Hello Guys,

Back in August of 2016 I bought a 2001 Lesabre Custom. Car was owned by an older woman who lived in Manhattan. Dealer maintained. She kept it in a parking garage most of its life. Bought the car. Changed the transmission fluid ( dropped the pan and changed gasket), put brakes and tires on. No problems.

Fast forward to early November, early in the morning when I went to start the car it would not start up (only in the cold). When I go to turn the key, all the electronics (radio, lights, etc) turn on, but when I go to turn the car over. Nothing. Not even cranking. Not even a click . Nothing. When I hold it more than a few secs the service engine soon light gets illuminated until i stop ( probably holding the key too long).

Fsat forward to now. Has been to dealer more than five times. Repair shop more than 5 times. Changed a starter, crankshaft position sensor and more recently for $700 ( very costly) a dimm module and they reprogrammed the car. Car was good, fired right up for about 3 weeks. Now In February I was stranded at my job, (AGAIN) and 3 weeks after this $700 repair (They werent sure it would fix it, but it did for at least a few weeks) I'm back with the SAME problem. Tried the second set. Starter is good. Nothing. NO crank, no nothing.

I'm so frustrated because I'm a student in his last year of college 25 years old and work two jobs. One of my jobs is 25 miles away. AS such, I just bought a 1998 Grand Prix coupe with 72K (Just to hold me over a year or two, in the event this car can't get fixed.)

The car is back at the same shop that replaced the DIMM module. They will look at it tomorrow. It'* a shame, because the car only has 95,000 and interior and everything else mechnically is PERFECT. It will break my heart to have to junk this car. But I'm reaching the point of no return. So far I've invested over $1,000 in a car I only paid $2500 for. Any ideas whats wrong here? Because I'm sure the shop will tell me I need to replace another expense computer. Faulty wiring? Bad Ignition Switch? IGnition control module perhaps?

I've already replaced the Starter, Battery, Crankshaft Position Sensor and now DIMM module. WHen I REplaced the DIMM Module it was fine for almost as month. Now same stuff all over again. Any ideas? I really would hate to get rid of this car. Again its a no crank, no start issue. All lights illimuate, all lights on, but when I go to Start it...NOTHING. Not even a crank. Not even an attempt to start it. Please help me. I don't want to junk this car. I want to keep it.

I won't claim to be a professional, but I am fascinated by the electronics and have 'hacked' this serial bus system to install the stereo and keyless entry from the '05 LeSabre into my car.

My first question is, does the anti-theft system prevent the starter from engaging? I don't believe it does, but I hope an expert can tell us for sure.

I personally think they are probably just throwing parts at it. As the DIM is the power mode master of the serial bus system, and everything came to life except engagement of the starter, this seems unlikely. The DIM is easy to install and marries on first power up, so this is an easy swap. You can draw your own conclusion.

My first guess for an intermittent might be the relay in the under hood fuse block. A cheap and easy swap for an intermittent problem, if this hasn't been done. I've included the schematic of the starter circuit.

I might add that I have run across a number of beautiful GM serial bus cars that have been junked that are dead when I power them up. Some failure on the bus killing the entire car. I think people give up on them.

I tend to agree on this...sounds like someone is shotgunning parts instead of doing some diagnostics here......

When you turn the key to "on"(not the crank position), look at the SECURITY LIGHT in the cluster....does it go out after 3 seconds or does it stay on? If it stays on, that is your problem....