Dead ECM? C41

[amirpc]

Hey guys,

I'm getting a C41 from my ECM. I've read all of the other C41 posts I can find and they are mostly centered around bad fuses, bad relays, bad pumps or bad connections.

Here's what I'm seeing:

1. No prime when I turn the key
2. If I jump the fuel pump (Y/R to R/Bl) at the relay harness, fuel pump comes on and I can start the bike
3. If I jump Y/B to ground directly, I can hear the relay clicking and the fuel pump comes on,
4. Tested the Relay itself using procedure in the service manual, and when I put 12V across it I can literally hear it clicking
5. No clicking at relay when I have installed and try to start bike
6. All fuses are good as far as I can tell

I'm looking at this diagram and I can confirm that:

Control side:
- O/W shows 12V when key on and ignition on
- Y/B seems to show 12v, but drops to 10v when I push the start button. I believe this is supposed to ground when the start button is pushed? Am I wrong?

FP side:
- R/BI shows 12v at all times (key on or off)
- Y/R shows nothing ever, which confirms no power to fuel pump

Also tested continuity between pin 39 and Y/B plug for fuel pump relay, so it's not a bad connection

To me this says that the FP relay line on the ECM is fried. Meaning Pin 39 isn't going low when it's supposed to.

What am I getting wrong here?

 

[Kiwi Rider]

Have you checked the tip-over switch for correct operation? It disconnects bat voltage to the fuel pump relay. I think.

 

[amirpc]

Have you checked the tip-over switch for correct operation? It disconnects bat voltage to the fuel pump relay. I think.

I did originally get a code for the TO sensor but pulled it and tested the voltage coming from it at various orientations. It seemed right. Then I plugged it back in and then the code mysteriously went away.

 

[amirpc]

I don't think it's the tip over sensor, if I ground out the control pin for the fuel pressure relay that is coming out of the ECM, the bike starts right up.

That seems like ECM isn't grounding pin 39 the way it should, like the internal fuel pressure relay transistor is fried.

 

[amirpc]

Here's a video of me testing it. You can see that the ECU pin 39 isn't grounding out the yellow/black wire to the fuel pump relay, but when I jump it to ground everything works.

Dead ECU, yeah?

 

[ottafish]

More as info more than anything...
The ECU from my '14 bike had a similar issue, but different system.
My cooling fans would never turn on. Went through everything to sort the problem out.
Turned out the ECU was faulty and the fan control form the ECU never dropped to ground to kick the fans on. (sound familiar?)
Swapped out a ECU from a wreckers, and fans came alive, worked first time. Hasn't missed a beat since.
So, yep, it wouldn't surprise me if it's the ecu gone bad

 

[michael parris heuberger]

More as info more than anything...
The ECU from my '14 bike had a similar issue, but different system.
My cooling fans would never turn on. Went through everything to sort the problem out.
Turned out the ECU was faulty and the fan control form the ECU never dropped to ground to kick the fans on. (sound familiar?)
I have had a few ECUs, go bad, started bike shut it off and would not restart it burned out a printed circuit board.