GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The PG starter motors are non-repairable. They have pole pieces that are arranged around the armature. Both solenoid windings are energized. The pull-in winding circuit is completed to the ground through the starter motor. The windings work together magnetically to pull and hold in the plunger. The plunger moves the shift lever. This action causes the starter drive assembly to rotate on the armature shaft spline as it engages with the flywheel ring gear on the engine. Moving at the same time, the plunger also closes the solenoid switch contacts in the starter solenoid. Full battery voltage is applied directly to the starter motor and it cranks the engine.

Reference Information

Schematic Reference

Starting and Charging Schematics

Description and Operation

Starting System Description and Operation

Circuit/System Verification

Start the engine. Listen to the starter noise while the engine is cranking. The noise should be comparable to a similar vehicle.

Circuit/System Testing

  1. Remove the flywheel inspection cover.
  2. Inspect the flywheel for the following:
  3. • Loose flywheel bolts
    • Chipped gear teeth
    • Missing gear teeth
    • Bent flywheel
    • Debris in the bell housing
    If not within specifications, secure the flywheel bolts or replace the flywheel.
  4. If all inspections were within specification, replace the starter motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Fastener Tightening Specifications for the 4.2L (LL8) engine
    •  Fastener Tightening Specifications for the 5.3L (LH6) or 6.0L (LS2) engine
    •  Engine Flywheel Replacement for the 4.2L (LL8) engine
    •  Engine Flywheel Replacement for the 5.3L (LH6) or 6.0L (LS2) engine
    •  Starter Motor Replacement