Lots of errors!!!

[T6_FunBus]

Greetings.

I’ve recently had the orange coil light flash up on start and a stop start error.

On checking I had the following errors:

P064C00 - Glow Plug Control Module
P172400 - Signal for starter lock, short to ground

I cleared these a couple of times and would run fine and but now they are back and with more errors!:

03046 - Battery Regulation control module, no signal / communication
02252 - Generator, no signal / communication
03158 - Information Electronics Control module 1, no signal / communication
U01400 - Lost communication with body control module
03022 - Local databus 4, error in electrical circuit

Most are clearable, apart from Signal for Starter lock.

Not really sure where to start. The battery is charging, and was replaced and coded (new serial entered) earlier this year. Van starts and runs fine apart from stop start is disabled when the signal for starter short to ground persists, sometimes that will clear and no errors and stop start works fine.

Could this be the green / yellow lin wire look damage people have reported before?

Any other suggestions on where to start?

Thanks.

 

[T6_FunBus]

I took a look this evening as it was dry(ish), I cannot see how I could possibly get to that green and yellow wire, as it does not go around the back and down like shown on some transporters. It goes down into a corrugated pipe and vanishes under the plate under the battery mounting tray, and try as I might with all of the other crap and hoses, pipes and wires around there, I cannot see any route down, in fact, looking at the plug on the alternator which is barely visible, it buggers off under the engine on that end.

So I pulled the two wire electrical connector on the BMS, and no new errors, but all the same errors as before after clearing. So given it resulted in the same errors (including no signal from BMS, which I get when it is or is not connected), I would take a guess that either the BMS is faulty or the signal from the BMS is screwed, so a broken wire in the loom.

Not knowing 100% how the BMS effects other systems if the ECU is unable to read battery voltage, perhaps it is feasible that there is a grounding issue through this unit / cable causing intermittent issues with the other modules failing. It has to be intermittent though (only seems to appear on ignition on according to the error timestamps) as the van then starts and works OK.

So plan of attack is either get it in to someone I trust to check the loom, or source and fit a new BMS with cable. Which in itself does not appear simple, as I cannot find any new part online for 7E0915181K. So probably a long wait from a VW dealer and my pants being pulled down by them...

 

[T6_FunBus]

Found them. Wires look good, so I’ve put them back.

 

[T6_FunBus]

Well, I decided to disconnected the starter battery, so that the BMS is disconnected totally. I Cleaned up the BMS terminals and re-attached.

I had the following errors return (did not start engine) with ignition on apart from the addition of 'low battery voltage':

Engine ECU module 01
P056200 - System voltage, low voltage (unable to clear, battery was at 12.8 volts when reconnected according to my voltmeter, but did drop to 12.4 with ignition on while reading codes)
U01400 - Lost communication with body control module (unable to clear)
P064C00 - Glow Plug Control Module (cleared)

BCM module 09
03022 - Local databus 4, error in electrical circuit (cleared)

The two persistent errors I am unable to clear with OBD11 or Autel Maxi are P056200 low voltage and U01400 - BMS communication error.

Not really sure what this means at this stage...

Seems a coincidence that I get a bunch of other issues like the ones in the original post coming back too after a run.

 

[T6_FunBus]

Ahh yes, also checked fuses for BCM, ECU and BMS.

 

[T6_FunBus]

Had another look today, still no further forward really. Battery voltage still seems OK. high 12's, going to 12.3-12.4 with ignition on.

Van starts OK, all the same errors above come back though as soon as cleared.

Two persistent errors I can never clear are the low voltage error (even though voltage is not low) and BCM communication.

Live data shows battery voltage, and alternator kicks in just fine and starts to charge battery.

Battery control module always comes back with two errors as soon as I clear too:

03046 - Battery Regulation control module, no signal / communication
02252 - Generator, no signal / communication

I have looked everywhere for replacement 7e0915181K - seems like hens teeth, just some second hand overpriced parts from Germany.

Does anyone have any idea how to test the Battery Control Module before I attempt to replace (if I can even find the part anywhere!!).

As I said before, disconnected the plug on the Battery module doesn't give me any new errors, still the same old ones above.

Thanks.

 

[T6_FunBus]

I went back out this eve and decided to fully expose the lin wire from the alternator up to the bottom of the battery tray. It was pretty much fine, there are a couple of small indentations in the wire in a 1cm section, but the casing hasn't been broken, and wire seems to be fine.

I am starting to think it is more likely the Battery Control Module. That lin wire goes into that module, so if it has failed, then maybe its the cause of that error and the others.

 

[T6_FunBus]

At this point I am just talking to myself lol, but figured I may as well document it in case it helps any others:

I bypassed the lin wire from the alternator to the battery module, and connected it direct to the battery module with a new wire.

Same faults.

Tested 12v at red battery control module wire, OK (battery voltage)

11v direct from alternator to battery control module

11v on bypass wire

Disconnect battery control module = same 5 faults

14.3 volts when van started.

10.3 on original lin wire from alrernatior.

I’ve cleared the errors a bunch of times but the three that always persist are:

Lost coms with Body Control Module
No signal battery regulation control module
Information electronics control module 1 - no signal

I don’t know what else I can do to test the battery control module. The lin wire from the alternator shows a lower voltage, so maybe I should fit a new one just in case of future problems, but that doesn’t appear to be the issue here.

Given I get the same faults if the battery module is disconnected or connected, and the lin wire and +12v have been tested, maybe it is the battery module?

Would that cause the constant BCM error and start stop error?

 

[roadtripper]

Your errors are communication errors mostly - have you traced the canbus wiring for any faults?

If the state of charge of the battery isn't known then I would expect start stop to be disabled, that's a symptom not a cause.

 

[T6_FunBus]

The only wire I’ve checked is the one from the alternator to the battery control module.

If I go into battery management it shows the battery voltage, but the alternator and module shows starus of zero, I think it should be 1? Makes no difference if I bypass the original wires and fit new one direct.

 

[T6_FunBus]

Update, even though this does not appear to be my problem, I am thinking of removing the lin wire from the alternator plug and fitting a new one from the alternator to battery control module, as the old wire shows 10.3v @ idle from generator on wire, wheras I have read it should be 11 at rest.

Does anyone think this is a good / bad idea?

I am thinking if the original wire is already showing a lower signal, this may indicate the wire is breaking down inside somewhere, and so to prevent future issues with this wire, perhaps it is better to replace so there is a cleaner signal before I put the wiring back?

Also, does anyone have a negative wire / shunt / battery module spare that I could try to rule this out?

Thanks.

 

[T6_FunBus]

One more question if anyone can answer.

Is module 61 the battery control unit on battery? Part no / hardware in diagnostics shows the BCM part number???

Trying to figure out the difference between these two error messages, one was in gateway other module 61…

Are they talking about the same thing?

 

[T6_FunBus]

New wire installed

 

[Lightrofit]

Module 61 Battery regulation control module is a sub section of the BCM, just like the Gateway, so it's built in to the BCM itself instead of being a separate module.

If you're getting Comms issues with the alternator and you're confident the LIN wire between them is fine then I'd look at maybe a BCM... But this is a really unlikely solution as the BCMs generally don't go bad in this way.

Another thing it could be is the voltage regulator on the back of the alternator itself. Way more likely.

What's your engine code?

 

[T6_FunBus]

Thanks, its a CXHA.

Since fitting the new wire it shows 10.9 volts, not quite the 11 at rest directly connecting the meter to the terminal show, but better than 10.3.

Routing it and wrapping with original loom was fiddly but all done. I cut the plug off and connected the new wire right from the plug all the way over to the battery module.

Now I have stop start error on the dash, sporadic glow plug control module error (clear and restart, then will go away when engine warm and restarted).

BCM lost communication error persists.

Generator and battery errors gone and touch wood haven’t come back after cycling ignition and several stop and start cycles.

I’ll use the van tomorrow and see if they stay away or come back.

But now still need to sort glowplug module error and bcm error. Then hopefully stop start error may resolve.

Thanks.

 

[T6_FunBus]

BCM error remains after a drive, still can’t clear that.

Glow plug error from cold start.

Battery regulation error (clears).

Oddly obd11 showed a low 11.4 this morning on starting. I checked the battery last night and this morning and at rest before unlocking and turning on the ignition it was 12.7.

 

[roadtripper]

12.7 is around 85% SoC for an AGM - so that's in the expected area for a start stop system.

You still might have an issue with the battery not being able to supply enough cranking amps if the voltage dips dramatically during start. Do you know how old the battery is?

 

[Lightrofit]

BCM error remains after a drive, still can’t clear that.

Glow plug error from cold start.

Battery regulation error (clears).

Oddly obd11 showed a low 11.4 this morning on starting. I checked the battery last night and this morning and at rest before unlocking and turning on the ignition it was 12.7.

Has any of the wiring at the BCM been altered? Like for MFSW retrofit or alike?

 

[T6_FunBus]

12.7 is around 85% SoC for an AGM - so that's in the expected area for a start stop system.

You still might have an issue with the battery not being able to supply enough cranking amps if the voltage dips dramatically during start. Do you know how old the battery is?

True, this morning after cranking it dipped to 11.3 for a while! Battery replaced Dec 2022, I try to keep it on a stop/start laser trickle charge in maintenance mode when not in use.

Weirdly the errors (not glow plug / stop start as that was already there) appeared after leaving it on trickle charge and the van sat for two weeks while on holiday.

Has any of the wiring at the BCM been altered? Like for MFSW retrofit or alike?

Yes, BCM wiring and coding modified, ccs wired to pin to com with lin bus, but that was over a year ago, and no bcm faults etc until recently. CCS etc still all works fine.

I am going to order a glow plug control relay today I guess in an attempt to resolve that error.

 

[T6_FunBus]

Had a low voltage glow plug cylinder 3 today, Thats a new one, could be related to the glow plug module being faulty or battery low I guess.

I could put the battery on a charge cycle - I have had the ignition on and off a lot recently without moving so could be quite low.

I did read if charging to use chassis / earth strap connection and positive, NOT directly to positive and negative as it will confuse the battery module - is there any truth to this does anyone know? This is my first stop-start vehicle, I have always just connected the trickle charger straight to the battery terminals. The only change I made was to get a ‘stop / start’ specific charger for yhe van.

Glow plug module ordered from VW (thanks @Lightrofit for part info). I’ll get that fitted tomorrow eve / weekend and see if it resolves the glow plug module errors on cold start.

While running the van though to work today I had the BCM error, glowplug module error and battery regulation module error.

On the way home I had glow plug culinder 3 low volts and BCM, battery regulation module etrot cleared.

If I can solve the glow plug thats one down, then on to BCM, then I guess battery regulation if it keeps coming back. The battery was charging at 14+ volts to work and back.

One confusing thing is the ‘stop start’ error on dash even with no glowplug error or battery error on warm start. There is nothing there other than BCM. I assume some parameter that needs to be met is reported as bad, and preventing it from opperating, example voltage too low, or so its disabling the system but not reporting an error.

Cheers.