GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

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

Inspect the TURN-B/U fuse 16 at the IP fuse block.

Is the fuse functional?

--

Go to Step 4

Go to Step 3

3

  1. Locate the source of the overload.
  2. Replace the TURN-B/U fuse.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

4

  1. Disconnect the park/neutral position and backup lamp switch C2 connector.
  2. Place the ignition switch in the RUN position.
  3. Connect a test lampJ 35616-200 from CKT 139 (PNK) cavity C at the switch connector to ground.

Does the test lamp light?

--

Go to Step 5

Go to Step 6

5

Connect a fused jumper between CKT 139 (PNK) cavity C and CKT 275 (LT GRN) cavity B of the park/neutral position and backup lamp switch.

Does the shift lever lock in the PARK position?

--

Go to Step 7

Go to Step 8

6

Repair the open in CKT 139 (PNK) cavity C between the park/neutral position and backup lamp switch and the instrument panel fuse block.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

7

Replace the park/neutral position and backup lamp switch.

Refer to Park/Neutral Backup Switch Replacement in Transmission.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

8

  1. Reconnect the park/neutral position and backup lamp switch connector.
  2. Disconnect the Brake Pedal Position (BPP) switch connector.
  3. Connect a test lampJ 35616-200 from the brake pedal position (BPP) switch connector CKT 275 (LT GRN) cavity F to ground.

Does the test lamp light?

--

Go to Step 9

Go to Step 10

9

Connect a fused jumper between CKT 275 (LT GRN) cavity F and CKT 1135 (DK GRN/WHT) cavity E of the Brake Pedal Position (BPP) switch connector.

Does the shift lever remain unlocked in the PARK position?

--

Go to Step 11

Go to Step 12

10

Repair the open in CKT 275 (LT GRN) between the Brake Pedal Position (BPP) switch and the park/neutral position and backup lamp switch.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

11

  1. Reconnect the Brake Pedal Position (BPP) switch.
  2. Disconnect the Auto Trans Shift Lock Control solenoid connector.
  3. Connect a test lamp J 35616-200 from the auto trans shift lock control solenoid connector CKT 1135 (DK GRN/WHT) cavity A to ground.

Does the test lamp light?

--

Go to Step 13

Go to Step 14

12

Replace the Brake Pedal Position (BPP) switch assembly. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

13

Connect a test lamp J 35616-200 from CKT 1135 (DK GRN/WHT) cavity A to CKT 750 (BLK) cavity B at the auto trans shift lock control solenoid connector

Does the test lamp light?

--

Go to Step 15

Go to Step 16

14

Repair the open in CKT 1135 (DK GRN/WHT) between the Brake Pedal Position (BPP) switch and the auto trans shift lock control solenoid connectors.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

15

Replace the auto trans shift lock control solenoid assembly. Refer to Automatic Transmission Shift Lock Control Disassemble - Off Vehicle or Automatic Transmission Shift Lock Control Assemble - Off Vehicle .

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

--

16

Repair the open in CKT 750 (BLK) between the auto trans shift lock control connector and ground G110.

Is the repair complete?

--

Go to Automatic Transmission Shift Lock Control System Check

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