Buick Riviera Problem Report
Buick Riviera Crankshaft Position Sensor, Ignition/Powertrain Control Module May Fail
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.