Has my ECU / BMS died?

[Aus23]

Hi All,

New to here ... I've a 2002 F650 Dakar, previously running perfectly. Over the recent cold spell, the battery started struggling so assumed it had done its time. I got a Mottobatt, fitted it, and it started perfectly, ran it for 2 mins and left it. Next morning, went to start it and noticed when I turned the ignition on, I didn't get the coolant light coming on. It cranked over healthily but wouldn't fire.

So I've checked/looked at:
- all electrical plugs/connections to see if clean, attached
- no obvious wire breakage
- by-passed the side-stand by 'shorting out' the connector plug
- the kill switch does seem to be working i.e. if I switch it off, it doesn't crank
- there's no immobiliser or ABS
- power is getting to the ECU
- I've removed the ECU and disconnected the battery, left overnight
- I've changed the starter relay
- all fuses good
- I don't hear the fuel pump come on when I turn the ignition on, but direct power to the pump and it works fine

I borrowed a GS911diagnostic computer checker thingy and it was "unable to connect to the ecu - please check ignition is on/immobiliser is off/kill switch is off/side stand up".

Now I'm not a mechanic so struggling as to what to look at now. I've taken the casing off the ecu and the circuit board looks OK i.e. no obvious shorts; little bit of corrosion around pins 28/27/9 but fairly slight.

I'm guessing that the ECU is not activating when ignition turned on ... ? But gather it's very unlikely for them to fail.

Any suggestions - am pulling my hair out!

Thanks

 

[ahebron]

Got a similar problem at present with 2000 F650GS.
If I flick the decompressor lever on the end of the exhaust cam on the first rotation while starting she fires up and runs well. If not it just wont fire.
But did you check for a spark? Pull the plug and earth it to the frame/engione then hit the start button
Can you see fuel misting into the throttle body.
Is the neutral light on?

Good luck
Adrian

 

[hogfarmer]

I feel your pain , I have a 05. F650gs not a Dakar , but I expect the same as yours in this prob ,no temp light flash to say bike is ready to go, but engine spins over on button, like you I have checked your list and got nowhere. My prob has developed after a long layup so I'm looking for bad connections chewed wires or something. I feel that there maybe a relay that controls the ecu, but like you I don't know my way around , hopefully someone who does will be along soon.

Hi All,

New to here ... I've a 2002 F650 Dakar, previously running perfectly. Over the recent cold spell, the battery started struggling so assumed it had done its time. I got a Mottobatt, fitted it, and it started perfectly, ran it for 2 mins and left it. Next morning, went to start it and noticed when I turned the ignition on, I didn't get the coolant light coming on. It cranked over healthily but wouldn't fire.

So I've checked/looked at:
- all electrical plugs/connections to see if clean, attached
- no obvious wire breakage
- by-passed the side-stand by 'shorting out' the connector plug
- the kill switch does seem to be working i.e. if I switch it off, it doesn't crank
- there's no immobiliser or ABS
- power is getting to the ECU
- I've removed the ECU and disconnected the battery, left overnight
- I've changed the starter relay
- all fuses good
- I don't hear the fuel pump come on when I turn the ignition on, but direct power to the pump and it works fine

I borrowed a GS911diagnostic computer checker thingy and it was "unable to connect to the ecu - please check ignition is on/immobiliser is off/kill switch is off/side stand up".

Now I'm not a mechanic so struggling as to what to look at now. I've taken the casing off the ecu and the circuit board looks OK i.e. no obvious shorts; little bit of corrosion around pins 28/27/9 but fairly slight.

I'm guessing that the ECU is not activating when ignition turned on ... ? But gather it's very unlikely for them to fail.

Any suggestions - am pulling my hair out!

Thanks

 

[squibb34]

Can't claim expertise with the old F650, but I have heard of many cases of Motobatts being installed with the polarity reversed, as they are generic rather than model specific. Does all sorts of strange things. Please, no disrespect intended, loads of seasoned riders have done this.

Otherwise I would be looking at the neg/earth points all around the bike. Clearly you have power to the starter, but not elsewhere. Check all the significant fuses for power & continuity. In the meantime, I Suggest you leave the ECU alone if possible at this stage, but bow to expert model specific opinion.

 

[Aus23]

Hi and thanks.

Am wondering if my new Motobatt has caused some sort of problem.

Have check the BMS and load relays and both are good. Have taken the cover off the BMS and there is power to the BMS with the ignition on.

Wii search out earths to see if these reveal anything (must say, I've struggled to find them at the moment and I've lots of the fairing off!) ... just odd how it started great one evening and then, overnight without being touched, has become lame!

 

[Dansin]

I don't hear the fuel pump come on when I turn the ignition on, but direct power to the pump and it works fine

You should hear it prime when you turn the ignition on. Fuel pump relay is under the plastic triangle under the battery. Check you have 12v at the pump when you're cranking the engine.

 

[Dansin]

I feel your pain , I have a 05. F650gs not a Dakar , but I expect the same as yours in this prob ,no temp light flash to say bike is ready to go, but engine spins over on button, like you I have checked your list and got nowhere. My prob has developed after a long layup so I'm looking for bad connections chewed wires or something. I feel that there maybe a relay that controls the ecu, but like you I don't know my way around , hopefully someone who does will be along soon.

If the fuel pump primes, have you tried pulling the injector and cranking the bike to make sure you have fuel there?

If you really think the ecu has died (unlikely) I have a mate in Osbaston who I could give my ecu to next time I see him for you to try.

 

[Dansin]

Another resource for you both to look at - http://www.f650gs.crossroadz.com.au

 

[hogfarmer]

Thanks for that, I haven't got far with this yet, got to get a new battery, and then start really looking, does the ecu have its own relay? I had similar prob on my Harley a while ago and it was just a relay, 12 quid fixed it. The bm has been at the back of the shed for a couple of years, since my son went off into the big wide world. Time it was fixed and used or sold.

 

[Dansin]

Wiring diagram may be of use to you both - http://www.bmwgs.cz/dwnl/f650gs/F650GS schematic.pdf

I pretty sure all of the relays are under the triangle described above.

 

[Dansin]

I borrowed a GS911diagnostic computer checker thingy and it was "unable to connect to the ecu - please check ignition is on/immobiliser is off/kill switch is off/side stand up".

Now I'm not a mechanic so struggling as to what to look at now. I've taken the casing off the ecu and the circuit board looks OK i.e. no obvious shorts; little bit of corrosion around pins 28/27/9 but fairly slight.

I'm guessing that the ECU is not activating when ignition turned on ... ? But gather it's very unlikely for them to fail.

Any suggestions - am pulling my hair out!

Thanks

If you really think the ECU has died, I'm pretty sure Motorworks would have a secondhand ecu for your single spark bike. You could ask them if they'll sell you one on a sale or return basis, which would allow you to eliminate it as the potential fault.

 

[Aus23]

Thanks - further checking suggests:
- my load relief and BMS relays are OK (i.e. open circuit without 12V, then resistance with 12V directly applied - guessing this means they're ok)
- 12V is getting to the BMS as Ive taken the case off and can check via pin 28
- applying 12V directly to pin 27 immediately kickstarts the fuel pump, and there's fuel squirting down the line
- a visual look a the wiring suggests it's pretty clean, still well wrapped in tape, no obvious damage
- from what I gather, ECUs seldom fail

What to look for next!?

And thanks for the help - much appreciated as I'm pulling my hair out

 

[Dansin]

Sounds like you could well have a dead ecu. £125 for a used one from Motorworks - https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=10&M=65&Ct=HA&SbCt=BA_10_65_HA_85

 

[hogfarmer]

Well, I had a poke around under the plastic triangle, and as you say relays are there so have cleaned and wd40 everything in sight. Hope a new battery will arrive tomorrow, have had a quick go with jump leads, still no flashing temp , I think I will get a new relay as it should be cheap to try. Can't help thinking that the act of changing the battery could have disturbed something in or around the area under the plastic triangle on aus's bike, lot of wires in there. Looking forward to hearing what fixes it for you.

 

[Aus23]

hogfarmer - keep me posted. I tested my relays and they seemed OK but maybe there's more to them than meets the eye! I'm going to take my ECU to a BMW independent and hope he might try it on another bike to see if it's fried or not ... otherwise, I think I might have to buy one as per Dansin's advice. All I can think is by fitting a new battery, for some odd reason that process has damaged the ECU.

 

[hogfarmer]

I suppose the alternative could be there was something wrong with the ecu that killed your old battery , any current flowing when it should be off?

 

[squibb34]

hogfarmer - keep me posted. I tested my relays and they seemed OK but maybe there's more to them than meets the eye! I'm going to take my ECU to a BMW independent and hope he might try it on another bike to see if it's fried or not ... otherwise, I think I might have to buy one as per Dansin's advice. All I can think is by fitting a new battery, for some odd reason that process has damaged the ECU.

Are you absolutely sure about those side stand & clutch switches - we had a baffling issue with an 800 twin on here recently, where the poor guy went all around the houses, thinking the stand switch was OK .... when it had failed.

The bike has be laid up, the switch could easily be corroded within; as could the clutch switch, although it would be easy enough to jump this. From the wiring diagrams, I see the sidestand switch talks to a relay, but I am not sure how you tested the system from your previous notes.

 

[hogfarmer]

Got it running! Ordered a couple of £5 relays to try ,and got new battery today, before I put in I just went round all the connections again with wd40. Didn't even put battery in just jump leads. Switched on and bobs your uncle. I hate electronics, give me an old fashion diesel any day . Good luck with yours aus. Ps my side stand switch has been removed before I got the bike.

 

[Aus23]

hogfarmer - great news albeit I'm deeply jealous!

Squibb - I think I shorted out the side stand switch at the plug (joined 2 of the 3 wires (not the red one from memory)). Clutch switch ... any clues as to what to do/look at with this one.

I also have just checked that there's 12+V at the BMS relay going in to it, and then out of it.

Should I buy some replacement relays just to check?

Aghhhhhhhhhhhh!

 

[DrFarkoff]

Take it to someone who knows what they are doing!

It will be cheaper in the long run!

actually telling folks where you are in your profile could aid assistance