2007 S4RS engine and air temp sensor errors

Howie · September 11, 2026, 06:03:14 PM

That would be secondary.

axle167 · September 12, 2026, 01:48:15 PM

Quote from: Howie on September 11, 2026, 06:03:14 PMThat would be secondary.

Thanks Howie. Just to clarify.... Are you referring to the specs or the red and yellow readings or both?

Howie · September 13, 2026, 07:01:48 AM

No manual, no wireing diagram so I don't no color codes.

Howie · September 13, 2026, 07:12:37 AM

Oh, keep in mind windings can test good, but when running heat and vibration can open a winding. Same goes for electronics. It took some time on a dyno to find a bad coil and more time to find that the ecu was faulty too.

koko64 · September 17, 2026, 02:08:43 AM

Quote from: Howie on September 13, 2026, 07:12:37 AMOh, keep in mind windings can test good, but when running heat and vibration can open a winding. Same goes for electronics. It took some time on a dyno to find a bad coil and more time to find that the ecu was faulty too.

Very true.
Had a customer bike (highly modified FXRS) with failing spark. Had to book a dyno run to test it as it was an intermittent fault which turned out to be in the ignition module. Bloody thing wouldn't misbehave when we were watching even though we stress tested it. Pita.

axle167 · September 26, 2026, 01:37:41 PM

I ended up getting one new coil and tested it prior to install.

For reference, the new coil results are below:
the red wire to yellow wire test was 0.6 ohm
the black to spring inside the stick test was 14M ohm

ask tech to install the new one on the rear and reuse one of the less failed one in front as that is accessible and rode home. Bike ran better and rode home. CEL came on once and went away in a second on the ride home, it was a 15 KM ride

ordered a second coil and installed that one too.

couldn't even go one block without the CEL and parked the bike back home.

since the front coil was so accessible, I've pulled it and tested it.
the black to spring inside the stick test was OL.

switched the old coil and new coil a couple times to see any difference. Now the bike won't even idle

Also, it makes this noise with the bike on and not running. Anyone know what this noise is??

Howie · September 26, 2026, 02:54:04 PM

Maybe fuel pump?

koko64 · September 26, 2026, 10:21:35 PM

Put your ear to the tank to confirm. Thats quite loud. If it's the fuel pump that's not a good sound. Check the pump assembly and all its hoses and components.
You may have had concurrent issues for sure.

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2007 S4RS engine and air temp sensor errors