How to test crank sensor

[LanduytG]

Can anyone tell me how to test the crank sensor? In the GM shop manual you use a scope and check to see if it is putting out 60HZ at 900 rpm. Well I have a scope but the son in law has it and I won't be able to get it till next week. Any thoughts on this? I am sure its bad but I want to verify it before buying another one. All wiring back to the PCM checks good so nop wire problems. Could be PCM problem but I still need the scope.

Greg

[larsajoh]

I don't know if this helps, but when mine quit the engine started to sound very "hard", allmost as when it is cold.

It turned on the SES light, and the dealer said it showd a code. Sorry, don't know witch code....

[gmctd]

DVM with Frequency input could verify rpm count, but scope is only way to verify 0 - 5v waveshape and amplitude.

[LanduytG]

Lars
Yes it took several turns before starting and then really idled hard.

I just replaced the sensor and all is well. I did not know it was only $38.

Did you get your oil lines?

Thanks
Greg

[ucdavis]

Greg-
Was that $38 @ a dealership?
I'm getting ready to head to Mexico & would carry that spare is that's all it costs.
Thanks.

[LanduytG]

ucdavis
That was from the local parts store, dealer wanted $64.

Greg

[ucdavis]

Naturally. You don't happen to have the part# do you?
Thanks