Ignition coil 2: C25 error

Nefarioc

Registered
Hey guys, need some help. My bike is throwing C25 which I understand to be ignition coil 2. I tested the coil by pulling it with the bike running and it's not firing. The coil seems fine as I interchanged them and had the same effect. The light gray wire leading to the ignition coil plug didn't pick up any reading from my multimeter. I'm curious to know how I can fix this. Any help would be appreciated as I'm not that familiar with electrical work. Thanks!

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Inspect the harness all the way to the ECU, under the seat. You could have a chewed harness from mice.
Or a Bad ECU
Use a meter and test the wires pin to pin.
 
When testing for signal at the connector plug wires, probe the wire with your multimeter probe from the back side of the connector to eliminate the possibility of a bad (wire to) terminal connection causing excessive resistance.
 
Ok, thanks. I've checked the resistance of the dark gray wire to the terminal connection and found no resistance 0.00.
Does this mean my ECU is toast?
 
You checked continuity and the wire is good?
I think so...I'm not very proficient with a multimeter as this is my first go. I set it to 20K ohms to measure resistance and got 0.00 reading from ignition coil connector to the terminal connector that goes into ECU. I tested the light yellow wire on ignition coil 3 also and got the same reading. With number 3 being good, that tells me number 2 wire should be as well, right?
 
Ok, thanks. I've checked the resistance of the dark gray wire to the terminal connection and found no resistance 0.00.
Does this mean my ECU is toast?
Now you need to check for resistance (ohms scale on your multimeter)
from the wires in the (coil) connector plug all the way back to their corresponding pins in the harness connector plug that connects to the ECU
i.e. 1) All 4 coils grey wire go to a common O/W (orange with white trace) wire on the ECU connector plug
2) No2 coil black wire goes to the BLACK wire at the ECU connector plug

So check for continuity on these wires all the way from the coil wires on the harness to the ECU connector wires I have pointed out to check.
If there is no resistance, the ECU has a fault at the coil output pins.
 
Now you need to check for resistance (ohms scale on your multimeter)
from the wires in the (coil) connector plug all the way back to their corresponding pins in the harness connector plug that connects to the ECU
i.e. 1) All 4 coils grey wire go to a common O/W (orange with white trace) wire on the ECU connector plug
2) No2 coil black wire goes to the BLACK wire at the ECU connector plug

So check for continuity on these wires all the way from the coil wires on the harness to the ECU connector wires I have pointed out to check.
If there is no resistance, the ECU has a fault at the coil output pins.

Thanks, I'll do that. I think I misinterpreted you, though. What is the "terminal connection"? EDIT: nevermind...terminal connection is battery terminal, duh.

What I did was test the wires (dark gray #2 and light yellow #3) to the "harness connector that plugs to the ECU".
 
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If your multimeter doesn't tone a continuity test and it's not auto ranging, set it to the lowest (smallest) ohm setting.
 
Ok...I got a continuous beep when testing at this setting. Light gray to orange/white. I get the same beep when testing the dark gray wire as well as the yellow. Didn’t read any resistance when in ohms 20k.

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Good, that's continuity. 200 is the lowest resistance setting. You'd be looking for an ohm reading of less that one. At 20k, you're out of range
 
Ok...upon checking at 200 ohms.

Coil #2 (bad): lt. gray and dark gray wires read .3 at ecu connector.
Coil #3 (control):lt. gray and lt. yellow wires read .3 at ecu connector.
 
So with the wires showing the same resistance as the good ones (.3), the problem lies at the ECU, right?
 
[Quote; Thanks, I'll do that. I think I misinterpreted you, though. What is the "terminal connection"? EDIT: nevermind...terminal connection is battery terminal, duh.]

What I meant by 'terminal connection' was the female spade terminal to the male spade terminal IN the connector plug.
It'sn just so easy to be misinterpreted when trying to convey some technical sh$t in text, I hope you understand ;)
 
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