Avant 860i not starting

[NickM1984]

Good afternoon everyone. A customer of mine has an Avant 860 which won’t start. It’s used in a quarry as a loader and sweeper. It does live outside permanently in the elements.
According to the operator it just came to a stop one day in torrential rain.

This model has the stage 5 Kohler engine with DPF filter.

Firstly the ignition key wouldn’t even turn in the barrel so I fixed that.
Fuse for the dash display was blown so replaced that. Now display comes on with ignition. At this point the fans would normally come on as part of the starting sequence but they do not.
There is a red warning light on for the engine and fault displayed across top of screen saying ‘loss of CAN communication’.
Only fault code stored on dash display is to do with throttle housing. I have checked throttle and wiring all looks good.
I used basic TEXA to read fault memory and it came up with ambient temperature sensor. These faults could be deleted but after ignition cycle they re-appear. I’m sure that these faults wouldn’t stop the machine starting. Confused and starting to scratch my head I opened up and went through both fuse boards and all relays with nothing obvious found. At this point all plastic panels are removed.
It was very clear that the machine has been rained on constantly for 3 years, when I unplugged one or two connectors and let the looms hang downwards rainwater poured out of the loom shroud. Quite alarming and worrying. So I then unplugged all looms and hung them downwards to drain. I couldn’t see how it was possible to get this much rain water inside the harnesses especially as they are well covered by plastic body panels. Although the wiring harnesses were full of water I couldn’t actually find anything physically wrong. All wires and connectors themselves were in good order. Plugs were dry inside. The owner assured me the machine has not been sunk in a pond and the machine is clean and tidy looking so I don’t think there’s been operator foul play .
Water drained out overnight and connections clean and dry the next day.
Still won’t start.

I’m quite new to the stage 5 Avants and would really appreciate any help or advice. I do have access to full wiring diagrams but honestly don’t know where to start. I have an incling that an ECU may have popped because there’s nothing physical staring back at me.

Thanks a lot guys. Nick

 

[Steve]

My guess is the ignition barrel is still faulty or incorrectly wired.

 

[bobthebuilder]

would it be as simple as a failed stop solenoid ?

 

[6feetdown]

Worries me on mine all the electrics exposed to the elements

 

[NickM1984]

My guess is the ignition barrel is still faulty or incorrectly wired.

Thanks Steve. I did replace the ignition switch complete with a new one I carry in the van, made no difference so I put original back on

 

[NickM1984]

would it be as simple as a failed stop solenoid ?

Because this model runs several ECU’s I don’t think it has a stop solenoid as such. More likely to be fuel shut off and flap motor on this machine. Thanks though Bob

 

[NickM1984]

Worries me on mine all the electrics exposed to the elements

6 feet down. They are built very well but for some strange reason they put some relays at the lowest point of the machine close to the ground. Muck and water can get in between the floor and side panel at the bottom and this can be a problem. If it was my machine I’d remove the panelling annually for cleaning

 

[6feetdown]

6 feet down. They are built very well but for some strange reason they put some relays at the lowest point of the machine close to the ground. Muck and water can get in between the floor and side panel at the bottom and this can be a problem. If it was my machine I’d remove the panelling annually for cleaning

Good idea as ours is in the sh*t with the way the weather is at the moment

 

[V8Druid]

6 feet down. They are built very well but for some strange reason they put some relays at the lowest point of the machine close to the ground. Muck and water can get in between the floor and side panel at the bottom and this can be a problem. If it was my machine I’d remove the panelling annually for cleaning

if it was mine I'd be looking at putting said relays on umbilicals and relocating them up out the sh1t somewhere higher on the machine ... not a great deal of effort to extend them

 

[Mick-the-fitter]

The can error would be a signal from the temp switch to the ECU and on to the cooling fan/s this will stop it starting as a cooling issue, test the fans with 12 v supply, and put the temp switch wiring to earth.

 

[jd6820]

The can error would be a signal from the temp switch to the ECU and on to the cooling fan/s this will stop it starting as a cooling issue, test the fans with 12 v supply, and put the temp switch wiring to earth.

Yeah I'd agree with this ^^^

Worse thing you can do sometimes is assume that fault codes won't stop it running. I had a road sweeper with a VW engine in recently. Was going to ask for help as I couldn't see anything majorly wrong with it apart from a fuel leak on leak off side and a glow plug error. The thing would start and run no bother but die as soon as you asked for revs. Another person attended the machine before me and failed. I went back to basics and solved all the problems I could see. First the fuel leak and finally a glow plug in cylinder 3. Cured it instantly. Had I ignored the glow plug code thinking it runs well without heat I'd have been ages fault finding. It didn't even have a de-rate code, which you'd have thought it would have to cause a stall as soon as the engine rpm increased above 1500.

 

[NickM1984]

The can error would be a signal from the temp switch to the ECU and on to the cooling fan/s this will stop it starting as a cooling issue, test the fans with 12 v supply, and put the temp switch wiring to earth.

Like your thinking Mick. Do you know the Avant 860 model? I had trouble identifying where the ambient sensor is located. Stupid question but is it mounted above them engine on the cooling fan bracket? It has a pipe plumbed into the air filter housing

 

[jd6820]

Don't know anything about Avants but it might be worth checking CAN voltages, to check they are within spec as you could be getting codes that mean nothing. Especially if a controller is broken and influencing CAN lines or a faulty terminator. Check CAN Lo is running at around 1.5 - 2.5 and CAN Hi is 2.5 - 3.5. The combination of both voltages should be 5V which is TTL voltage.

Also the ambient temp sensor could be combined with MAF or MAP sensor?

 

[Mick-the-fitter]

So basically the CAN is the eyes and ears, the engine and cooling system will work separately until there is a fault, then the ECU will via the CAN let you know about it, like a book ( the error code could be a misspelled word, in a sentence, in a paragraph, on a page, in a chapter, in the book! ) so the CAN will send 6 error codes, one for the spelling, one for the sentence it’s in, one for the paragraph, one for the page it’s on, one for the chapter, and one for the book! So the book being the ECU. Fix the spelling!! You have the whole story!

Take some pics of the cooling system ie water pump, thermostat, fans and radiators.

 

[NickM1984]

So finally got the machine recovered to my workshop.
We had an identical model Avant so I thought I’d swap a few bits over to try and eliminate certain things. I changed over the dash control unit, the engine ECU and body ECU. Neither made any difference.
While fettling in the main fuse/relay board (with ignition on) the cooling fan for hydro-radiator magically came on. And with ignition switched off this fan continued to run . But with a wiggle of one relay in particular the fan switched off. Another interesting note is that the intercooler fan doesn’t run. Now when you first switch the ignition on both fans come on briefly on these models.
Curious- I completely swapped over the whole fuse/relay board with the good machine and tested.
Now with the ignition switched on the hydro fan turns on for a timed period (the intercooler fan still didn’t) but the engine still wouldn’t turn over and start. And the same dash faults and error codes were displayed.
Had some ‘technical advice’ from Avant who just said there must be a loose connection . (There isn’t)
Switched original fuse/relay board back and the fault followed.
I think I’ll need more time on this one

 

[NickM1984]

NOTE: I stripped the fuse board down and checked all connections and integrity of the board with nothing obvious wrong at all

 

[GazCro]

There isn't a bad earth somewhere, may not cure all the faults but could be some. Sometimes not obvious as can earth through something else (i was told of a forklift which had a broken earth which was never noticed as it must have been earthing through the brake pedal which was never used until somebody pressed it one day and forklift stopped working).

 

[Mogman]

I’ve had a plug with an earth pin not making a proper contact once did strange things to the ride on mower

 

[NickM1984]

Cheers guys .
I had made up new earth strap for engine and battery. And re-did one earth point with 4 earths on it. There may be more.
It does have that ‘back to basics’ feel about it for sure