Replace PCM 1999 Saturn SC Series

1999 Saturn SChad to replace pcm unit. it says what causes that is voltage overload-often due to short in solenoid or actuator circuit. what does that mean?


Voltage overload is when a larger amount of voltage is seen compared to what it is normally capable of seeing.

A short is when a positive connects with a negative.

A solenoid or actuator is an electrical device that move when voltage is applied.

So what is being said is something shorted out in a solenoid or actuator circuit(the sytem in which it operates). The short caused a voltage spike(positive or negative) to the PCM – Powertrain Control Module (engine computer). And the end result was the computer was damaged.

Replace PCM

Removal Procedure

Important Record present radio stations and clock time. Disconnect negative battery cable.


  • Remove I/P upper trim panel outer cover fillers by carefully lifting up at clip locations, starting at the rear above end cap.
  • Remove I/P bolt caps by carefully prying with a small flat head screwdriver.
  • Take out I/P upper trim panel screws.
  • Lift I/P upper trim panel at clip locations on rear edge to disengage clips.
  • Pull I/P upper trim panel rearward out of clips at bottom of windshield.
  • Important Be careful when removing or replacing I/P upper trim panel, not to damage VIN plate.
  • Remove I/P upper trim panel.
  • Important Be careful when removing or replacing I/P upper trim panel, not to damage upper trim panel seal.
  • Remove I/P upper trim pad sound insulator.
  • Disconnect PCM electrical connector from under instrument panel.
  • Important Do not pull on the connectors or wires to remove the PCM. This could back out a terminal and cause an intermittent connection.
  • Loosen PCM attachment out at cross car beam and lift PCM upward (towards windshield) to disengage PCM from ABS/PCM bracket.