2001 gmc 2500hd 8.1l

start

#1

Check engine light is on. Code reads CAM Sensor , however i changed out the sensor myself and it still wont go away. My truck wont start on the first two-three times and it will back fire occasionally. Any suggestions on what to do next? thanks


#2

It’s possible the electrical connector itself is faulty. Try replacing the connector. It’s around $40 for the part.


#3

Anytime you replace that you need to do a Crankshaft Sensor Variation Relearn. This is according to the GMC forum.


#4

knfenimore…do you have a link available so i an read more about the variation relearn?


#5

http://my.cardone.com/techdocs/PT%2070-77-0003.pdf


#6

had a mechanic shop do the variation relearn and the code came back right after I left…


#7

Check the connector.


#8

the code has cleared…still backfires and wont start on first attempt…


#9

Did you use an AC Delco cam sensor?

Did you check the 5V reference and ground?

Did you check that the new cam sensor is actually producing a signal?


#10

Hi,

I know this postime is a few years old but I have a 2001 2500hd 8.1l with the exact same issues. Did you ever get this problem resolved? If so what was it? I’ve changed the cam sensor twice, first sensor was a BTW brand I think and it gave off low input code, second sensor was ac Delco brand which gave off high input code. I left the ac Delco in and changed the crank sensor and did a relearn and still setting a engine code, doesn’t want to start right away, backfires sometimes. Pigtail seems fine