GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Disconnect connector C1 of the park/neutral position switch.
  2. Turn the ignition switch to the RUN position.
  3. Connect a test lamp between terminal B of the transaxle park/neutral position switch connector C1 and ground.

Does the test lamp light?

--

Go to Step 2

Go to Step 3

2

Connect a fused jumper between terminal B and terminal C of the park/neutral position switch connector C1.

Can you shift the transaxle out of PARK?

--

Go to Step 4

Go to Step 5

3

Use a testlamp in order to backprobe the underhood wiring harness junction block connector C1 between terminal F5 and ground.

Does the test lamp light?

--

Go to Step 6

Go to Step 7

4

  1. Reconnect connector C1 of the park/neutral position switch.
  2. Use a testlamp in order to backprobe the brake switch connector C2 between terminal A and ground.

Does the test lamp light?

--

Go to Step 8

Go to Step 9

5

Inspect the park/neutral position switch for proper adjustment.

If the adjustment is proper, replace the park/neutral position switch.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

6

Repair the open in CKT 539 between the underhood wiring harness junction block and the park/neutral position switch.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

7

Replace the underhood wiring harness junction block. Refer to Relay/Fuse Center Replacement in Wiring Systems.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

8

Use a test lamp in order to backprobe the brake switch connector C2 between terminal B and ground.

Does the test lamp light?

--

Go to Step 10

Go to Step 11

9

Repair the open in CKT 275 between the park/neutral position switch and the brake switch.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

10

Use a testlamp in order to backprobe the left wiring harness junction block connector C3 between terminal C9 and ground.

Does the test lamp light?

--

Go to Step 12

Go to Step 13

11

Inspect the brake switch for proper adjustment.

If the adjustment is proper, replace the brake switch.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

12

Use a test lamp in order to backprobe the left IP wiring harness junction block connector C2 between terminal C4 and ground.

Does the test lamp light?

--

Go to Step 14

Go to Step 15

13

Repair the open in CKT 1135 between the brake switch and the left wiring harness junction block.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

14

  1. Disconnect the BTSI solenoid connector.
  2. Connect a test lamp between terminal A of the BTSI solenoid connector and ground.

Does the test lamp light?

--

Go to Step 16

Go to Step 17

15

Replace the left IP wiring harness junction block. Refer to Relay/Fuse Center Replacement in Wiring Systems.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

16

Connect a test lamp between terminal A and terminal B of the BTSI solenoid connector.

Does the test lamp light?

--

Go to Step 18

Go to Step 19

17

Repair the open in CKT 1135 between the left IP wiring harness junction block and the BTSI solenoid.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

18

Replace the BTSI solenoid.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

19

Repair the open in CKT 250 between the BTSI solenoid and ground splice pack G203.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--