GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Place transaxle in the PARK position.
  2. Turn ignition switch to the RUN position.
  3. Disconnect the automatic transaxle control connector.
  4. Using a test lamp, connect between the automatic transaxle control connector terminal A circuit 1135 and ground.
  5. Press the brake pedal and observe the test lamp.

Does the test lamp turn off when you press the brake pedal?

--

Go to Step 3

Go to Step 2

2

Disconnect the stop lamp switch connector C2. Leave the test lamp at the same location as in step 1.

Does the test lamp illuminate?

--

Go to Step 7

Go to Step 8

3

Using a test lamp, connect between the automatic transaxle control connector terminal B circuit 434 and B+.

Does the test lamp illuminate?

--

Go to Step 10

Go to Step 4

4

  1. Disconnect the Park / Neutral Position switch connector C1.
  2. Using a test lamp, connect between the transaxle range switch connector C1 terminal D circuit 1050 and B+.

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 12

5

Using a test lamp, Connect teminal A between the stop lamp switch harness connector C2 circuit  1439 to ground.

Does the test lamp illuminate ?

Go to Step 6

Go to Step 9

6

Check for poor connection or open in circuit 434.

Is there a poor connection or open in circuit 434?

--

Go to Step 11

Go to Step 13

7

Locate and repair the short to B+ in circuit 1135. Testing for Short to Ground and Testing for Intermittent Conditions and Poor Connections In Wiring Systems.

Has the repair been completed?

--

Go to Step 14

--

8

Replace the stop lamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Has the repair been completed?

--

Go to Step 14

 

9

Repair the poor connection or open in circuit 1439.

Has the repair been completed?

--

Go to Step 14

--

10

Replace the BTSI. Refer to Automatic Transmission Shift Lock Control Disassemble - Off Vehicle in Steering Wheel Column Tilt.

Has the repair been completed?

--

Go to Step 14

--

11

Locate and repair the poor connection or open in circuit 434. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs In Wiring Systems.

Has the repair been completed?

--

Go to Step 14

--

12

Locate and repair the poor connection or open in circuit 1050. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs In Wiring Systems.

Has the repair been completed?

--

Go to Step 14

--

13

Replace Park / Neutral Position switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transaxle .

Has the repair been completed?

--

Go to Step 14

--

14

Verify that the system operates properly.

Does the system operate properly ?

--

system OK

Go to Symptoms - Automatic Transmission Shift Lock Control