Hello all,

I'm a young kid, owning my first truck and im having a problem. I'm not mechanically sound in cars and trucks yet, but I soon will be.

The problem I'm having is that when I would park at my friends house in a certain spot, then get back into the truck and start it, the engine would shut down as soon as I put it in reverse. Now I was thinking and so was my friend (who is more mechanically sound then I am) said that it was maybe the fuel flooding the system. It was a fluke thing and didn't happen for about a month. Then I went back to my friends house and in the same spot as I parked the first time, the truck did the exact same thing. Start it up, put it in reverse, engine cuts off. All electrical stays on inside the cab power locks, windows lights radio, all that stayed on, but the engine cut off.

Finally I went bowling just yesterday out to Hartland, I left and got all the way there with no problems starting, stopping, driving....nothing. After I get done bowling and heading home again with my friend (the same friend that I parked my truck at his house) he is in front of me and were both going about 70 on the freeway, the engine again just shuts down while im driving. I coast to the side of the road and turn my hazards on. Thank God my friend saw me and stopped and came back to help. I tried starting her up before he got back to me and it would crank, but not turn over. He got back to me and we waited about 10 mins while he called a buddy of his. I got back in and cranked it.....and it started, and ran fine all the way home. I already took this problem of "engine cutting off" to my mechanic and he has absolutely no Idea what it could be.

Mind you that the time between the first encounter with this problem and the second was about a month.

The second encounter to the third was 5 days. Now I don't really trust to drive my truck knowing it could shut off again on me at any point while driving. I'm just looking for a cause or to see if any of you have seen or experienced this problem before. Thanks for reading and hope I can find some answers.

crank position sensor is normally the failure when engine is hot then when cool it works. that and the maf are the only things that will just cut off the engine normally. but the maf you can test, if it wont start and you can unplug it. if it starts after you unplug the maf its bad

Yeah I had a problem also with the Crank sensor and I did replace that a year ago. It did the same thing a year ago, my mother drove the truck and it died on her while at a stop light.

I told my mechanic about the maf (thanks to my friend telling me about the maf) but he kept saying the "map" I dont know if that is the same thing, but I did tell him to check that and also maybe even the Neutral Safety switch.

The MAP is the manifold air pressure sensor. With it just dying I'm inclined to say it still a crank sensor issue. The best thing to do is get a scanner or at least a code reader and see if the PCM has stored any codes. Sometimes a faulty crank sensor will set a history code and give you a direction to go.

Alright thanks guys I appreciate it. My mechanic did say he would check out the MAP but I don't know if he will check the crank sensor so next time I talk to him i will mention it. Is this a common problem with GM? or GMC

i understand that this truck is a 2005 and it has 146 thousand miles, I know there is going to be problems becuase I think I stuck like 3-4 grand in the last year ive had it. I'm just trying to build up some knowledge that will help me for future problems.

Thanks again guys

I have not seen a bad crank shaft position sensor set a code, but I do agree it is the most likely candidate for what your problem is.

I have on the LS truck engines quite a few times but I've never seen it on the v-6 engines

I have a whole fleetest of delivery trucks with the 4.8 and 6.0LS engines. I'm sure I see a higher failure rate of the crank sensor because of the 200+ engine start-stops they do a day but yes I have replaced many crank sensor on this engine.

Mine is a V-8 and like I said I did replace it before, I believe it was original so obviously after a 146 thousand miles it should be replaced. Can these go bad or fault within a year? is that normal?

I would check the plug at the sensor. It can have a bad connection or a broken wire that will cause this issue if you have replaced the sensor once.