Automatic Transmission Shift Lock Control Inoperative. Chevrolet Chevy C Silverado

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 1999 🢒 Chevy C Silverado - 2WD 🢒 Steering 🢒 Steering Wheel and Column - Tilt 🢒 Automatic Transmission Shift Lock Control Inoperative

Step

Action

Value(s)

Yes

IMPORTANT:

•

Inspect the condition of BU/LPS and the automatic transmission shift lock control fuse (located in the underhood bussed electrical center (UBEC)). If any fuse is open, replace the fuse. Retest system for intermittent fuse failure. If the fuse continues to fail locate and repair the source of the overload. Refer to Power Distribution Schematics in Wiring Systems.

•	Verify that ground G203 is clean and tight.

•	Verify that the park/neutral position switch is adjusted properly.

Set the parking brake.
Turn ignition switch to the run position.
Place the transmission in reverse.

Do the backup lamps operate?

Go to Step 5

Go to Step 2

Locate the open in CKT 839 (PNK) between the park/neutral position switch and the B/U LPS fuse.

Did you find an open?

Go to Step 3

Go to Step 4

Repair the open in CKT 839 (PNK) between the park/neutral position switch and the B/U LPS fuse.

Is the repair complete?

Go to Steering Column Lock Diagnostic System Check

Replace the park/neutral position switch. Refer to Park/Neutral Position Switch Replacement in Automatic Transmission-4L60-E, or Park/Neutral Position Switch Replacement in Automatic Transmission-4L80-E.

Is the repair complete?

Go to Steering Column Lock Diagnostic System Check

Place the transmission in park.
Using the appropriate probe from the J 35616 connector test adapter kit, connect a test lamp between the automatic transmission shift lock control fuse and ground.

Does the test lamp light?

Go to Step 9

Go to Step 6

Locate the open in CKT 275 (LT GRN) between the automatic transmission shift lock control fuse and the park/neutral switch.

Did you find an open?

Go to Step 7

Go to Step 8

Repair the open in CKT 275 (LT GRN) between the automatic transmission shift lock control fuse and the park/neutral switch.

Is the repair complete?

Go to Steering Column Lock Diagnostic System Check

Is the repair complete?

Go to Steering Column Lock Diagnostic System Check

Disconnect the stoplamp switch.
Connect a test lamp between CKT 584 (LT GRN/BLK) cavity E and ground.
Turn the ignition switch to the RUN position.

Does test lamp light?

Go to Step 10

Go to Step 13

Reconnect the stoplamp switch assembly.
Disconnect connector C201A.
Connect a test lamp between CKT 1135 (DK GRN/WHT) cavity A17 and ground.

Does test lamp light?

Go to Step 11

Go to Step 14

Connect a test lamp between CKT 1135 (DK GRN/WHT) cavity A17 and CKT 1850 (BLK) cavity A16.

Does test lamp light?

Go to Step 12

Go to Step 17

Replace the automatic transmission shift lock control solenoid. Refer to Steering Shaft, Lower Bearing, and Jacket - Disassemble - Off Vehicle .

Is the repair complete?

Go to Steering Column Lock Diagnostic System Check

Locate and repair the open in CKT 584 (LT GRN/BLK) between the stoplamp switch and the BTSI fuse.

Is the repair complete?

Go to Steering Column Lock Diagnostic System Check

Connect a self powered test lamp between CKT 1135 (DK GRN/WHT) cavity A17 and pin F at the stoplamp switch.

Does test lamp light?

Go to Step 15

Go to Step 16

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

Is the repair complete?

Go to Steering Column Lock Diagnostic System Check

Locate and repair the open in CKT 1135 (DK GRN/WHT) between C201A and the stoplamp switch.

Is the repair complete?

Go to Steering Column Lock Diagnostic System Check

Locate and repair the open in CKT 1850 (BLK) between C201A and G203.

Is the repair complete?

Go to Steering Column Lock Diagnostic System Check