how to tell if M112 crank position sensor is bad

[5banger]

My friend's C240 was experiencing the classic stalling when slowing for a turn, etc. and I pulled the CPS. The tip was scraped off a bit--maybe the tolerances weren't right? But, I don't think it was deep enough to cause a fault. The new Hella version I put in measured 600 ohms, while the factory original was about 1200 ohms. With a heat gun, I couldn't get the old one to go open-circuit, but it did go up to about 2000 ohms -- how resistive is too resistive for for this sensor? Any other ideas to tell if it was bad? If I were to hook it to a scope, what type/strength magnet would I need to test with? What amplitude pulse is good enough for the factory computer to register it successfully? i.e. how would (if) the dealer test these? Thanks for the tips! Andrew.