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CBR650F Engine light problem

JMCBR

2014
CBR650F ABS
Feb 14, 2018
United Kingdom
Hi all; I think I'll probably need to get a mechanic to diagnose... but wondering if anyone else has experienced anything similar or has any advice as the stealership wants over £100 just to diagnose.

Here are the problems:
Indicators stopped flashing and stayed solid at the beginning of last week - put this down to a faulty relay but haven't got round to replacing this yet.
Towards the end of last week, I got false neutral and red lined - then slipped into lower gear. This put the engine light on and then indicators didn't work at all (I presume it may have finished the relay off?).
The engine code flashes 8-6 on start up and stays solid whilst riding (I believe this is a serial communications - PCM to cluster code).
I have noticed that the bike now doesn't pull as well when it's cold (dip in response/acceleration) from throttle until it is warm. The engine feels and sounds normal, particularly after it's warm - but it certainly isn't as responsive when I've just started it and ride off.
I'm hoping it'll be something as simple as the indicator relay - could this cause a PCM to cluster engine light code? Maybe a dodgy battery (it's not been replaced since I owned the bike). Is there a way of diagnosing myself?
Thanks in advance!
 

JMCBR

2014
CBR650F ABS
Feb 14, 2018
United Kingdom
I guess I will keep adding info so if anyone else finds themselves in a similar situation and finds this thread it could help.
Checked the battery using a tender (don't have a multimeter) and no error lights given. Left it to charge overnight and no difference - engine light still persists. I don't think it's a battery issue.
I have suspicion that the MAP sensor may be involved as the revs drop when I twist the throttle until the engine is warm. No lights to indicators. I will replace the fuse but I need a new relay fitting first and see if this solves the problem (I doubt this is all being caused by a faulty indicator relay though). Then I'll move onto the MAP sensor/check tubes and wires there. If no improvement I'll have to get myself a multimeter and start checking the ground wires.

Does anyone have any information on where to find the grounded wires?
 

Devilsfan

2018
CB650F
Jun 5, 2019
Tampa, Florida
Don't be surprised if it is your battery! I've had some weird operations on a Honda with a bad battery. Using a battery tender is not "checking" the battery.

I'd suggest taking it to an auto store and have them load test it. Most auto stores here in the USA test these for free, they just roll out their machine to the parking lot. Your bike is a 2014 so it's probably close to a battery change anyway.

A few years back my Honda CTX battery went low. Push started it and got the bike running, got home and hooked it up to the battery charger overnight. Charger said "Green" in the morning so I took it to get load tested. Even they said it was fine. One day later...dead again! That's just a bad battery! And that was only 2-3 years old with hardly ever used for charging cell phones and gadgets.

Point being, batteries can go on you after a year or two. They can also last for 5+ years! But when they go...they go! So unless you did something to the wires or installed something I'm thinking your battery is about dead.
 

JMCBR

2014
CBR650F ABS
Feb 14, 2018
United Kingdom
Thanks for this.
The indicators not flashing (staying a solid light) and then not working at all (not on the dash either) is likely just a coincidence, right? A dud battery wouldnt stop the indicator relay from doing it's job over other things?

edit: the fact that the dashboard 'resets' once the ignition is off makes me suspicious that it has something to do with the battery too? (the time is reset to 1:01 once ignition is off and restarted - and it automatically displays mileage, even though I set the default display as being mpg). The only thing I'm wondering is why the throttle response is poor until the engine warms up... this seems like a foul spark plug? Could this have happened because of slipping into a low gear/forcing a a sudden red line?
 
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Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
A dash reset with no engine running is definitely a battery power related issue. It might not be battery itself - it could be the connections to it. As the bike starts fine, that would indicate enough power is present to crank the bike though.

Could be a intermittent connection with the dash. Grab the service manual from the resources section, and follow the procedure to display the MIL code. That will give you a big clue as to what is going on.

J
 

JMCBR

2014
CBR650F ABS
Feb 14, 2018
United Kingdom
Do you mean the flashing MIL on start-up? That reads as 8 long and 6 short - PCM to cluster serial communications error. It then goes solid whilst riding
 

Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
Yes. Sorry I missed that line in your post.

Check the wiring loom between the ECU and the dash for breaks or worn-through cables that could be shorting.

Is water ingress a possibility? Riding in rain/washing the bike etc.?
 

JMCBR

2014
CBR650F ABS
Feb 14, 2018
United Kingdom
I will check when I get home and update (I presume this loom is found under the tank?).

That’s certainly a possibility - I commute on it in all weathers and last week was awful for rain. Although I’m guessing it would have dried out by now? Could this have caused the indicators to stop working too if it was water ingress near the dash?

edit: just as we speak of rain the British weather has not failed to disappoint. I have never seen rain so hard in all my life... I'm hoping it stops before I set off home as it may finish my bike off!!
 
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Rtw6095

2015
CBR650F ABS
Dec 20, 2018
I have had this 8-6 code before. Same symptoms as you (minus the indicator problem) had the dealer replace the Throttle Positioning Sensor. Never had the same issue again.
 

Rtw6095

2015
CBR650F ABS
Dec 20, 2018
Dealer said the 8-6 was a stored fault. Unfortunately I cannot remember if he told me what it was for.

My throttle positioning sensor was brought up by a couple of work colleagues who have many years on bikes saying it sounds like it's faulty.
 

Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
While 8-6 isn't a code listed in the service manual, 8-anything are TP sensor faults.

So you are on the right track. Maybe get the sensor checked (or check it yourself) for comfort.

J
 

skeletor

2015
CBR650F ABS
Dec 13, 2018
Don't forget, according to the manual 4-7:

-you cannot determine the sub code from MIL blink pattern(digits after hyphen), you need the MCS tool to read that
-the blink pattern is used to indicate the main code only(digits before the hyphen)

If there was an 8-6 code, you would only see 8 short blinks on the MIL
 
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