Possible causes

– Faulty Powertrain Control Module (PCM)
– Powertrain Control Module (PCM) harness is open or shorted
– Powertrain Control Module (PCM) cicuit poor electricl connection
– Low battery voltage

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P0601 BUICK Description

The Powertrain Control Module (PCM) EEPROM contains data which is essential to running the engine and transmission. The PCM continuously tests the integrity of this data.