Schematic Reference: Diagnostic Starting Point - Automatic Transmission Shift Lock Control Automatic Transmission Shift Lock Control Schematics in Automatic Transmission - 6L80

DEFINITION: Transmission shift lever does not move with ignition ON and the brake pedal pressed.

Did you perform the Symptoms - Automatic Transmission Shift Lock Control tests and perform all necessary inspections?

Go to Step 2

Go to Symptoms - Automatic Transmission Shift Lock ControlSymptoms - Automatic Transmission Shift Lock Control in Automatic Transmission - 6L80

1. Turn ON the ignition, with the engine OFF.
2. Press and hold the brake pedal.
3. Attempt to move the shift lever out of the PARK position.

Does the shift lever move out of the PARK position?

Go to Testing for Intermittent Conditions and Poor ConnectionsTesting for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Do the stop lamps operate properly?

Go to Step 4

Go to Diagnostic Starting Point - LightingDiagnostic Starting Point - Lighting Systems

1. Connect a test lamp between the shiftlock control solenoid feed circuit of the shiftlock control relay (terminal 4) and ground.
2. Turn ON the ignition, with the engine OFF.
3. Press and hold the brake pedal.

Does the test lamp illuminate?

Go to Step 7

Go to Step 5

Test the shift lock control relay supply voltage circuit for an open or high resistance. Refer to Circuit Testing Circuit Testing and Wiring Repairs Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

Test the shift lock control relay brake switch input circuit for a short to B+. Refer to Circuit Testing Circuit Testing and Wiring Repairs Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 10

Test the shift lock control solenoid feed circuit for an open or high resistance. Refer to Circuit Testing Circuit Testing and Wiring Repairs Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 8

Test the shift lock control solenoid supply voltage circuit for an open or high resistance. Refer to Circuit Testing Circuit Testing and Wiring Repairs Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 9

Test the shift lock control solenoid ground circuits for an open or high resistance. Refer to Circuit Testing Circuit Testing and Wiring Repairs Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 11

Inspect for poor connections at the shift lock control relay. Refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections and Connector Repairs Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 12

Inspect for poor connections at the shift lock control solenoid. Refer to Testing for Intermittent Conditions and Poor ConnectionsTesting for Intermittent Conditions and Poor Connections and Connector Repairs Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 13

Replace the shift lock control relay. Refer to Relay Replacement - Relay within an Electrical Center Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 14

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Replace the shift lock control solenoid. Refer to Automatic Transmission Shift Lock Control Actuator ReplacementAutomatic Transmission Shift Lock Actuator Replacement in Automatic Transmission - 6L80.

Did you complete the replacement?

Go to Step 14

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Operate the system in order to verify the repair.

Did you find and correct the condition?

System OK

Go to Step 2