GM Service Manual Online
For 1990-2009 cars only

Automatic Transmission Shift Lock Control Always On With Ignition in RUN w/ Column Shift

Step

Action

Value(s)

Yes

No

Important: Inspect for mechanical binding and ensure that the transmission linkage is adjusted properly prior to performing this diagnostic procedure.

1

Did you perform the Auto Trans Shift Lock Control System Check?

--

Go to Step 2

Go to Automatic Transmission Shift Lock Control System Check

2

  1. Disconnect the TCC/stoplamp switch.
  2. Use a J 39200 DMM in order to test the TCC/stoplamp switch for proper operation.

Does the TCC/stoplamp switch operate properly?

--

Go to Step 4

Go to Step 3

3

Replace the TCC/stoplamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

4

  1. Turn the ignition switch to the ON position. Do not start the engine.
  2. Connect a test lamp between the TCC/stoplamp switch connector terminal F and ground.

Does the test lamp light?

--

Go to Step 6

Go to Step 5

5

Locate and repair a short to power in CKT 1135 (DK GRN/WHT).

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

6

Replace the BTSI solenoid.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

Automatic Transmission Shift Lock Control Always On With Ignition in RUN w/ Floor Shift

Step

Action

Value(s)

Yes

No

Important: Inspect for mechanical binding and ensure that the transmission linkage is adjusted properly prior to performing this diagnostic procedure.

1

Did you perform the Auto Trans Shift Lock Control System Check?

--

Go to Step 2

Go to Automatic Transmission Shift Lock Control System Check

2

  1. Disconnect the TCC/stoplamp switch.
  2. Use a J 39200 DMM in order to test the TCC/stoplamp switch for proper operation.

Does the TCC/stoplamp switch operate properly?

--

Go to Step 4

Go to Step 3

3

Replace the TCC/stoplamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

4

  1. Turn the ignition switch to the ON position. Do not start the engine.
  2. Connect a test lamp between the TCC/stoplamp switch connector terminal F and ground.

Does the test lamp light?

--

Go to Step 6

Go to Step 5

5

Locate and repair an open in the park solenoid or CKT 584 (DK GRN/BLK).

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

6

Locate and repair a short to power in the park solenoid or CKT 1135 (DK GRN/WHT).

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--