GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 1999 🢒 S/T Isuzu - 4WD 🢒 Body and Accessories 🢒 Doors 🢒 Power Door Lock Inoperative - Left Side Front

Step

Action

Value(s)

Yes

No

1

Did you perform the Power Door Locks System Check?

--

Go to Step 2

Go to Power Door Locks System Check

2

Use a scan tool in order to read the body control module (BCM) current diagnostic trouble codes (DTCs).

Are any current DTCs present?

--

Go to Diagnostic Trouble Code (DTC) List/Type in Body Control Systems

Go to Step 3

3

Inspect the driver door lock.

Does the driver door unlock but not lock?

--

Go to Step 4

Go to Step 7

4
  1. Remove the driver door unlock relay.
  2. Use a fused jumper wire between the driver door relay cavity terminal 4 and terminal 3.
  3. Press the driver door unlock switch then the lock switch.
  4. Reinstall the relay as needed.

Does the driver door lock?

--

Go to Step 5

Go to Step 6

5

Replace the driver door unlock relay in the body relay block.

Is the repair complete?

--

Go to Power Door Locks System Check

--

6

Replace the body relay block.

Is the repair complete?

--

Go to Power Door Locks System Check

--

7

Inspect the driver door lock.

Does the driver door lock but not unlock?

--

Go to Step 8

Go to Step 14

8
  1. Verify that the ignition switch is in the OFF position.
  2. Disconnect the BCM connector (BRN).
  3. Disconnect the connector C2 (BLU).
  4. Use a fused jumper wire in order to momentarily connect the BCM connector terminal A4 of connector C2 to ground.

Does the driver door unlock?

--

Go to Step 9

Go to Step 14

9
  1. Inspect the terminals in the BCM connectors for looseness or damage. Specifically inspect the following terminals:
    2. • C2-A4 (LT GRN)
    • C1-A3 (WHT)
  2. Repair the terminals as needed.

Did you locate and repair a terminal?

--

Go to Power Door Locks System Check

Go to Step 10

10
  1. Connect a DMM between the BCM connector C1-A3 (WHT) and ground.
  2. Depress the unlock switch on the driver door.

Does the DMM display the specified value?

Battery Volts

Go to Step 13

Go to Step 11

11

Inspect for an open in CKT 194 (WHT) between the BCM and the body relay block. Repair as needed.

Did you locate and repair an open?

--

Go to Power Door Locks System Check

Go to Step 12

12
  1. Disconnect the body relay block connector.
  2. Inspect the terminal in cavity E8 for looseness or damage.
  3. Repair the terminal as needed.

Did you repair a damaged terminal?

--

Go to Power Door Locks System Check

Go to Step 6

13

Replace the BCM.

Is the repair complete?

--

Go to Power Door Locks System Check

--

14
  1. Remove the driver door unlock relay.
  2. Connect a test lamp between the driver door unlock relay socket terminal 87A and terminal 87.

Does the test lamp light?

--

Go to Step 15

Go to Step 6

15
  1. Remove the Left Door Unlock Relay.
  2. Connect a test lamp between relay cavity 1 and cavity 2 in the body relay block using the J 35616-A .
  3. Disconnect BCM connector C2.
  4. Connect a fused jumper between the A4 (LT GRN) and ground.

Does the test lamp light?

--

Go to Step 19

Go to Step 20

16

Replace the driver door unlock relay.

Is the repair complete?

--

Go to Power Door Locks System Check

--

17

Repair an open in CKT 1391.

Is the repair complete?

--

Go to Power Door Locks System Check

--

18
  1. Disconnect the driver door lock actuator.
  2. Connect a test lamp between the driver door actuator terminal A and terminal B.
  3. Push the driver door lock switch.

Does the test lamp light?

--

Go to Step 19

Go to Step 20

19

Replace the driver door lock actuator.

Is the repair complete?

--

Go to Power Door Locks System Check

--

20
  1. Remove the driver door unlock relay.
  2. Connect a DMM between terminal 4 of the driver door unlock relay socket and terminal B of the driver door lock actuator. Ensure that the actuator is disconnected.

Is the resistance less than the specified value?

20 ohms

Go to Step 21

Go to Step 24

21
  1. Connect a digital multimeter (DMM).
  2. Inspect for continuity between the drivers door lock actuator terminal A and the driver door unlock relay terminal cavity 3.

Is continuity present?

--

Go to Step 22

Go to Step 23

22

Replace the driver door unlock relay.

Is the repair complete?

--

Go to Power Door Locks System Check

--

23

Repair the open in CKT 694.

Is the repair complete?

--

Go to Power Door Locks System Check

--

24

Repair the open in CKT 295.

Is the repair complete?

--

Go to Power Door Locks System Check

--