For 1990-2009 cars

Important: Review the system operation in order to familiarize yourself with the system functions. Refer to the following:

• | Automatic Transmission Shift Lock Control Circuit Description

• | Automatic Transmission Shift Lock Control Description

### Visual/Physical Inspection

• | Inspect for aftermarket devices which could affect the operation of the system. Refer to Checking Aftermarket Accessories in Wiring Systems.

• | Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

• | Inspect all related ground points for being clean and tight.

### Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

### Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

• | Automatic Transmission Shift Lock Control Inoperative

• | Automatic Transmission Shift Lock Control Always On with Ignition in Run