GM Service Manual Online
For 1990-2009 cars only

Third Gear Only

Checks

Cause

PCM and Transmission Wiring

    • Loose connector
    • Corroded connector
    • Defective PCM

Generator and Wiring

    • Loose connector
    • Corroded connector
    • Defective generator

Speed Sensor and Wiring

    • Loose connector
    • Corroded connector
    • Defective speed sensor

PCM and Wiring 1-2 and 2-3 Shift Solenoid Valves

    • Loose connector
    • Corroded connector
    • Defective quad driver