GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Blazer - 4WD - RHD 🢒 Body and Accessories 🢒 Doors 🢒 Power Door Locks Inoperative - Lockout Feature

Step

Action

Value(s)

Yes

No

Important: Some of the following steps are supported by schematics. Refer to Door Lock/Indicator Schematics .

1

Was the Power Door Locks System Check performed?

--

Go to Step 2

Refer to Power Door Locks System Check

2

Perform the body control module (BCM) diagnostic system check. Refer to Diagnostic System Check - Body Control System in Body Control System.

Are any applicable DTCs set?

--

Go to the Applicable DTC in Body Control System

Go to Step 3

3
  1. Turn the ignition switch to the LOCK position.
  2. Ensure that the key remains firmly seated in the lock cylinder.
  3. Open the drivers door.
  4. Depress the driver power lock switch on the door to the LOCK position.
  5. Repeat the step for the front passenger door.
  6. Repeat the test for one of the rear doors.

Does the drivers door lock immediately , UNLOCK?

--

Refer to Power Door Locks System Check

Go to Step 4

4

Depress the drivers door lock switch in the UNLOCK position.

Does the lock actuator UNLOCK the door?

--

Go to Step 5

Refer to Power Door Locks System Check

5
  1. Turn the ignition switch to the LOCK position.
  2. Ensure that the key is firmly seated in the cylinder.
  3. Connect a scan tool.
  4. Select BCM Data.
  5. Select Input 1.
  6. Select Key In Ignition.

Does the parameter display the specified value?

YES

Go to Step 11

Go to Step 6

6
  1. Remove the key from the cylinder.
  2. Disconnect the BCM connector C1 (BRN) and connector C2 (BLU).
  3. Use the J 35616-A in order to connect a test lamp between connector C1 terminal A2 (ORN) and connector C2 terminal B9 (LT GRN).
  4. Inspect the terminals for looseness or damage.

Does the test lamp light?

--

Go to Step 7

Go to Step 10

7

Disconnect C211 on the steering column.

Does the test lamp light?

--

Go to Step 8

Go to Step 9

8

Repair a short to ground in CKT 80 (LT GRN).

Is the repair complete?

--

Refer to Power Door Locks System Check

--

9

Replace the key alarm switch.

Is the repair complete?

--

Refer to Power Door Locks System Check

--

10

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Is the repair complete?

--

Refer to Power Door Locks System Check

--

11

Observe the scan parameter DRIVER DOOR JAMB SWITCH with the driver door open.

Does the parameter show the specified value?

ACTIVE

Go to Step 16

Go to Step 12

12
  1. Disconnect all 3 BCM connectors.
  2. Inspect the terminals for looseness or damage.
  3. Connect a test lamp between connector C3 terminal B4 (TAN) and connector C1 terminal A2 (ORN).
  4. Use the appropriate adapters from the J 35616-A .
  5. Close the driver door.

Does the test lamp light?

--

Go to Step 13

Go to Step 10

13

Disconnect the door jamb switch connector.

Does the test lamp light?

--

Go to Step 14

Go to Step 15

14

Repair a short to ground in CKT 126 (TAN).

Is the repair complete?

--

Refer to Power Door Locks System Check

--

15

Replace the drivers door jamb switch.

Is the repair complete?

--

Refer to Power Door Locks System Check

--

16
  1. Select the scan parameter REAR PASS DOOR/LIFT GLASS JAMB SWITCH.
  2. Observe the scan parameter REAR PASS DOOR/LIFT GLASS JAMB SWITCH.
  3. Open and close the appropriate doors and lift glass while observing the parameter.

Does the parameter show the specified values under the specified conditions?

INACTIVE (All of the doors are closed)

ACTIVE (One or all of the doors are open)

Go to Step 23

Go to Step 17

17
  1. Disconnect the BCM connectors.
  2. Inspect the terminals for looseness or damage.
  3. Connect a test lamp between connector C2 terminal B11 (DK BLU/WHT) and connector C1 terminal A2 (ORN).
  4. Use the appropriate adapters from the J 35616-A .
  5. Ensur that all of the doors and the endgate are closed.

Does the test lamp light?

--

Go to Step 18

Go to Step 21

18
  1. Disconnect the following door jamb switches:
    2. • The right rear jamb switch
    • The left rear jamb switch
  2. Inspect the test lamp after disconnecting each switch.

Did the test lamp turn OFF after any switch was removed?

--

Go to Step 19

Go to Step 20

19

Replace the applicable switch.

Is the repair complete?

--

Refer to Power Door Locks System Check

--

20

Repair a short to ground in CKT 727.

Is the repair complete?

--

Refer to Power Door Locks System Check

--

21

Open and close the rear doors and the endgate liftglass.

Does the test lamp light for each door?

--

Go to Step 10

Go to Step 22

22

Repair an open in CKT 727.

Is the repair complete?

--

Refer to Power Door Locks System Check

--

23
  1. Observe the DOOR HANDLE SWITCH parameter.
  2. Close all of the doors and the endgate liftglass.
  3. Open the front passenger door.

Do the parameters show the specified values under the specified conditions?

INACTIVE (All of the doors are closed)

ACTIVE (One or all of the doors are open)

Go to Step 10

Go to Step 24

24
  1. Disconnect all of the BCM connectors.
  2. Inspect the terminals for damage.
  3. Connect a test lamp between connector C1 terminal A2 (ORN) and connector C3 terminal B2 (ORN)
  4. Close all of the doors.

Does the test lamp light?

--

Go to Step 27

Go to Step 25

25

Open the front passenger door.

Does the test lamp light?

--

Go to Step 10

Go to Step 26

26

Repair an open in CKT 54?

Is the repair complete?

--

Refer to Power Door Locks System Check

--

27
  1. Disconnect C203.
  2. Disconnect the right front door handle switch.

Does the test lamp light?

--

Go to Step  29

Go to Step 28

28

Replace the right front door handle switch after performing Step 30.

Did you perform a repair?

--

Refer to Power Door Locks System Check

Go to Step 30

29

Locate and repair a short to ground in CKT 54.

Is the repair complete?

--

Refer to Power Door Locks System Check

--

30
  1. Using a test lamp, probe the body side of connector C203 to B+ at terminal G11 (ORN).
  2. Close the front doors.

Does the test lamp light?

--

Go to Step 31

Go to Step 28

31

Disconnect the left front door handle switch.

Does the test lamp light?

--

Go to Step 33

Go to Step 32

32

Replace the left front door handle switch.

Is the repair complete?

--

Refer to Power Door Locks System Check

--

33

Replace the left front door handle switch.

Is the repair complete?

--

Refer to Power Door Locks System Check

--