GM Service Manual Online
For 1990-2009 cars only

Cranking Circuit

The cranking circuit consists of the battery, the starter motor, the ignition switch, and the related wiring. Only the starter motor will be covered here.

This vehicle with the 3.0L (L46) (VIN W) engine uses the PG260 F1 starter motor. This starter motor is not serviceable and is replaced as an assembly only.

Starter Motor

Notice: Never operate the starter motor for more than 30 seconds at a time. Allow it to cool at least two minutes before cranking again. Excessive cranking can cause overheating, which will cause serious damage to the starter motor.

When the ignition switch is turned to START, voltage is applied to the starter solenoid S terminal and the solenoid windings are energized. This causes the plunger to move the shift lever, which engages the pinion with the engine flywheel ring gear. The plunger also closes the solenoid contacts, applying battery voltage to the starter motor which cranks the engine.

When the engine starts, the pinion will over-run and spin at engine speed (rather than starter motor speed) to help prevent flywheel and starter motor damage. When the ignition switch is released (removing voltage from the solenoid) the plunger return spring disengages the pinion. To prevent excessive over-run, the ignition switch should be released as soon as the engine starts.