2006 Buick Rendezvous, 171000 miles, 3.5 motor, 2 wheel drive. Randomly will not start. It cranks over just fine but the motor does not start. Most of the time the motor starts and it runs great. There are no lights on the dash even when it fails to start. There are no error codes in the computer either. What I have replaced so far:Checked fuel pump fuse, replaced fuel pump relay, replaced crank sensor, and just replaced fuel pump. Buick dealership tech mentioned Body Control Module and ignition switch next. Could be some type of problem with the security system. I have posted in the last couple of weeks, just giving an update and to see if any one has any ideals what to do next! Thank You!!!
The first thing you always need to determine in a no start situation is whether it is a lack of fuel pressure or a lack of spark. You can get a spark tester for as little as $5 and a fuel pressure gauge for as little as $20. Once you determine which is causing the problem you can take it from there. Those are the basic first steps.