Circuit Description
The body control module (BCM) monitors and supplies an output voltage on the door lock control circuit. When the BCM receives a lock command from the remote control door lock receiver or an automatic door lock function has been activated, the BCM supplies voltage on the door lock control circuit to LOCK the doors.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B3137 All Door Lock Circuit Low |
| • | DTC B3138 All Door Lock Circuit High |
Conditions for Running the DTC
B3137
| • | The system voltage must be between 9-16 volts. |
| • | The BCM supplies a voltage signal on the door lock control circuit. |
B3138
The system voltage must be between 9-16 volts.
Conditions for Setting the DTC
B3137
| • | When the BCM supplies a voltage signal on the door lock control circuit and the door lock control circuit is shorted to ground. |
| • | The above condition must be met for 250 milliseconds. |
B3138
| • | When the door lock control circuit is shorted to battery voltage. |
| • | The above condition must be met for 904 seconds. |
Action Taken When the DTC Sets
B3137
| • | The door lock system will not LOCK the doors from the keyless entry transmitter . |
| • | The automatic door locks will not operate. |
| • | The door lock switches will not LOCK the doors. |
B3138
| • | The door lock system will not UNLOCK the doors from the keyless entry transmitter . |
| • | The door lock switches will not UNLOCK the doors. |
| • | The automatic door locks will not operate. |
Conditions for Clearing the DTC
A DTC will clear after 100 consecutive ignition cycles without a fault present.
Diagnostic Aids
| • | Perform a visual inspect for loose or poor connections at all related components. |
| • | A short to battery voltage in the door lock control circuit could be caused by a faulty door lock switch. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Listen for an audible click when the door lock relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
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This step verifies that the BCM is providing voltage to the door lock relay.
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This step tests for an open in the ground circuit to the door lock relay.
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This step tests if voltage is constantly being applied to the door lock relay.
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After replacement of the BCM you must calibrate the new module for proper operation.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Door Lock/Indicator Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Does the door lock relay turn ON and OFF with each command? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |
Does the test lamp turn ON and OFF with each command? | -- | Go to Step 4 | Go to Step 5 | |
Does the test lamp turn ON and OFF with each command? | -- | Go to Step 8 | Go to Step 10 | |
Does the test lamp remain illuminated with each command? | -- | Go to Step 7 | Go to Step 6 | |
6 | Test the door lock control circuit of the door lock relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 |
7 | Test the door lock control circuit of the door lock relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 |
8 | Inspect for poor connections at the door lock relay . 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 13 | Go to Step 11 |
9 | Inspect for poor connections at the harness connector of the body control module (BCM). 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 13 | Go to Step 12 |
10 | Repair the ground circuit of the door lock relay . Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 13 | -- |
11 | Replace the door lock relay . Did you complete the replacement? | -- | Go to Step 13 | -- |
Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 13 | -- | |
13 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
