derbybug350 Posted April 13, 2008 Report Share Posted April 13, 2008 Hey guys, Im new to this site and have spent the last 4 hours reading the very interesting questions and replies to the various topics. I have yet to find an answer to my problem though. My caddy has an intermittent no start problem that is driving me nuts. It didnt start AGAIN last night after work and the driver info panel stated " service fuel system". This has happened several times. The engine will turn over for ever but not fire. I am a heavy truck/bus diesel tech and am very skilled in the mechanical field but cant find any info on this problem. I am beginning to wonder if the ignition cylinder is starting to go bad and the sensor in the switch occasionally doesnt read the pellet on my factory keys correctly, therefore shutting off the fuel pump relay. I cleaned the pellets on the keys today to no avail. Last week the car wouldnt even turn over and the driver info panel stated " security error wait 5 mins" or something to that effect. I waited the 5 mins and the car started and ran fine. I pulled the codes today and I got the P0231 code for the low voltage on the fuel pump circuit. I hooked up my Snap-on scanner and it said that the fuel pump relay was inactive(OFF). I checked the fuel pump fuse and its fine. The relay is new and operational. What is malfunctioning to shut down the fuel pump relay? Would it be the BCM(body control module)? I cant find any info on how this security system works and cant test each module individually with my scanner. I went to the library for a couple hours researching ALLDATA.com and found the diagnostic chart for code P0231. When i got back to my car to start the diagnostics on that, the car started right up(like there was nothing wrong) maybe I hold a grudge longer than my caddy does but this is starting to piss me off. I want to get to the bottom of this before I get stranded some where where I cant walk home in the 38 degree windy rain that I did last night (on friday of all days too. Sorry this is so long but I want to be as complete and accurate as I can. ANY info or suggestions would be greatly appreciated. Thank you and I will be helping and replying to others on this site as I find it very interesting and helpful. Thanks, John Link to comment Share on other sites More sharing options...
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