Refer to Door Lock/Indicator Schematics .
Circuit Description
The body control module (BCM) controls the locking function of the door locks. The BCM grounds the door unlock feed circuit, switches battery power to the door lock feed circuit, which energizes all of the door lock motors to lock.
Conditions for Running the DTC
The BCM must not be commanding all of the door lock motors to lock.
Conditions for Setting the DTC
| • | The BCM detects a short to battery in the door lock feed circuit while not commanding all of the door lock motors to lock. |
| • | The condition above must be present for more than 0.3 seconds. |
Action Taken When the DTC Sets
The BCM stores DTC B3138 in memory.
Conditions for Clearing the DTC
| • | A short to battery in the door lock feed circuit is no longer detected by the BCM. |
| • | A history DTC B3138 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present. |
| • | A scan tool may be used to clear the DTC. |
Diagnostic Aids
| • | If the DTC B3138 is a history DTC, the fault may be intermittent. Refer to Intermittents and Poor Connections. |
| • | The following conditions may cause an intermittent malfunction to occur: |
| - | An intermittent short to battery in the door lock feed circuit |
| - | One of the door lock motors is intermittently shorted to battery internally |
| - | The BCM is intermittently shorted to battery internally |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
-
Listen for an audible noise when the door lock motors are commanded to lock . Command the door lock motors to lock and unlock. Repeat the commands as necessary.
-
Verifies that the Body Control Module is providing voltage to the door lock motors. Test the DR LK Fuse before this step is performed.
-
Tests for an open in the ground circuit to the door lock motors.
-
Tests if voltage is constantly being applied to the door lock motors.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check for the door system? | -- | Go to Step 2 | |
Do the door lock motors lock and then unlock with each command? | -- | Go to Diagnostic Aids | Go to Step 3 | |
Does the test lamp flash when the door lock motors are commanded to lock. | -- | Go to Step 4 | Go to Step 5 | |
Does the test lamp flash with each command? | -- | Go to Step 8 | Go to Step 10 | |
Does the test lamp remain lit with each command? | -- | Go to Step 7 | Go to Step 6 | |
6 | Test the lock control circuit of the door lock motors 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 lock control circuit of the door lock motors 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 | Test the lock control circuit in each door harness for a short to ground if DTC B3137 is set, or a short to battery if DTC B3138 is set. Refer to Circuit Testing and Wiring 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. 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 motor on the body harness side. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 13 | -- |
11 | Find and replace the defective door lock motor. Refer to the following procedures: Did you complete the repair? | -- | Go to Step 13 | -- |
12 |
Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
