No spark on real cylinder. Coils/wiring check good. What next?

[shabazz18]

After sorting through a bunch of other stuff I found my problem. No fire on the rear cylinder. Wiring and coils appear to be good. I've checked multiple coils and they work on the front but not the rear. Could the ecm be bad?

[Cooter]

Do you have a signal to the rear coil?

[shabazz18]

Do you have a signal to the rear coil?

Do I look for voltage or ground on the signal wire?

[Cooter]

Key on, you should have battery voltage at the could plug. Cranking you should have a pulsing signal on the ground side.

Or with voltage to the plug, you can tap the jumper on the ground wire to ground and should get a spark.

[shabazz18]

in all likelihood not. i'm assuming here that your coil replacement job was with known GOOD coils.
i'm assuming here that you checked for any stored or active fault codes via either ecm access or jumper wire method.
i'm assuming here that you have a new plug in the rear cylinder and the wire to that plug is a known good piece.
if all the above is true and accurate then next step is go remove the front pulley cover. held on by 3 torx screws.
remove the cover and carefully inspect all the wiring looms and connectors behind same. check the large shielded wire that goes from the harness to the cam cover area. it is the wiring loom for you CPS assembly. check for any nicks, pinches, or rub thrus. report back.


Key on, you should have battery voltage at the could plug. Cranking you should have a pulsing signal on the ground side.

Or with voltage to the plug, you can tap the jumper on the ground wire to ground and should get a spark.

Ok, so yes, coils were verified working by installing on the front cylinder. The original rear is now on the front and vice versa. Plugs are new. No codes other than IAC while running. Coil wiring has a constant 12v and middle ground. The signal wire has a pretty steady .5v with key on and about .6 while running. I'm pretty sure this is wrong. I've tested while running and while off firing the rear coil with ECMDroid. This is whats behind the pulley cover. Not really sure what the terminated plug is for. Wires look good.

http://imgur.com/WdEhAem

http://imgur.com/Ca3rhCn

[Cooter]

For a 2 wire coil..."Key on, you should have battery voltage at the could plug. Cranking you should have a pulsing signal on the ground side."
For a 3 wire coil... the plug will have a Battery voltage on one side, ground on the other side, and a signal wire in the middle that will pulse while cranking.

Either way, you can't check for a "pulse while cranking" without the bike cranking.

You are checking the ECM output and wiring with this test, not the coil.

The first pic is the wiring for the kickstand safety switch that you do not have on your bike.
The second pic is not a terminated wire, it is your speed sensor and unrelated to your problem.

"I've tested while running and while off firing the rear coil with ECMDroid" The rear coil fires with ECMDroid, but not while running?!? Your confusing post.... is confusing.

[shabazz18]

For a 2 wire coil..."Key on, you should have battery voltage at the could plug. Cranking you should have a pulsing signal on the ground side."
For a 3 wire coil... the plug will have a Battery voltage on one side, ground on the other side, and a signal wire in the middle that will pulse while cranking.

Either way, you can't check for a "pulse while cranking" without the bike cranking.

You are checking the ECM output and wiring with this test, not the coil.

The first pic is the wiring for the kickstand safety switch that you do not have on your bike.
The second pic is not a terminated wire, it is your speed sensor and unrelated to your problem.

"I've tested while running and while off firing the rear coil with ECMDroid" The rear coil fires with ECMDroid, but not while running?!? Your confusing post.... is confusing.

No, the coil never fires, even when telling it to fire with ecm droid. Is that not the crank sensor pictured? I thought the speed sensor was on the other side.

Coil is 3 wire, and I've tested while running on the front cylinder, so it should definitely be firing, or at least trying to. Battery voltage is present on the grey wire. The middle black wire is always ground and the blue/orange has @.5v at all times running or not. No real change. Ive verified that the wiring is good from the blue/orange at the coil to the ECM

[shabazz18]

So, running or not, the known good coil will not fire, nor is any signal being pushed telling it to, even when sent manually. This is why I suspect the ECM is bad.

[Cooter]

IF:
The coil is known good
The wiring has been continuity tested between the ECM pin and the coil pin
The supply voltage to the rear coil is good
The ground to the coil, including the ground to the chassis from the coil body has been continuity tested.

Then, As rare as a faulty ECM is... I would be comfortable changing the ECM.

Where are you? I might have a DDFI-3 ECM for you.

Edit: Yes that's the crank sensor, pic was too close for me to see. The crank sensor tells the ECM when the motor is at TDC, the ECM tells the coils when to fire (individually). Since the front coil works, the CPS is not the problem.

[shabazz18]

IF:
The coil is known good
The wiring has been continuity tested between the ECM pin and the coil pin
The supply voltage to the rear coil is good
The ground to the coil, including the ground to the chassis from the coil body has been continuity tested.

Then, As rare as a faulty ECM is... I would be comfortable changing the ECM.

Where are you? I might have a DDFI-3 ECM for you.

Edit: Yes that's the crank sensor, pic was too close for me to see. The crank sensor tells the ECM when the motor is at TDC, the ECM tells the coils when to fire (individually). Since the front coil works, the CPS is not the problem.

Checked ground to battery and subframe, is there another location I should check? Everything else on your list checks good. It has compression as well, but my gauge is trash so I dont have an accurate number, but I'm pretty sure its over the required 120psi. I'm gonna get a new one this week.

[shabazz18]

also, I'm in Arlington TX

[shabazz18]

Edit: Duplicate

[Cooter]

"
Then, As rare as a faulty ECM is... I would be comfortable changing the ECM.
"

[shabazz18]

"
Then, As rare as a faulty ECM is... I would be comfortable changing the ECM.
"

What would you need for the one you have?

[shabazz18]

Changed the ECM. I have Spark!!! Flashed the factory tune. Now just gotta put it back together and actually ride it for the first time. Thanks for your input.