Erratic intermittent fault

Ok,having electrical problems on my 2006 315 Sprinter-

First it started with the rear cargo and sliding door not locking throwing a dash door open symbol,checked all the pins etc and doors were shutting fine.At this time I wasn't getting the indicators flashing on the lock/unlock process.

It would stay this way then drive a few miles and clear itself until it actually stayed with the fault permanently.

I decided to take it to an independant who has star diagnostic today to get it checked out,en-route it actually cut out 3 times,the radio went off and stayed off during the flashing fault/warning light process so I decided to take it back home.While driving the engine light remained on and the door open symbol.

I fitted a Dynavin aftermarket Nav/headunit about six months ago and its been fine apart from a couple of times the screen would go off but radio still play,removing it and powering back up restored it.I asked the vendor for advice and he suggested by passing the can bus black box unit that was supplied with the unit.

Anyway,I decide to remove the unit completely as the radio turning off just as the engine stalled made me think it could be creating the problem somewhere and I also had GPS issues.

So, I removed head unit and fitted another GPS which instantly fixed that issue,then fitted everyting back together,van started fine and locks are now working along with the flashers working on lock/unlock!

I can only assume it may have been a wire grounding out or the supplied canbus box supplied with the head unit.

Thoughts or anyone had these gremlins?

On a side note,I washed the van yesterday and got soaked with it leaking through the roof/windscreen today but thats for another thread

Whatever you removed (Can Bus related) fixed the problem, but it sounds like it was just a patch.

Kind of like tearing off a band aid before your scab is fully healed. Unfortunately in this situation the wires don't heal themselves afterwards.

Any way to go back to the section where the radio tapped into the CAN bus and clean that section of wiring up?

I was thinking the same thing about the Can Bus-checking the connections to the head unit you took out, thinking that someone may be jacking with the communications on the bus.

Does anyone know if the audio/nav system resides on the same bus as the locking system? Seems Jon C posted a picture of the bus system(s) some time ago, I'll dig around a little

Wow....I found the document from long ago, it is titled "Sprinter Overview Part 1.pdf", it has an absolute wealth of knowledge about the van even down to how to integrate new wheel sensors to the TPM and voltage supply wiring diagrams! This may have been a Body Builders document. I'm having trouble locating it in the NCV3 forum though....anyone??

added: The Central Locking system uses the I-CAN (assuming it stands for Interior Can Bus) but also utilizes the SAM for disseminating commands to the individual doors, identified as M14/27, M14/7 and M14/28. A note states that each cargo/sliding door contains a door contact switch and lock switch.

Sorry, but I can't figure out how to copy a single page from the PDF and share it with this post

72chevy4x4 said:

Sorry, but I can't figure out how to copy a single page from the PDF and share it with this post

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You either have to print that one page to a PDF printer (something like CutePDF.com needs to be installed) or you do a screen capture, but you will have to edit it in a picture editor. The former one is easier.

If the file is here, maybe someone knows what it is.

Thanks guy's,a bit of light at the end of the tunnel.

I havn't removed anything yet but the vendor did suggest removing the supplied canbus digitiser box,as he called it and wire it to a constant,switched and negative to the three wires leading off it.All I basically done was the take it out and reinstall.

Be good to see a schematic to see just how the two are linked and if it actually was linked to the stalling issue.

I did ring the main dealer asking about the leaking roof issue but he mentioned no recall was available and the first time he'd heard of issues but he did admit to wiring woes on the NVC3 that were constantly causing the workshop some headscrathing.

here's a great read to initiate oneself in the understanding of the Can-bus


http://www.vehicleservicepros.com/article/10329448/sprinter-electrical-systems

Thanks for that

Little update!

I narrowed the cutting out to the battery connections being loose!

It stalled again today and the whole van was locked out,no power at all and with my tools being in the back of the van it was one of those lucky/unlucky moments when the rear was totally locked!

Managed to borrow a few tools of a passer by,tightened the battery and removed the head unit,all was well,started no problems,drove home,no warning lights no issues.

Left head unit out completely and restarted,rear doors wont lock,flashers only signal on unlock but not lock,driving me round the bend!

Ok, it settled down after I removed the can-bus digitiser for head unit,sort of for a few days then the same problems have returned! It seems to come and go if I go over a bump!

Also,the battery light on dash remains on,tested battery at 11.4 volts and the same when engine is on,not good!

To cap it all off,water ingress inside cab is getting worse,seems to drip from roof windshield area,water and electronics is never a good mix!

I've searched on here for a good few hours and theres so many possibilities it could be

gwc said:

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Also,the battery light on dash remains on,tested battery at 11.4 volts and the same when engine is on,not good!

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There have been quite few low voltage conditions which have been traced to poor connections in the heavy cables related to the starter/battery and sometimes common ground points. Be careful to not get so caught up in the more exotic possibilities that you ignore the more basic ones.

There were some good guides as to how to check those cables/grounds using a basic voltmeter. A search from the blue bar above should find those threads. Good luck. vic

Yeah,I stumbled across those,thanks.

It looks like the "Y" cable is the first port of call and the 300 amp fuse near the bellhousing.

I briefly looked under the van tonight and everythings covered in oil,looks like a decent leak from somewhere!

I'm beginning to hate this van with a passion......

Ok, charged the battery up this morning,it was reading 11.4v after an hours charge 12.4.

Started her,battery light off, put lights on and a/c battery light came on.

Shut everything down,scratched head and had a coffee.

Started her back up,battery light off,lights and a/c back on still no battery light!

Tested voltage at battery with rpm at 1500,14.5v!?

Everything works ok now,doors lock no warning lights!

I'm beginning to think maybe ECU or water related problems,is there anything overhead or dash area that can be affected?

It was wet under the carpet last night as I removed the battery access hatch on the floor,it seems to be getting behind the dash and running down.

It rained yesterday but its dry today and all seems dry in the van.

I don't know this for a 'fact', but would say that water in a vehicle w/ a Canbus system would be a bad thing if that one connection that is wet goofs up that entire bus system b/c the system thinks it is a short condition.

Better make sure the water leak is no more!

It cant be a good thing

I think a lot of it a while back was condensation,van had stood a while and I took it out and I was literally soaked with water from above as I went downhill!

I'm away to get the codes checked at an Indy hopefully they've been stored on the ECU.

Just back from the Indy,lots of faults stored under voltage drop,apparantley its a lin-bus system using one wire?

Was told alternator coverd in oil is really bad and a common fault on Mercs,new one needed?

Thoughts before I blow $600?

BTW,all seems fine now!

gwc said:

Was told alternator coverd in oil is really bad and a common fault on Mercs,new one needed?

Thoughts before I blow $600?

BTW,all seems fine now!

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Oil soaked alternator is most likely not a good thing: but before spending $600

You could remove the alternator, disassemble, clean, check the brushes etc reassemble, and while your there, clean and double check all the alternator, starter, battery and fuse box connections

Gave the engine bay a good clean out and also attended to some pretty nasty paint blistering/rust spots on the body.

Things seem ok on the alternator front,battery is fine and charging,no battery lights.

Rear locks are still playing up and dash light comes on if I go over a bump then off if I go over another!

I'm tending to think because the front doors are ok it may well be an issue with the sliding door showing open?

I've searched but cant find a definitive answer on where the sensor/strike plate is on the sliding and rear doors that flags the door open light up?