2008 YZ450F TPS Sweep Inverted

2 replies to this topic
  • BMcEL

Posted January 08, 2015 - 03:07 PM


I've been having an intermittent misfire at low load and narrowed it down to the throttle position sensor. Misfire is completely resolved when the TPS is disconnected. This is apparently a common issue on these bikes. My problem is, when I put my meter on the TPS, the sensor coil is in spec but the sensor coil variable resistance (or sweep) is inverted. The high and low values are in spec, just inverted. Resistance decreases as you open the throttle instead of increasing like it should. Has anyone ever seen this? My only guess at this point is that the original owner replaced the TPS with the wrong one.


I'm leaving the TPS disconnected for now but I would like to get the 3D ignition mapping back at some point.

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  • grayracer513

Posted January 08, 2015 - 03:23 PM


What the resistance does depends on which two leads you check.  checking yellow to black it goes up as you open the throttle. Yellow to blue, it goes the other way.

  • BMcEL

Posted January 08, 2015 - 04:34 PM


I swear the leads were on yellow & black. I didn't have that many beers. Or maybe I did.

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