load signal alternator cable

[kieranlt]

I've been having the traction control light come on for a few weeks now 10-15mins after driving. After reading up about this I found the broken wires and extended them, the battery light now comes on after turning the ignition but the traction control light still came on after driving.

Took it to my local garage and they checked and cleared all codes for me, but again 10-15mins after driving away the light came on again.

Anyone got any ideas? Spent money thinking it will fix the problem but it all seems a waste now as I could have spent it else where on the car.

They found the following codes:

18265 - LOAD SIGNAL ERROR MESSAGE FROM ECU

- P1857 INTERMITTENT

[Georgevrs]

Annoying as it may be I would recommend going back over your original job, did you solder it or use an inline plastic style thing that you crimp? Also see if there is any more breaks that the repair didn't fix. Lewis

[kieranlt]

I used bullet style connections. The fact that the battery light now comes on makes me think the job is ok? Saying this the end where the cables had broke originally the copper was black rather than the nice clean copper colour.

[Georgevrs]

When I did mine I cut as much as I could out of the loom and replaced with similar wire I bought from Audi but I soldered as I think it will withstand weather better hope this helps. Lewis

[FinnVrs]

http://wiki.ross-tech.com/wiki/index.php/18256/P1848/006216

http://www.justanswer.com/audi/1kdl4-p1857-audi-a6-4-2-c5.html
 

Edited 7 September, 2013 by FinnVrs

[mpow3r]

sorry bring up an old thread but mine is doing this with the traction like coming on after about 10 mins of driving and I also get the load signal on VCDS, BUT my battery light comes on fine with turning ignition??  I will be having a look under the alternator at the load signal wire but could there be another problem?  I read that the ABS unit is linked to TC as well so could this be faulty?  II cant remember the mech saying anything about ABS fault on VCDS?

[Breezy_Pete]

There are two wires from the alternator whose functions and fault behaviours seem to get mixed up. They're often both broken, which helps confuse the situation.

 

DFM, the one broken in your car, goes to the engine ECU, telling it how much of the alternator's available capacity is being used moment by moment. When broken, a fault code "load signal" appears which can be read in VCDS, and puts the ASR light on after 10 mins of driving for some reason, in cars with ASR. The battery light still comes on with ignition.

 

The other (blue) one goes through into the cabin, to the Onboard Supply Control Unit near the relay panel, and that communicates with the dash cluster to illuminate the battery light at ignition on, or when the alternator output voltage drops below a certain point (gonna check what that point is this afternoon all being well).  Its function is to help the alternator start up correctly, and then to monitor the voltage being generated. This is the one that causes the battery light not to work when it breaks. 

[mpow3r]

That certainly clears things up.  Many thanks for the explanation.

[mpow3r]

Just a quick update.  I did the mr Muscle thing today and while I was waiting for the foam to do its thing I followed that guide someone putup from a Seat Ibiz. I looked around for those wires as in guide under alternator but couldnt see any broken wires (Alternator is under drivers side.) I then moved to passenger side and found a plug with one wire broken. trie dto skin it so I could wrap new wire and join it but twice I cut straight through (wire looked rusty under insulation, im also a bit crap at cutting, lol eve though I have the tool for cutting insulation off), I managed to do it in the end with like 5mm of wire remaining. Cover it all in insulation tape and packed up.

 

First thing I noticed when I got in the car was that teh courtesy lights were working when I opened and shut the door (they havent worked since I bought the car).  Went for a drive, booted it about to get rid of MM, enjoyed the hybrid power but then after about 10-15mins the TC light came on again.  So i'm going to have to look harder for breaks in the wiring.

[Chris Berry]

There are two wires from the alternator whose functions and fault behaviours seem to get mixed up. They're often both broken, which helps confuse the situation.

 

The other (blue) one goes through into the cabin, to the Onboard Supply Control Unit near the relay panel, and that communicates with the dash cluster to illuminate the battery light at ignition on, or when the alternator output voltage drops below a certain point (gonna check what that point is this afternoon all being well).  Its function is to help the alternator start up correctly, and then to monitor the voltage being generated. This is the one that causes the battery light not to work when it breaks. 

 

Hi Wino,

 

I have this problem as I dont have a battery light appear on my dash - been like that for years. So far it doesn't seem to have any adverse side effects apart from sometimes my power steering might not kicking in straight away when its very cold, but I had put this down to something else rather than the load signal alternator cable issue (which I only found out about this year).

My question is this - where is the normal & most common place to look for the broken blue wire? I've taken a look around & can see which cable you might be referring too. I'm probably looking in the wrong place. I've seen a close up picture of a plug with a broken wire but I couldn't see where that was from. Can you point me in the right location?

 

Thanks.

[mogwye]

Try here http://www.seatcupra.net/forums/showthread.php?t=209472.

 

Oooops, you have already been there.

 

DB.

Edited 21 August, 2015 by mogwye

[mpow3r]

Hi Wino,

 

I have this problem as I dont have a battery light appear on my dash - been like that for years. So far it doesn't seem to have any adverse side effects apart from sometimes my power steering might not kicking in straight away when its very cold, but I had put this down to something else rather than the load signal alternator cable issue (which I only found out about this year).

My question is this - where is the normal & most common place to look for the broken blue wire? I've taken a look around & can see which cable you might be referring too. I'm probably looking in the wrong place. I've seen a close up picture of a plug with a broken wire but I couldn't see where that was from. Can you point me in the right location?

 

Thanks.

Have you got under the car?  If not get it on a ramp or axle stands and have a hunt around underneath. Its the only way of finding them.

[Breezy_Pete]

Hi Wino,

 

I have this problem as I dont have a battery light appear on my dash - been like that for years. So far it doesn't seem to have any adverse side effects apart from sometimes my power steering might not kicking in straight away when its very cold, but I had put this down to something else rather than the load signal alternator cable issue (which I only found out about this year).

My question is this - where is the normal & most common place to look for the broken blue wire? I've taken a look around & can see which cable you might be referring too. I'm probably looking in the wrong place. I've seen a close up picture of a plug with a broken wire but I couldn't see where that was from. Can you point me in the right location?

 

Thanks.

It's always a problem when taking photos of car bits; too close in and you lose the context of where on the car you're supposed to be looking. Working out the orientation of the photo can be hard too, especially if it's taken from a 'lying on the ground on your back' position.

 

I'll try to get a sequence of photos or a video to show the position as clearly as possible, over the weekend. Can't do a vRS, but I can show you on 1.2 and 1.4 engines, hopefully it's pretty similar. Front of gearbox, on a bracket, low down, is the best hint I can manage in words.

 

The blue wire may also be busted or have a bad connection at/near the point where it goes through into the cabin, roughly underneath the driver's side wiper-arm pivot. Or maybe even at/near the plug where it connects to the back of the alternator.

 

You should be able to measure approx. 11-12V at the (unplugged) alternator plug pin that the blue wire goes to, with ignition switched on. If it's not there, there's a break in the wire somewhere.

[Breezy_Pete]

Here you go Chris,  a couple of photo sequences, one of my Polo (type 9N, 53-plate, 1.4 BBY engine), the other a Fabia (Mk1 05-plate, 1.2 AZQ engine).  The Polo is a piece of cake to find the relevant connector, the Fabia you do need to take the engine undercover off, but that's just 3 screws each side, can easily be done with car on the ground, as it is in these pics.  Diesel Fabias with the full undercover are going to be harder, but I think there might still be a hole that you can look through (gearbox air-cooling?).

 

Fabia (1.2 12v):

 

 

 

 

 

 

 

 

Ignore the pink-starred connector in the above image, that's the pre-cat lambda connector (not relevant to here). The red arrow points at the relevant connectors as seen from below.

 

This one is the clearest shot of the relevant connector and wires, not sure where that was taken from.

 

 

 

I think, from what I've seen/heard on here, most Fabias are more like the Polo, with the alternator signal connection the lowest pair on the bracket.

Edited 17 October, 2021 by Wino

[Chris Berry]

Top man! Thanks for that.

 

Might take a look if it stops bloody raining!!

[Breezy_Pete]

No probs.  Take some photos if you find it.

[TMB]

Looks like a nice new dogbone on the Polo? :p

[rum4mo]

Looks like a nice new dogbone on the Polo? :p

 

I was more impressed with the new front exhaust section!

[TMB]

I was more impressed with the new front exhaust section!

 

Haha

[Breezy_Pete]

I'm finding that super-rusty connector bracket on the Polo a little upsetting...

I bet that's one of those parts that's tricky to find a part number for.

[mpow3r]

can the plug including wiring be bought from main dealer?  Wire from mine has been cut very short and im not even sure if it was re-connected properly.  Anyone have the part number? Or can I just go there and ask them for the alternator load cable?

Thanks

[Breezy_Pete]

Its a connector pair, a plug mated with a socket, which side of the metal bracket is yours busted left or right?

 

One side (left in my pictures) goes off to the alternator, the other (right) side to the engine ECU (purple/green wire) and firewall connector into cabin (blue wire), respectively.

 

By far the simplest repair is to ignore/cut out the connector pair, and just join the wires around them, splicing in fresh lengths of wire. Might make it awkward in future if you ever needed to disconnect, but I think that's a fairly remote possibility.

 

Edit: Something like this:

 

[mpow3r]

Thanks so much mate.  Explained perfectly for a dumbo like me. 

[mpow3r]

sorry dumb question time...

 

do i have to use same thickness of wire? Would something like speaker wire do?

 

Thanks in advance

[Breezy_Pete]

Make sure the copper is just as thick as in the existing wires; thicker rather than thinner if anything. Main thing is to try to weatherproof the joints if you want it to last. Self-amalgamating tape is good stuff, or adhesive-lined heatshrink if you're soldering the joints.