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rpmdiag, Tech and Instructor
Category: GMC
Satisfied Customers: 7892
Experience:  Since 1975
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1996 gmc savanna, 5.0, P0340, have tested cam sensor, am

Customer Question

1996 gmc savanna, 5.0, P0340, have tested cam sensor, am getting pulse, chased wiring from dist. to PCM...appears good, replaced CMP, and coil, has had recent T-up, has 12v power and good ground...scan shows cmp reads 0 at idle, jumps to -45 when throttled up....code appeared after i replaced CTS...
Submitted: 1 year ago.
Category: GMC
Expert:  rpmdiag replied 1 year ago.

Hi, welcome to Just Answer. I’m Ron and I’ll be helping you
Before we get started though, Please understand that I don't know
your skill level or tools you have to assist us. Also understand that
I can't see, smell, hear, or touch the vehicle either, so patience is
appreciated. JA is a great Q/A site, but it does NOT replace a
repair shop.
My goal is to make you happy and get a great rating in return for
my time. Sometimes I have to give you bad news that I know you
didn’t want to hear, so please don’t shoot the messenger.

Check CRANK and CAM sensors with a scope to be sure they look right. See attachment I sent to you.

Thanks, Ron

Customer: replied 1 year ago.
i am a retired mechanic with 30= years exp, am fairly well knowledgeable and have most tools i not have a scope....cmp shows good using vom....have good 12v and ground...wiring appears good from cmp to pcm
Expert:  rpmdiag replied 1 year ago.

A scope is needed for this, there are no shortcuts. We can guess at it all day and spend needless money by replacing a bunch of good parts. I want to help you, and we need to see what it's doing.

Thanks again, and please don't forget to rate me and keep this link in case you need me again later on.


Customer: replied 1 year ago.
i dont agree that a scope is nessesary, did you not read my reply? i tested with a volt meter and did get a live reading....