CB650R CB650R DTC P0300 (Random/multiple cylinder Misfire detected)

[User23]

Hello everyone,

I have a CB650R model 2021 with a critical issue in a specific RPM range ( 6000 RPM to 8000 RPM) , the Malfunction Indicator Lamp (MIL) turns on and the DTC code is P0300 (Random/multiple Cylinder Misfire Detected). The motorcycle enter in a restriction mode and doesn´t allow us to increase RPM more than 4000RPM. We have already changed the A/F, MAP, ECT, CKP, rear wheel speed sensors and the PAIR CONTROL SOLENOID VALVE, ECM too.

We haven´t fixed it yet. We want to know if someone have presented this problem and solved it.

Best regards.

 

[Ian Warren]

Hello everyone,

I have a CB650R model 2021 with a critical issue in a specific RPM range ( 6000 RPM to 8000 RPM) , the Malfunction Indicator Lamp (MIL) turns on and the DTC code is P0300 (Random/multiple Cylinder Misfire Detected). The motorcycle enter in a restriction mode and doesn´t allow us to increase RPM more than 4000RPM. We have already changed the A/F, MAP, ECT, CKP, rear wheel speed sensors and the PAIR CONTROL SOLENOID VALVE, ECM too.

We haven´t fixed it yet. We want to know if someone have presented this problem and solved it.

Best regards.View attachment 12733

View attachment 12733

2021 bike should still be under Warranty (2 years in Europe) so should be an issue for your dealer to resolve). I would suggest even if your somewhere with a shorted official warranty O would ask Honda in your country for some good will assistance on such a new bike.
NB in Europe you have some comeback against Honda up till years years after new for non fair wear and tear failures!

 

[trippy]

Hello everyone,

I have a CB650R model 2021 with a critical issue in a specific RPM range ( 6000 RPM to 8000 RPM) , the Malfunction Indicator Lamp (MIL) turns on and the DTC code is P0300 (Random/multiple Cylinder Misfire Detected). The motorcycle enter in a restriction mode and doesn´t allow us to increase RPM more than 4000RPM. We have already changed the A/F, MAP, ECT, CKP, rear wheel speed sensors and the PAIR CONTROL SOLENOID VALVE, ECM too.

We haven´t fixed it yet. We want to know if someone have presented this problem and solved it.

Best regards.View attachment 12733

View attachment 12733

I'd check:
O2 sensor
sparkplugs
fuel lines

 

[User23]

I'd check:
O2 sensor
sparkplugs
fuel lines

These components were replaced and the fault was not fixed.

 

[EZFLYER75]

These components were replaced and the fault was not fixed.

Maybe bad fuel guality?

 

[skeletor]

battery condition and connections are ok?

 

[User23]

battery condition and connections are ok?

yes, battery ok and connections too.

 

[Ive]

For misfires, I'd also check the ignition coil connections, most notably, those spade connectors on top coming from the ECU. While I never issues arising from them, those connectors on mine seemed looser than normal when I had to unplug them temporarily in order to reroute other added accessory wires.
After checking physical connections, check coil voltages and then your ignition system (Section 5 of the service manual, available on this site).

 

[Leonidas Pappas]

I just got the same issue. Got engine light on and they remapped the ECU to factory settings. Now i have to look out if anything else happens. What was the problem in your case eventually?

 

[Xaoc]

Same issue here... Local dealer just performed diag and cleared the light 😕. They said that all parts are operating normally and no need to replace anything. I'm expecting MIL light to come on again... It would be nice to hear/know if ECU reset solved the issue?!

 

[sp1d3r]

Man Honda really dropped the ball with these bikes. I thought the water pump oil leak was bad, can’t imagine what you guys are going through dealing with that issue. Can’t believe it’s not just a one off and multiple people are having the same issue with such new bikes. Seems like Honda reliability really is a myth. 🤷🏻

 

[miweber929]

Man Honda really dropped the ball with these bikes. I thought the water pump oil leak was bad, can’t imagine what you guys are going through dealing with that issue. Can’t believe it’s not just a one off and multiple people are having the same issue with such new bikes. Seems like Honda reliability really is a myth. 🤷🏻

ANY vehicle from ANY manufacture has issues. You may not think that's the truth but it is; while the water pump seems common it's mostly because people don't tell anyone when their bike is working fine and go looking for forums when it doesn't.

There is not a single instance of the waterpump leak being anything more than a nuisance on the forum. You can't say the same thing on many other bikes out there........

 

[Brian C.]

ANY vehicle from ANY manufacture has issues. You may not think that's the truth but it is; while the water pump seems common it's mostly because people don't tell anyone when their bike is working fine and go looking for forums when it doesn't.

There is not a single instance of the waterpump leak being anything more than a nuisance on the forum. You can't say the same thing on many other bikes out there........

I would agree, I've ben a bit paranoid about the water pump thing since I heard, but not even a drop so far so mine seems good. On the other hand it would be irritating if for every comment about the failed pump there were hundreds saying "mines ok".
Had mine coming up on 2 years and the only problems I have had, I caused!
I do think there needs to be a consideration of the way these forums "concentrate" issues where they can seem a high percentage of bikes get these problems, but in a wider context the failures are rare.

 

[Xaoc]

L @Leonidas Pappas did the ECU remap helped?