Automatic Transmission External Controls Diagnosis

Inspection and Verification 

1. Verify the customer concern by operating the transmission external control.
2. Visually inspect for obvious signs of mechanical and electrical damage; see the following chart:
   VISUAL INSPECTION CHART
   
   

   Mechanical	Electrical
   Damaged shift lock actuator Damaged transmission control switch (TCS)	Failed fuse(s) Damaged wiring harness Loose or corroded connections

3. If the concern is not visually evident, determine the symptom and proceed to the Diagnostic Index.