Diagnostic Aids
A short to ground in any door lock or unlock control circuit will most likely open the 15-amp DR LK/TRUNK fuse located in the instrument panel (I/P) fuse block and cause all door lock functions to become inoperative. However, if the lock or unlock control circuit is shorted to ground and the DR LK/TRUNK fuse does not open, the most likely affect will be that all door locks will be inoperative in one direction, i.e. if the unlock control circuit is shorted to ground, all doors may lock, but will not unlock, or, if the lock control circuit is shorted to ground, all doors may unlock, but will not lock.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step determines if the malfunction may be caused by a short to ground in the battery positive voltage circuit of the body control module (BCM). The BCM provides the voltage needed to power all door lock actuator control circuits. A short to ground in the battery positive voltage circuit of the BCM will open the DR LK/TRUNK 15-amp fuse in the I/P fuse block and cause all door lock functions to become inoperative.
While following the steps of this procedure, be sure you are testing the battery voltage circuit of the BCM that is associated with the door lock system. Use the door lock actuator schematics at the front of the doors section in order to correctly identify the appropriate circuit.
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This step determines if the malfunction may be caused by an open in the battery positive voltage circuit of the BCM. The BCM provides the voltage needed to power all door lock actuator control circuits. An open in the BCM battery positive voltage circuit of the BCM will cause all door lock functions to be inoperative.
While following the steps of this procedure, be sure you are testing the battery voltage circuit of the BCM that is associated with the door lock system. Use the door lock actuator schematics at the front of the doors section in order to correctly identify the appropriate circuit.
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This step determines if the malfunction may be caused by an open in the ground circuit of the BCM. The BCM provides the ground path for all door lock actuator control circuits.
While following the steps of this procedure, be sure you are testing the ground circuit of the BCM that is associated with the door lock system. Use the door lock actuator schematics at the front of the doors section in order to correctly identify the appropriate circuit.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Door Lock/Indicator Schematics Connector End View Reference: Vehicle Access Connector End Views DEFINITION: All door lock functions are inoperative from any switch or key FOB. | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 | Verify that the all doors and switches power door locks inoperative fault is present. Does the power door locks system operate normally? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 | Is the DR LK/TRUNK fuse open? | Go to Step 4 | Go to Step 5 |
Test the battery positive voltage circuit of the body control module (BCM) for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 8 | |
5 | Test the door lock and unlock control circuits for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 6 |
Test the battery positive voltage circuit of the BCM for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 7 | |
Test the ground circuit of the BCM for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 10 | |
8 | Test the door lock actuator lock control circuits for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 9 |
9 | Test the door lock actuator unlock control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 11 |
10 | Test the door lock actuator lock control circuit for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
11 | Test the driver door lock actuator unlock control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
12 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
13 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 14 | -- |
14 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
