[Warning Light] Electrical circuit fault, battery light

[Lrsn93]

Hello, I have a problem with my berlingo 2012 1.6HDI 

I get an error message after about 5-10 minutes of driving. "Electrical circuit fault" and the battery light comes on.. 
nothing wrong with the car otherwise. alternator charges between 14.4-14.7v so no problem there.. when I try to disconnect the negative terminal of the battery and then reconnect it, I get the error message "Engine fault" and then the car charges 13.5-13.8v?? so disturbing error.. i really need your help! Thanks in advance / Johan

[Sol]

The front terminal of the battery, although it is black, is NOT the negative, it's the positive.

Now the fault you are getting is the LIN network communication failure to the smart alternator. That version of the alternator gets its 12v excitation supply from the battery cable, and the little two pin plug with 1 wire, is the LIN data plug for charge control.

Either the alternator is faulty, or the LIN bus from the engine ECU is intermittently bad.

Usually it's the alternator. The smart version is £400 GBP and they are a nightmare to change over due to bolt positions.

If you get a used one and it's the standard kind, then it will never work on your vehicle. As the plug will not supply 12v to the exciter coils and there will be zero charge.

You WILL find, if you check the battery when the message appears and the battery light goes on, that it is definitely not charging. Switch off the engine and restart, it charges again.

Smart Alternator.

Good tip for you, do not disconnect the battery terminals when the engine is running. Of course you get a fault.

Do you have stop-start?

[Lrsn93]

The front terminal of the battery, although it is black, is NOT the negative, it's the positive.

Now the fault you are getting is the LIN network communication failure to the smart alternator. That version of the alternator gets its 12v excitation supply from the battery cable, and the little two pin plug with 1 wire, is the LIN data plug for charge control.

Either the alternator is faulty, or the LIN bus from the engine ECU is intermittently bad.

Usually it's the alternator. The smart version is £400 GBP and they are a nightmare to change over due to bolt positions.

If you get a used one and it's the standard kind, then it will never work on your vehicle. As the plug will not supply 12v to the exciter coils and there will be zero charge.

You WILL find, if you check the battery when the message appears and the battery light goes on, that it is definitely not charging. Switch off the engine and restart, it charges again.

Smart Alternator.

Good tip for you, do not disconnect the battery terminals when the engine is running. Of course you get a fault.

Do you have stop-start?



Hello! thanks for quick reply ! No, I know that the battery terminal at the front is not the negative terminal and I haven't taken it off when the engine is running

I have a plug in the 12v socket inside the car so I can see the charge all the time, it charges regardless if I get the error message and the battery light is on..

no i don't have the start stop function do you still think it's the Alternator?

[Sol]

I do, if it wasn't the alternator then it has to be the ECU which is faulty or the harness between them.

Google "YouTube Peugeot Citroen LIN fault" you will be surprised. It's very common and is almost always the alternator.

[Lrsn93]

I do, if it wasn't the alternator then it has to be the ECU which is faulty or the harness between them.

Google "YouTube Peugeot Citroen LIN fault" you will be surprised. It's very common and is almost always the alternator.

I'll check this out, thanks! but I still have a hard time believing that it's the alternator that's acting like this, it still charges as it should.. hmm are you sure my year model without start stop has smart alternator?

[Sol]

I've been doing this 10 years and have had 4 of these vehicles since 2011. I have had this fault and I am an electronics engineer, just Google that term and watch the videos.

It sounds like you want it to be something else, like a fuse.

I would not expect it to be that easy. Electronic fault, coming to you from the BSI computer, telling you theres an electrical circuit fault, and the battery light goes on. There isn't many simple options for resolving this. Use a proper multimeter to measure the battery voltage when the red battery light is on, it will be below 14.4v which means it's not charging.

Never mind some gadget inside that tells you the voltage is ok.

14.4v is charging, 13.8v or less, is not charging.

[Lrsn93]

I've been doing this 10 years and have had 4 of these vehicles since 2011. I have had this fault and I am an electronics engineer, just Google that term and watch the videos.

It sounds like you want it to be something else, like a fuse.

I would not expect it to be that easy. Electronic fault, coming to you from the BSI computer, telling you theres an electrical circuit fault, and the battery light goes on. There isn't many simple options for resolving this. Use a proper multimeter to measure the battery voltage when the red battery light is on, it will be below 14.4v which means it's not charging.

Never mind some gadget inside that tells you the voltage is ok.

14.4v is charging, 13.8v or less, is not charging.

no, I believe you, I'm just a bit thoughtful ! I thought it could be something else simple like a bad earth connection to the engine or body .. the car runs like a dream except for my error message .. I use the car every day to and from work and had this error for almost 3 weeks, so I think the battery should be dead by now if it won't charge.. but I will try changing the Alternator! I just have to figure out which one to get, saw there were two different ones one 12v and one 14v

Thanks for all your help! / Johan

[Sol]

Don't get me wrong, I want to help! But there are not too many options for this fault. It's possibly a few issues around the alternator, the ECU, the wiring between them, etc. Not guaranteed to be the alternator itself, but is likely. Some alternators have an electrical magnetic clutch too, to take the load off  the engine when not required. If yours is that kind, then the clutch may be acting up.

Just watch the videos and try some testing, to narrow down the fault. I'm not saying just swap the alternator, and maybe you need an auto electrician to do some testing if you can't do it. But is most likely fault.

When you ask on a forum, either people don't know at all, or they know the possibility of what it could be. This answer is the latter.

I said at the start, it is "usually" the alternator.

There are different output rated alternators, the usual is 150A, but this is at 14v, there are no "12v" ones. The battery nominal voltage at rest is 12v but modern ones charge at over 14v and must maintain 11v minimum when the engine is cranking.

The alternator will usually output 14.4v give or take a few tenths of a volt, at 150A peak current
..

[Lrsn93]

Now the problem is solved!

It was as "simple" as a cable break at the battery controller

The repair cost me a piece of cable and a solder sleeve

[Sol]

Sheesh. Wiring between them.

Ok glad to hear it's working.