I found some information on a Bosch website about something that looks very similar to the BCSU fitted to the negative terminal which is also a Bosch part:-

"The electronic battery sensor (EBS) measures the current, voltage and temperature of 12V lead-acid batteries with great precision. The battery state detection algorithm (BSD) integrated into the EBS calculates the current and predicted state of charge and function of the battery from these base parameters and indicates battery aging effects. This information is passed on to a higher-level control unit, e.g. the electrical energy management (EEM) system. If needed, that system implements suitable measures to ensure the power supply to ancillaries that are important or critical to safety."

Electronic battery sensor

The electronic battery sensor (EBS) provides reliable and precise information on the status of 12-V lead-acid batteries.

www.bosch-mobility-solutions.com

I wonder if a fault with this unit causing it to think the battery is flat or perhaps not communicating with the cars control system (EEM) means that the "Battery manager fuse box" is being stopped from switching on power to none essential circuits such as the mirrors, electric windows and starter.

When I get a chance I will disconnect what I assume is the BCSU bus connector and see what happens.

 

I tried to start the car this morning and the original problem had returned. I disconnected the connector on the side of the BCSU - turned the ignition on and got Engine fault message but the car started and ran fine with no warnings other than the Service dash light - onboard diagnostics showed Engine fault.

Reconnected the wire on the side of the BCSU and all the errors had gone and the car started and ran fine. I can only assume there is an intermittent fault on the BCSU or it is locking up somehow and removing the power is resetting it. If it happens again I will just disconnect the battery and see if this has the same effect - I think I have read of other people with a similar fault doing this with success.

 

I had the fault again this afternoon and didn't have time to disconnect the battery with the 3 minute rule so just left the BCSU disconnected so I could use the car, I have ordered a new unit from a Peugeot dealer - £100.39 inc VAT, should arrive tomorrow so fingers crossed it solves the problem.

I can't find out much about the BPGA other than it is a sort of smart fuse box that can disconnect circuits when instructed by the cars control system.

 

I have just fitted the new part - Peugeot call it a 9814653780 BATTERY UNIT. On starting the car the service light was on and the low beam warning light on the dash was flashing. The onboard diagnostics showed a check fog lights error. Switched the fog lights on and off and the service light went out and the flashing headlamp warning went away.

Car is starting and running well with no errors showing but it will be some time before I am confident the problem is solved as the old unit would run for long periods without problem. I will update this thread if I get any more problems.

For info, I read on another forum that when this unit is first fitted or after the power has been removed from it it goes into a calibration mode in order to learn about the battery and is less likely to flag a faulty battery. This might explain why some people having problems with this unit or the battery have found that disconnecting the battery can cause the fault to go away - at least in the short term.

 

There should be a mention of the "Load Reduction Mode" in the car's handbook. The battery state monitor on the negative terminal of the battery is meant to monitor the battery condition. It is linked to the BSI and measures things such as battery temperature. If it detects that the battery is under too much load the BSI shuts down non essential things such as air-conditioning and the heated rear window. I understand that sometimes these unit can crack which can lead to a poor battery connection. If the unit is in good condition it should not stop the car from starting.

The BPGA is often called a battery protection unit. If is a safety device that turn off the power in an emergency. It is has solid state microprocessor controlled relay that is connected to the BSI. These units are known to fail on the 308 and in the case of the 308 Mark II the car will not crank and there will be no power at the OBD connector so some scanners will not work. I have linked to a video which relates to the BPGA in a 308 Mark I. In this case the solid state relay was replaceable but I understand on the Mark II its integrated into the BPGA.

 

Thanks for that information Ian. This is how I think the system works:-

The BCSU fitted to the battery negative is purely a battery monitor and supplies the following information to the BSI -
Battery voltage, battery current drain/charge, battery temperature and battery charge state.

The BPGA is just a switch controlled by the BSI it feeds no information back to the BSI. Its function is to disconnect none essential things like the AC, the heated rear window and electric windows if instructed by the BSI.

The BSI is the brains of the system, it uses information from the BCSU to control the BPGA.

This is what I think is happening in my case when the fault occurs - The BSI has received information from the BCSU that has made it think starting the car would be dangerous and the BSI is not allowing the starter motor to operate or the BPGA to power none essential circuits. If I remove the bus connection from the BCSU the BSI just thinks the BCSU is faulty and allows the car to start because it has no reason to think it would be dangerous.

 

Back to square one! I just went to try the car and the fault is still there. The only difference this time was when I removed the bus connector from the BCSU the car still wouldn't start - plugged it back in and it started with just the normal check fog light error which cleared when the fog lights were switched on.

 

Did you look at the video I gave you the link to? Your understanding of the BPGA is not quite right. It contains a large number of fuses. Several fuses are directly connected to the battery the others go through a microprocessor controlled switch (sometimes called a solid state relay).

I have attached a diagram for 308 Mark I BPGA. The BPGA in the Mark II is different but the principle is the same except on the Mark I:
(i) Only F3 (power to battery monitor) is directly connected to the battery
(ii) Much of the power by-passes the BPGA and goes straight to the BSM (main engine fuse box).
As can be seen in the video when this switch fails the car will not even crank.

Here is a link to another forum discussion with a faulty BPGA on a 308 Mark II diesel. The discussion switched to Private Messaging and I know an auto electrician visited and by-passed the BPGAs switch and got the car started. In the last PM the guy was trying to buy a new BPGA:

308 no ignition no start wing mirrors closed

hi everyone first post hope someone can help have a 2015 mk2 308 1.6 hdi which is not starting, wing mirrors dont fold out and simply goes in to economy mode active have read somewhere could be the bpga (supplies protection and management unit) or needs a new battery i changed the battery...

www.peugeotforums.com

Does this look like your BPGA:

Here is a diagram of a Peugeot 508 BPGA which has more directly connected fuses.

In the case of the battery monitor function its output is monitored by the BSI. The BSI is linked to the BSM (main engine fuse box) and the BSI disables the a/c and heated window via the BSM.

 

My own 307 will start fine but once you On AC and continue driving for about 30 mins, it will start to show BATTERY CHARGE FAULT and it will drain the battery completely. So also if you drive without AC for like 5 kilometers the same error message will surface. Please help me

 

I suspect you have an alternator fault but I think you would be better to start a new discussion. This discussion is in the 308 section and your question may not be seen by the right people.

 

Ian thank you so much for taking the time to post such a useful and comprehensive reply.

I did watch the video and it was really useful and had got me thinking I too might have a BPGA problem. I did know about the fixed fuses in the BPGA I was just keeping it simple to help me understand the interaction between the BSI and the other modules as I think that is my problem.

Thank you for the circuit diagrams and the picture of the BPGA it is very similar to the one on my car. I will go and do some more investigating when the rain here eases.

 

Next time when the car fails to start the best thing is to get a multimeter and measure the voltage at the output of all the fuses. You should be able to see which fuses are connected to the battery so you will know if the relay is failing.

The two cases I know of (including the one I linked to) the people found that in most cases the car would usually start after a few tries but eventually reached the point where the BPGA failed completely. In the case of the 308 Mark I you can just replace the solid state relay module as in the video but with the 308 Mark II you have to replace the whole unit.

 

Thanks again Ian. I have been monitoring the voltage on the stud of the BPGA that is at the bottom left of the unit in the picture you posted above, the voltage here seems to be controlled by the relay. If the car is left for some time the voltage here is 0V as soon as a door is opened or the key fob used the voltage switches to battery voltage. I can hear a click from the BPGA that sounds like a mechanical relay. The stud stays at battery voltage for about 30 mins (it is too wet to hang around and time it exactly). The fault hasn't shown today but I am 90% sure when I measured it yesterday when the fault was present it was 0V.

The fault seems to have all the characteristics of a failing mechanical relay contact - intermittent and getting more frequent with time. I have come to the conclusion I need to replace the BPGA. The options I have found are:-

Peugeot dealer - the list price seems to be £300 inc vat.
Ebay second hand unit £110 inc delivery
Aliexpress £105 inc delivery but 3 week shipping time.

I am going to make a link to bypass the relay (similar to the one in the video) to enable me to keep using the car in the meantime.

 

The options I have found are:-

Peugeot dealer - the list price seems to be £300 inc vat.
Ebay second hand unit £110 inc delivery
Aliexpress £105 inc delivery but 3 week shipping time.

I am going to make a link to bypass the relay (similar to the one in the video) to enable me to keep using the car in the meantime.

Yes the guy with the diesel 308 Mark II (Steve112) had the same dilemma. The Aliexpress sellers I have dealt with have been very good but you never know the source of the items they are selling. Some items are secondhand. I have found the feedback reliable.

It was interesting that you could hear the BPGA clicking. I have seen it described as a solid state relay and had a suspicion was that this wasn't correct. There are some really good power field effect transistors (MOSFETs) but I hadn't seen any that could handle the current. A MOSFET is less likely to have the sort of intermittent fault people are getting. They may be called solid state because they are a complete package with a microprocessor.

I think the 308 was one of the first Peugeot to have a BPGA. Apparently, it has multifunctions which are worth having but a temporary bypass is probably okay. This is what I found on the C4 Owners forum Forums / Problems and issues / BPGA Unit - C4 - DS4 Owners. I am not sure all of this is implemented on Peugeots because Peugeots have seperate battery monitors on the negative battery lead:

"[...]The Battery Management & Disconnect Unit is a stand-alone ECU that is installed in in-line position on the positive battery cable. The proprietary electronics contained in the Unit perform battery State-of-Charge, State-of-Health and diagnostic monitoring to optimise battery life and performance. At the heart of the Unit is a current sensor and a programmable micro controller that contains the State-of-Charge and State-of-Health algorithms to control the state of charge/ discharge of the installed battery. This ensures that the battery is maintained in a high state of charge and is protected from quiescent drain and discharge in use - a major contributor to improved reliability and electrical system integrity.

In the event of a serious accident that results in the deployment of the vehicle airbag system, the potential hazard caused by a damaged electrical system is minimised. A signal from the on-board crash sensor to the Unit automatically disconnects the battery, in less than five milliseconds, so preventing an electrical source from short circuits in the electrical system.

The disconnection capability of the Unit provides for automatic protection of the car network in case of faulty operation such as reverse battery jump start.

Apart from this integrated function, another feature of great interest for consumers and car makers is the easily accessible manual battery disconnection capability. It protects the battery from quiescent current drain during long term when the vehicle remains stationary.
During logistic loop, whether it is off-shore shipment or long period parking, the disconnection preserves the battery from discharge. The result is an optimally charged battery for a clean start and by avoiding “deep discharge” it contributes to the extended battery life.[...]"

 

Monitored the BPGA over the weekend and the fault never appeared. The amount of time the relay in the BPGA stays on after the car is left seems to be related to battery condition the time reduced until it was down to a couple of minutes. The relay is activated by opening the bonnet, the drivers door (but not the passenger) or using the key fob.

I went to start the car this morning and the fault was back so fitted a link I had made as shown by the white wire in the picture. It is fitted to two m6 studs on the BPGA that are normally hidden by sliding plastic covers. Car then started.

I have ordered the ebay PCBA which comes from a breakers - will update when it arrives.

 

Monitored the BPGA over the weekend and the fault never appeared. The amount of time the relay in the BPGA stays on after the car is left seems to be related to battery condition the time reduced until it was down to a couple of minutes. The relay is activated by opening the bonnet, the drivers door (but not the passenger) or using the key fob.

I went to start the car this morning and the fault was back so fitted a link I had made as shown by the white wire in the picture. It is fitted to two m6 studs on the BPGA that are normally hidden by sliding plastic covers. Car then started.

The first thing I would suggest is that you check if the white wire is getting warm after you have used the car for a while. It's hard to determine the current rating you need for the wire. If you simply add the current rating of all the fuses you would need a very large wire.

I have attached a sample wiring diagram (starting circuit) for a 308 Mark I. I don't have access to the Mark II diagrams. They are available at the PSA Servicebox website but you have to pay to access them. I think the Mark I diagrams are near enough because they show the link between the BPGA (1032) and the BSI (BSI1). There is also a power connection to the BSM part of the engine fuse box (PSF1). This power connection is controlled by the engine ECU (1320). The BSI normally turns off about 3 minutes after you turn the car off and shut the drivers door. I would expect the BSI to turn the BPGA off at the same time. I just checked on my car its a 307 but I suspect the same arrangement still applies:
(1) If the car is unlocked the odometer display turns ON if you open the drivers door but not if you open the passenger door.
(2) Using the remote to unlock the car turns the odometer display ON.

If the odometer is displaying you know the BSI is awake but I don't know if the BPGA turns on at the same time. The BSI appears to have different wake up stages. For example I have an iPod connected to the radio and it turns on if I open the passenger door or boot but the odometer display doesn't turn ON.

N.B. You can usually tell when the BSI turned off because the odometer display is off but don't rely on this if you need to disconnect the battery because it still may be partially active. Disconnecting the battery while the BSI is awake can corrupt it.

 

Ian - thanks for the wiring diagram and information, it all helps to build a picture of how the different components interact.

The wire I used for the link is 15amp mains flex. I have connected the three core wires together so should be good for a lot more than 15amps. I have been disconnecting the link if the car has been left for over 30 minutes as a precaution against draining the battery - I have not noticed it getting warm at all.

My observations have been that the relay in the BPGA can stay energised for as long 30 minutes and stays on far longer than the odometer display. It does depend on the state of the battery and by the end of the weekend when the battery was low it was only staying on for a couple of minutes.

When the BPGA is activated, say by opening the door, it will energise the relay. The relay will then stay energised until the BPGA goes into standby so an intermittent fault will persist until the relay switches off and on again. I think this is why some people have found the problem will disappear if the car is left for a while or the battery disconnected. I suspect disconnecting the BCS bus connection will also do this which would explain why I initially thought the BCS was the problem.

 

Thank for the feedback. It sounds like the description of the BPGA on the other forum is correct. I wish I could find the original source of that information.

A lot of Peugeots (including the 308 Mark II ref Owner Handbook) have an economy mode setting that turns the non-essential equipment off if the battery voltage drops too low or after 30 minutes if the engine is not running. It sounds like the BPGA supplements this function. For obvious reasons the sidelights are not controlled by economy mode. There was recent case on the forum where the sidelights were left on for 36 hours, which ran the battery flat, and as the BSI was active it got corrupted.

 

I found the diagram I posted was cut off so I have updated it.

 

Ebay/breakers yard BPGA arrived today and I have just fitted it. Fingers crossed it seems to have cured the problem and everything is working but it will take some time before I am completely confident.

A few observations:-
1) The part number for my car is 9675350280 the part I ordered was 9675350380 which came from a 3008 - they were listed as equivalent on Aliexpress. The new part was missing two fuses that were fitted to my original but it was easy to swap them over.
2) As Ian posted was the experience of others my unit was failing more and more often.
3) While checking the new unit fuses I noticed that the ones that are connected through the "relay" in the unit were connected to the battery feed. I thought this meant that the unit was faulty but after connecting the battery I heard a click and the battery connection to these fuses was removed.
4) After fitting the new unit the electric windows would only go up in stages. The handbook notes that when the battery is disconnected the windows safety anti-pinch function is lost and needs to be reset - this cured the problem. I must have disconnected the battery a dozen times before and never had to rest the anti-pinch function before.
5) The "relay" in the unit is hidden behind a plastic cover and it looks like I will need to drill out some spot welds in the metalwork to get to it. I will do this when I have more confidence that I will never have to refit it.

Ian - thank you so much for all your contributions they have been a great help to me and hopefully anyone else with this problem who finds this thread.

 

1) The part number for my car is 9675350280 the part I ordered was 9675350380 which came from a 3008 - they were listed as equivalent on Aliexpress. The new part was missing two fuses that were fitted to my original but it was easy to swap them over.

I have found several listings where they claim the 9675350280 and 9675350380 are equivalent. If you look through the servicebox you often find Peugeot have a new recommended replacement part. My guess the __380 is a later replacement for the __208. You usually find that these part numbers are the component manufacture's part number rather than the official Peugeot part number.

3) While checking the new unit fuses I noticed that the ones that are connected through the "relay" in the unit were connected to the battery feed. I thought this meant that the unit was faulty but after connecting the battery I heard a click and the battery connection to these fuses was removed.

That's a bit odd it suggest the relay contacts are normally closed which is not what the diagram suggest. It would be worth checking what the original unit does.

4) After fitting the new unit the electric windows would only go up in stages. The handbook notes that when the battery is disconnected the windows safety anti-pinch function is lost and needs to be reset - this cured the problem. I must have disconnected the battery a dozen times before and never had to rest the anti-pinch function before.

I think that is probably depends on how long the battery is disconnected. The Windows ECU probably has a capacitor that help hold the memory for a period of time. For example when you remove the battery from a key fob it can lose sync with the car but in practice I have found the tantalum capacitor across the battery has a enough charge to keep the memory.

5) The "relay" in the unit is hidden behind a plastic cover and it looks like I will need to drill out some spot welds in the metalwork to get to it. I will do this when I have more confidence that I will never have to refit it.

Yes that will be interesting but I agree make sure the unit is faulty before doing that. I am fairly sure the BPGA is the cause of your problem but there can be other causes for your fault e.g. BSM, BSI or engine ECU. If this doesn't solve the problem it would be worth registering with servicebox and searching for the wiring diagrams. You need to pay to get the actual data (e.g. 8 Euro/hr) but you can usually see a list of what is available before you pay.

 

Used the car a few times today with no problems, early days but encouraging.

The battery was probably disconnected for about a hour while I fitted the new unit so probably explains the electric windows losing the anti pinch data

The old unit is showing the "relay" connected fuses open circuit from the battery feed, I can only think if it is a mechanical relay it is a latching type. I might find out more when I dissect the old unit.

 

An update to hopefully close this thread. When searching the internet for the cause of my problem I found several threads where people had had the same problem but not posted what the solution was - so annoying.

It's now 17 days since the new BPGA was fitted and I have not had any problems so I am confident that was what was causing the problem.

I have taken the old unit apart and there is a mechanical relay and some electronics but it is all encapsulated in potting compound so no chance of repairing it.

 

Thanks for the update. It was interesting to hear that it was mechanical relay. I wonder why the guy in the video thought it was a solid state relay.

 

Good day Dave,

I am having trouble with my Peugeot 3008. Battery charge fault has come up a few times to the point where eventually the car does not start. I need to flash lights and do various bits of trickery to get it started. It's intermittent. When it initially happened i checked voltage at battery, only showing 12 when car running. After disconnecting battery overnight and managing to start again the voltage was 15. Works for a while, then same fault and problems starting. Usually wont start first thing morning unless battery has been disconnected overnight.

Have you had any further issue since changing out the Pbga?

Kind Regards
Steven

 

Hi Steven,
I am gad to say I have had no more problems since changing the BPGA but I am not sure you have the same fault as I had. If you were only seeing 12V at the battery with the car running the alternator is not charging for some reason.

When you got the battery charge fault was the engine running? When the car won't start does the starter motor turn the engine over?

 

Thanks for the response gents. I should note that I have very little knowledge on what's under the bonnet of the car. I apologise if what I say doesn't make much sense. Please highlight anything that is confusing.

So the problem started with battery charge fault appearing when trying to start the car. It would appear and stop the car from starting. Wouldnt even thurn the engine. I would lock and unlock the car and then it would work. No battery charge fault. It then got worse over the next few days, it would happen more frequent. One morning it complete gave up, wing mirrors didn't unfold, nothing I did would make it start. I thought it was faulty battery but got it tested and all okay. 12volts. I managed to get it started by just flicking lights and things, just came to live. I checked voltage at batted again, still 12 volts so thought alternator goosed. Disconnected the battery over night incase it didn't start first thing. When I reconnected morning and drove it to the garage, explained to the mechanic and he tested voltage at battery and altenator. Both showing 14.4 or 14.5. Day to day now sometimes on starting car comes up with battery charge fault on starting, sometimes stops it from starting, sometimes it just flashes up and disappears.

 

When the engine is running the battery voltage should be approximately 14V. If you are only getting 12V it would normally suggest that the alternator is faulty. However, given that the fault is intermittent and you need to flash the lights to get the car to start may suggest something else is wrong. The first thing I would do is check the battery earths. Make sure there is no sign of corrosion and that they are tight.

On the alternator there should be two connections: a small two pin plug and the main charge cable. Make sure the plug is pushed in properly and the charge cable connection is tight.

 

Hi Ian,
Thank you for the response. I'll have a look at battery earth's and cables on the alternator. May take some time and some research before I go digging about, I'm not so confident under the hood. I have a gut feeling it's wiring or something electrical. I don't think its alternator itself. Just from what I've read and what I see, it could be though. The car is only 4 years old and covered 33000 miles. I've had it since new and serviced regularly. Frustrating me that this has happened. I don't want to jump straight into garages and get charged a fortune just yet.

 

A good battery should measure 12.8V when fully charged. I think the battery earth is the most likely issue. No harm in just looking - for example you may see some white powder where the cable is bolted to the car's body.

BTW If your car is four years old the battery could be on the way out. Mine failed when the car was 3 years old.

Edit
I know you have previously disconnected the battery but I just wanted to check you know to wait 3 minutes after turning everything off and shutting the car door before disconnecting battery.

 

I had the battery tested and it was all good. A friend of mine who is a bit more car savvy took it out and tested it. Results came back that it was all good. Yeah I disconnect the battery after 3 minutes. When it's day light I'll head out and see if I can see anything with the earthing of the battery.

 

When you get your problem are most of the electrics such as lights, windows radio working. If so the problem may be in the BSM (engine fuse box). The BSM is not a simple fuse box it has a lot electronics and relays. If you are losing power to only a few things e.g. starter motor solenoid and folding mirrors it can be due to a fault in the BSM.

 

Steven,
Your problem is sounding more and more like the fault I had. If you look at post 9 of this thread there is a picture of a BPGA with the cover removed - there is a stud visible in the bottom left hand corner of the unit. Post 16 shows a picture of the unit in the car with a temporary link to this stud. Can you locate this stud on the BPGA in your car and monitor the voltage on it relative to the battery earth when the fault is present and when the car is running? The stud may be covered by a plastic cover which will slide out of the way.

 

I recently bought a 2018 plate 3008 GT Line 3 weeks ago which was running fine with no issues but this week it has started to display the same fault as the original post. The fault has all the same symptoms such as wing mirrors not folding out etc... Although the car is 4 years old it has only done 8000 miles, I don't know why this would now appear. The car is going back to the dealership to be investigated under warranty but should I insist that the the battery and the BPGA are replaced or could it just be the battery as I will assume the car did very little driving of the last four years and the battery may just be in a poor condition despite me driving it daily on 50 mile round trips. Also interested if it could be the relay again not being used extensively is failing.

 

Dealership changed out the BPGA and that sorted the problem for me. Battery was fine.