2009 Express 2500 6.0L V8 - 95,000 miles
What would cause engine RPM to drop when shifting trans into reverse? At idle engine is at 600 RPM, when I shift into reverse the idle drops to 250-300 RPM. The engine actually stalled on one occasion. Where would you start to diagnose this condition? MIL is off. No DTCs from my hand-held scan tool.

 

I have the same issue with my Silverado 3/4 ton new trans replaced almost everything under the sun did
you ever figure it out?

 

Something similar when shifting to Drive from Neutral?

 

When u shift from drive to reverse when warm my rpm drops and seem like truck wants to stall

 

Okay, try N to D, same?

Think OP was referring to Park->R.

 

 

Check tranny fluid. If just changed, make sure the right fluid was used and is at correct level.

I'm assuming engine tune, etc. is fine, otherwise drive would have the same problem. Possible the tranny is not spinning freely as it should for the first few seconds after shift to reverse, maybe heavy fluid or gunk.

 

Fresh fluid just rebuilt in March fluids good ,drives me nuts had tranny scanned and everything internally works good , hoping it sorts itself out.