GM Service Manual Online
For 1990-2009 cars only

Harsh Shifts

Checks

Causes

Throttle Position Sensor

Open or shorted circuit

Vehicle Speed Sensor (36) or Input Speed Sensor (250)

Open or shorted circuit

Trans Fluid Temperature Sensor (Part of 66)

Open or shorted circuit

Engine Coolant Temperature Sensor

Open or shorted circuit

Pressure Control Solenoid (377)

    • Damage to electrical terminals
    • Contamination