[KChappers]

Hi All,

I have searched multiple treads on this and different sites and cannot find my exact problem, here is what is happening.

When the key is turned I don't hear the fuel pump prime but all other lights work and the speedo does its normal sweep.
In neutral, stand up, kill switch to run, clutch in - cranks but wont start.
Dash comes up with "CHEC" and red light is on. (from research this tells me that the ECM has no signal/power?)
Tried putting it in dealer mode but stays on "CHEC" and wont change to show a code

-Battery sitting around 12v with ignition on, 12.6v ignition off. (possibly a little low)
-Checked the fuel pump with separate 12v and runs fine
-Checked the fuel pump relay and all is good
-Checked all fuses under the seat are ok with a multi-meter

Things I still need to check-
Kill switch is working
Turn Over sensor is working
Stand switch is working
Swap with a friends ECU/ECM

anything else I can check???

Thanks in advance.

 

[rv6john]

Welcome to the forum.

Yes, CHEC means the ECM is not sending data to the cluster. Either the ECM does not have power or it is bad.

Since you swapped ECMs with the same result (that is a good sigh) then that leaves a power issue.

You did not mentioned that you had checked the fuses. The ECM gets power from both the fuel and ignition fuse.

Is this something that just started happening?

 

[KChappers]

Welcome to the forum.

Yes, CHEC means the ECM is not sending data to the cluster. Either the ECM does not have power or it is bad.

Since you swapped ECMs with the same result (that is a good sigh) then that leaves a power issue.

You did not mentioned that you had checked the fuses. The ECM gets power from both the fuel and ignition fuse.

Is this something that just started happening?

I haven't had a chance to swap the ECM yet, but it is on my list to do once my friend is available to help, I did check the fuses (ran a multi-meter over the top but without removing them, so will take them both out to check again)

The bike wasn't used for about two years, although it does have fresh fuel in it and injector cleaner, it did start as I took it to the MOT station to be tested (in the UK we have to have the vehicle tested once a year) it was only after filling the fuel tank and putting the injector cleaner in that it has stopped.

 

[XPOH]

Things I still need to check-
Kill switch is working

I guess it is most significant reason in this situation.

Try to do following. Turn on neutral, ignition on, while pushing the kill switch on run position by your finger move you finger left and right. Watch for CHEC disappearance on the dashboard. If it disappeared, then you should to disassemble the kill switch and provide strong contact in it.

 

[KChappers]

So, findings after having a couple of hours to do some tests:
Kill switch is fine - tested continuity and all good at the switch
Ignition barrel - tested for 100ohm across O and O/W and all good (hoping that I tested it correctly)

Strange thing I did notice was that the battery just sitting is at 12.4v but once the ignition is on it goes down to just under 11v I assume due to lights ect running, didn't get a chance to test while it was cranking as I need another set of hands.

could it be as simple as the battery isn't charged enough? what voltage should I see with ignition on? I assumes that as the bike was cranking as normal the battery was fine?

 

[rv6john]

This could be your issue. A good battery is about 12.8 volts resting and only goes down a few tenths with ignition on.

The key is that it has to stay above 10.5 volts while the starter is cranking to keep the ECM happy. My guess is that it is going to be well below that.

 

[KChappers]

thanks for the quick response, would this also cause the fuel pump not to prime as well then?

 

[rv6john]

thanks for the quick response, would this also cause the fuel pump not to prime as well then?

The fuel pump is controlled by the ECM. If it's not happy then no spark or fuel. It gets unhappy below 9-10 volts.

 

[Chuckster]

If it'll turn the engine with the starter, it's got enough juice to properly power up the ECM.

On the big connector of the ECM, look for the O/W wire. This is the main power for the ECM. There are some diagnostic service plugs too. Probably best to check at that point for the voltage. Key and stop switch on of course. If that has power, then it's a bad ground, or bad ECM. Also guessing the STVA doesn't do anything, so I wouldn't bother looking for connection issue between the ECM and cluster yet.

Look at 9-19 of the manual. It's a nice diagram. The power wire in is the O/W wire.

 

[KChappers]

Well I cant get it in dealer mode either so i an guessing the ECU doesn't have (enough) power or is FUBAR?

 

[Chuckster]

Two of the possible options, yes. You have to test to determine which, if either, problem you have.

 

[XPOH]

Strange thing I did notice was that the battery just sitting is at 12.4v but once the ignition is on it goes down to just under 11v I assume due to lights ect running, didn't get a chance to test while

I had same issue on my 50cc moto scooter. The battery was voltage about 14,7-14.8 in no load condition and 6-8v when turn on starter or headlight. I droven my scooter to battery shop and the seller tested my battery with battery load gauge, and it was dead. I bough new battery and and issue was disappeared.

 

[KChappers]

Tried a brand new battery last night with no luck, so that is the battery ruled out.

 

[KChappers]

found a wiring diagram as well for reference

 

[XPOH]

Connect any ampermetre with 10-15A range between positive battery terminal and red wire leading to it. Turn on ignition and measure the value of current. Then turn off ignition and measure again.
Post this values here please.

 

[KChappers]

If it'll turn the engine with the starter, it's got enough juice to properly power up the ECM.

On the big connector of the ECM, look for the O/W wire. This is the main power for the ECM. There are some diagnostic service plugs too. Probably best to check at that point for the voltage. Key and stop switch on of course. If that has power, then it's a bad ground, or bad ECM. Also guessing the STVA doesn't do anything, so I wouldn't bother looking for connection issue between the ECM and cluster yet.

Look at 9-19 of the manual. It's a nice diagram. The power wire in is the O/W wire.

There is no O/W going into the ECU - (mine is a UK bike, dont know if US is different?)

looking at the wiring diagram I posted looks like the O/W changes to O/G somewhere so I will test that for 12v I guess?

 

[KChappers]

Connect any ampermetre with 10-15A range between positive battery terminal and red wire leading to it. Turn on ignition and measure the value of current. Then turn off ignition and measure again.
Post this values here please.

I can try and test this but surely this will just tell me that the battery (which is brand new) has the correct ampage?

 

[Chuckster]

You're correct about the E02 wiring. But it's strange because the hot line that goes to the coils, then just goes to what looks like a ground bundle. Might be an error in mine.

 

[KChappers]

now wondering if it is an immobiliser issue as it is a UK bike. But I have no idea where it is or how to test for this lol.

 

[XPOH]

I can try and test this but surely this will just tell me that the battery (which is brand new) has the correct ampage?

No, this simplest test will tell you about correct or incorrect connection and shortcut existence in main supply circuit. Easy and effectively.