GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Door Control Module Schematics

Connector End View Reference: Power Door Systems Connector End Views

1

Did you perform the Door Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Door Systems

2

Important:: Verify that the linkage between the door lock cylinder and the door lock is not loose or disconnected.

Verify that the power door locks key cylinder switches inoperative fault is present.

Does the power door locks key cylinder switches system operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Does the power door locks system operate normally?

Go to Step 4

Go to Symptoms - Doors

4

  1. Install a scan tool.
  2. With a scan tool, observe the Door Key Unlock parameter in the appropriate door control module Inputs data list.
  3. Insert the door lock key in the door lock cylinder.
  4. Turn the door lock key to the Unlock position.

Does the scan tool display Active?

Go to Step 8

Go to Step 5

5

  1. Install a scan tool.
  2. Disconnect the appropriate door latch C1 harness connector.
  3. Connect a 3 amp fused jumper wire between the door key switch signal circuit and the ground circuit of the appropriate door latch C1 harness connector.
  4. With a scan tool, observe the Door Key Unlock parameter in the appropriate door control module Inputs data list.

Does the scan tool display Active?

Go to Step 9

Go to Step 6

6

  1. Disconnect the 3 amp fused jumper wire.
  2. Probe the door key switch signal circuit of the appropriate door latch C1 harness connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 10

7

Probe the ground circuit of the appropriate door latch C1 harness connector with a test lamp that is connected to B+.

Does the test lamp illuminate?

Go to Step 

Go to Step 11

8

Inspect for poor connections at the harness connectors of the appropriate door module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 12

9

Inspect for poor connections at the harness connectors of the appropriate door latch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 13

10

Repair the open in the appropriate door key switch signal circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 14

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11

Repair the open in the appropriate ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 14

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12

Replace the appropriate door module. Refer to Door Control Module Replacement .

Did you complete the replacement?

Go to Step 14

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13

Replace the appropriate door latch. Refer to Door Lock Replacement .

Did you complete the replacement?

Go to Step 14

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14

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2