crank position sensor
Thread Starter
Drifting
Joined: Oct 2013
Posts: 1,577
Likes: 121
crank position sensor
About 2 years ago i changed the starter on my LS7 and changed the crank position sensor while i was doing it. I have about a thousand miles after the sensor change with no known problems. After reading threads on here it seems i needed to do a relearn on the sensor. With my code reader i was not showing any misfires but i still decided to do the relearn. The reader said to rev the motor wide open to redline and let off when hitting redline or fuel shut off. I was not comfortable reving to redline without a load so i went only to about 5k Scanner said i was succesfull but was i? There were still no misfires showing and when i started to go through the procedure again the scanner said relearn was already done. So question is. Was the relearn successful or could i get misfires above 5k up to redline?
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,595
Likes: 4,055
From: Cape Coral, Florida
If your scan tool said you were successful you’re done !!…even if you did not do the relearn you may not see misfires and these would be ones that will count up on a scan tool but will not be felt…the ECM sees the crankshaft slow down by interpreting the crankshaft position sensor signals rising or falling edge and can determine this by the width of the signal which is a digital square wave.
Last edited by C5 Diag; May 11, 2025 at 09:44 AM.
