2013 Commander XT

[snuffleapagus]

Trying to help my father in law with his 2013 Can-Am Commander XT. When you turn the key, dash and lights go wild flashing, and it won't crank. We already swapped the battery and even the ECM. Still no luck. But weirdly, if we unplug the fuel pump or pull the fuse, the flashing stops, though it still won't crank and throws a comm error. Already checked all grounds and tried a new pump.

 

[DuneDrifter]

I had a similar problem with my friend's Commander not too long ago. It turned out that a faulty ground near the fuel pump harness was messing with the CAN signals. I'd definitely check the pump relay first, test the voltage at the pump plug, and give those wires a good look for any corrosion or damage to the pins. Oh, when you unplug the pump and cycle the key, does it still try to crank up, or does it just throw that communication error immediately?

 

[OffroadOutlaw]

Good call! I had a friend who had a similar issue with his '14 Commander. The dashboard went crazy, wouldn't crank, and there were random communication errors. We almost overlooked a corroded ground wire that was hidden behind the driver's seat. Once we cleaned it up and swapped out a dodgy relay, it started right up. By the way, does his still attempt to crank when you unplug the fuel pump, or does it just die immediately?

 

[StrangeOne]

Guys, he said he already checked ALL GROUNDS AND TRIED A NEW PUMP, so that's not it.

@snuffleapagus let me give you some real advice. You did replace the pump, but this could be a problem witth the wiring, specifically the harness. It doesn't have to be the ground, the harness itself may have gotten damaged. A multimeter can help you check continuity. You can also wigle it around and see if the weird things continue to happen or fully stop.

While you were replacing the pump, did you get a look at the connector? Also, the relay might also be causing similar problems.

 

[mmartyn_10]

Trying to help my father in law with his 2013 Can-Am Commander XT. When you turn the key, dash and lights go wild flashing, and it won't crank. We already swapped the battery and even the ECM. Still no luck. But weirdly, if we unplug the fuel pump or pull the fuse, the flashing stops, though it still won't crank and throws a comm error. Already checked all grounds and tried a new pump.

I'd also check the wiring harness like @StrangeOne suggested.
Thoroughly inspect the one leading to and from the fuel pump and its relay for any signs of chafing, corrosion or even a pinched wire.
Even a tiny short there can cause all sorts of bizarre electrical glitches.

 

[giowitzki90]

Guys, he said he already checked ALL GROUNDS AND TRIED A NEW PUMP, so that's not it.

@snuffleapagus let me give you some real advice. You did replace the pump, but this could be a problem witth the wiring, specifically the harness. It doesn't have to be the ground, the harness itself may have gotten damaged. A multimeter can help you check continuity. You can also wigle it around and see if the weird things continue to happen or fully stop.

While you were replacing the pump, did you get a look at the connector? Also, the relay might also be causing similar problems.

How do I safely check the harness with a multimeter without risking damage? And when you say "wiggle it," is that while the engine's running or just with the key on?