For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
DEFINITION: Transmission shift lever does not lock in the PARK position with the ignition ON and the brake pedal not pressed.
1 | Did you perform the Automatic Transmission Shift Lock Control Symptom Tests and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Automatic Transmission Shift Lock Control
2 |

1. Connect a test lamp between the park/neutral position switch power feed circuit and the park/neutral position switch and a good ground.
2. Turn ON the ignition, with the engine OFF>

Does the test lamp illuminate?

Go to Step 3

Go to Step 8

3 | Connect a test lamp between the park/neutral signal circuit at the park/neutral position switch and a good ground. Does the test lamp illuminate? | Go to Step 4 | Go to Step 12
4 | Connect a test lamp between the park/neutral signal circuit at the automatic transmission shift lock control switch and a good ground. Does the test lamp illuminate? | Go to Step 5 | Go to Step 9
5 | Connect a test lamp between the automatic transmission shift lock signal circuit at the automatic transmission shift lock control switch and a good ground. Does the test lamp illuminate? | Go to Step 6 | Go to Step 14
6 | Connect a test lamp between the automatic transmission shift lock signal circuit at the automatic transmission shift lock control solenoid and a good ground. Does the test lamp illuminate? | Go to Step 7 | Go to Step 10
7 | Connect a test lamp between the automatic transmission shift lock control solenoid ground circuit at the automatic transmission shift lock control solenoid and battery positive voltage (B+). Does the test lamp illuminate? | Go to Step 16 | Go to Step 11
8 | Repair the open or high resistance in the park neutral switch power feed circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 18 | --
9 | Repair the open or high resistance in the park neutral switch signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 18 | --
10 | Repair the open or high resistance in the automatic transmission shift lock control signal circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 18 | --
11 | Repair the open or high resistance in the automatic transmission shift lock control solenoid ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 18 | --
12 | Inspect for poor connections at the park/neutral position switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 13
13 | Replace the park/neutral position switch. Refer to Park/Neutral Position Switch Replacement Did you complete the replacement? | Go to Step 18 | --
14 |

• | Inspect for proper automatic transmission shift lock control switch adjustment. Refer to Stop Lamp Switch Adjustment in Hydraulic Brakes.

• | Inspect for poor connections at the automatic transmission shift lock control switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 18

Go to Step 15

15 | Replace the automatic transmission shift lock control switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes. Did you complete the replacement? | Go to Step 18 | --
16 | Inspect for poor connections at the automatic transmission shift lock control solenoid. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 17
17 | Replace the automatic transmission shift lock control solenoid Did you complete the replacement? | Go to Step 18 | --
18 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2