Note On Intermittents

If PCM Code P012 is stored as a history code, start engine and allow it to idle. Manipulate circuits No. 430 and 453. An intermittent open will cause engine to stumble or stall when PCM loses distributor reference. If wiring and PCM connectors are okay, check ignition pick-up coil leads for intermittent open circuit.

Fig 1: PCM Code P012 Schematic - No Distributor (Tach) Signal

Courtesy of GENERAL MOTORS CORP.

Fig 2: PCM Code P012 Flow Chart - No Distributor (Tach) Signal

Courtesy of GENERAL MOTORS CORP.