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CB650F 86 error ?

SevenFiftyNL

2017
CB650F ABS
Oct 26, 2019
Hello,

On my 2017 CB650FA my check engine light is burning. It's not always on, but it is mostly now. I brought it in to the dealer, and they couldn't find anything. They said there was an issue with the combination meter. After I brought it to them, however, it gave me an error code; 86.

The issues I'm having are: my tachometer is fluctuating. The engine seems to lack power. Sometimes, when the error isn't there when I start it but appears during driving, I get this power dip. I think engine breaking appears to be less, too.

Does anyone have any idea how to fix this? Can it be that the ECM is bad?

Most importantly; can I continue driving with it? It feels like some sensor is just falling back on some standard value, which I think can't really hurt?

Thanks in advance!
 

Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
Code 86 is a comms error on the data line from the ecu to the dash.

Safe to ride but you may get random readings on the dash... So be alert.

Most likely a faulty dash or wiring fault.

J
 

SevenFiftyNL

2017
CB650F ABS
Oct 26, 2019
check the connection at the cluster to make sure there are no bent pins, corrosion or not seated tight.
So, behind the dash?

You're occasionally losing power also, maybe it is just a poor battery connection?
Not complete power, just, it feels like its holding back. Not as responsive on the throttle until 3k revs.
Code 86 is a comms error on the data line from the ecu to the dash.

Safe to ride but you may get random readings on the dash... So be alert.

Most likely a faulty dash or wiring fault.

J
That doesnt seem to explain the lack of power I experience, though.

Thanks for the answers. Will defenitely check the wiring behind the dash.
 

Brammers

2014
CBR650F ABS
Staff
May 30, 2014
Hampshire, England
The ECU may be entering failsafe depending on it's inputs. I don't recall anyone reporting a code 86 triggering a limp-home mode though.

If power loss is the case (and it's not placebo of the speedo readout changing?), I'd check the connectors on the ECU also for a loose/dirty pin.

J
 

SevenFiftyNL

2017
CB650F ABS
Oct 26, 2019
Also check connections on the battery & battery voltage itself. How old is the battery?
I've had the bike since last year. 6000km, now 16.000. I'm guessing it has never been changed or any fluid added. I meassured it yesterday, was 12.7V. Dropped to 10.5 on keyturn. Went back to 12.7 really fast after start.

The issue hasn't turned up yesterday on the ride back home, or this moening into work. So I'm hoping it somehow resolved itse- ah, who am I kidding, it probably didn't. If it pops up on the ride home, Ill check the wires behind the instruments tomorrow. I really hope I dont have to remove the tank, though.
 
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