16.8 v

**beeroclock** · 15-11-2022,09:59 AM

OK thanks, is there any way that the alternator can be tested?
cheers

**Crasher** · 15-11-2022,12:54 PM

Well I think you are doing. Remind me, did you replace the battery monitoring unit 1K0 915 181 H?

**beeroclock** · 15-11-2022,01:12 PM

Hi, no I unplugged it as you said but it made no difference. Do you think it might be worth trying a replacement?
Cheers
Nigel

**Crasher** · 15-11-2022,04:20 PM

Possibly, they are silly money but the supplies have been erratic. The way it works is the BMU controls the alternator bu LIN BUS and according to a Self Study Program I read, if the BCM or the wiring to the alternator fails, the alternator is supposed to default to, I think, 13.5v.

**beeroclock** · 15-11-2022,04:35 PM

OK so if that BMU had failed it would have defaulted to 13.5v. That correct?
cheers
Nigel

**Crasher** · 16-11-2022,10:04 AM

That is what I read a few months ago but I can't find the SSP, it was for a T6 where the LIN wire had broken (a common fault) and the SSP said if it lost LIN comms the alternator would default to, I think, 13.5v. I have a Self Study Program for the CAYC engine which goes into a little detail about the LIN alternator but does not mention the default voltage but it wouldn't be 18v! I have triple checked the alternator you have fitted and according to ETKA and then Tec-Doc using the genuine number it is correct.

**beeroclock** · 16-11-2022,10:10 AM

Ok thanks, so what would you do next? I am stuck stuck!!!
cheers
Nigel

**Crasher** · 16-11-2022,10:37 AM

I would be taking a deep breath, ordering another alternator and praying I was right but really I can't think of anything else; the voltage stabiliser still bugs me.

**beeroclock** · 16-11-2022,10:45 AM

OK, whats bugging you about the stabilizer? Because its bugging me too, the clue is in the name for me, it should stabilize the voltage and thats exactly what I need.
Cheers
Nigel

**Crasher** · 16-11-2022,11:20 AM

I only have the SSP for the Golf where the stabiliser is mounted differently but looking at the wiring diagram unplugging it should not kill the car and what is does could generate too much voltage. I was going to log into erWin Seat for an hour and find the SSP and study the diagrams on there but the erWin system is down... ohh, no its back up. I will be back in an hour or so... no, it's still broken.