The crankshaft position sensor, ignition module, and/or powertrain control module (PCM) may fail resulting in illumination of the Check Engine Light with ignition system related fault codes stored in the PCM. Patience is necessary when dealing with this specific situation as normal diagnostic procedures are not effective. In many cases, the best option is to replace parts, one at a time until the fault is corrected.Google+
Car Problem Reports
Pontiac Grand Prix Crankshaft Position Sensor, Ignition/Powertrain Control Module May Fail
Pontiac Grand Prix Problem
Exhaust & Emissions Affected: 3.8L V6
Visitor, 2000 Pontiac Grand Prix, 260,000 mi
something is shorting out my battery and prventing my car not to start and im not sure what the exact problem is. I had a mechanic to look at it and it printed of a p400 code?