Refer to Body Control Module Schematics (
Cell 51: DTC B3137, B3138, B3147, and B3148 -- Power Door Locks
).
Circuit Description
The body control module (BCM) monitors and supplies an output voltage on CKT 194 in order to lock the doors. When the BCM receives an unlock signal from the remote control door lock receiver to unlock the passenger door, the BCM supplies voltage to the unlock relay and unlocks the door. If CKT 194 is shorted to battery voltage for more than 184 seconds, the BCM will set DTC B3148 as a current code.
Conditions for Setting the DTC
| • | CKT 194 is shorted to battery voltage for more than 184 seconds. |
| • | The system voltage is between 9.0-16.0 volts. |
| • | The above conditions exist for 184 seconds. |
Action Taken When the DTC Sets
The power door unlock system will not function with the remote control door lock receiver system or either door switch.
Conditions for Clearing the MIL/DTC
| • | A current DTC will clear immediately after the short to battery voltage is corrected. |
| • | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
| • | History and current DTCs may be cleared using a scan tool. |
Diagnostic Aids
| • | Always diagnose the first DTC that is listed on the scan tool. |
| • | verify that the scan tool displays DTC B3148 as a current code before you perform diagnostics. |
| • | Inspect for loose or poor connections at all of the related components. |
| • | Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step determines if the left front door lock switch is shorted to battery voltage.
-
This step determines if the right front door lock switch is shorted to battery voltage.
-
This step determines if CKT 194 is shorted to battery voltage or if the BCM is defective.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the BCM Diagnostic System Check? | -- | Go to Step 2 | |||||
Does the scan tool display DTC B3148 as a current code? | -- | Go to Step 3 | Go to Step 6 | |||||
Does the scan tool display DTC B3148 as a current code? | -- | Go to Step 4 | Go to Step 7 | |||||
Does the J 39200 DMM display battery voltage? | -- | Go to Step 5 | Go to Step 8 | |||||
5 | Locate and repair the short to battery voltage in CKT 194 (WHT) between the BCM and one of the following components:
Is the repair complete? | -- | Go to Step 9 | -- | ||||
6 | Replace the left front door lock switch. Is the repair complete? | -- | Go to Step 9 | -- | ||||
7 | Replace the right front door lock switch. Is the repair complete? | -- | Go to Step 9 | -- | ||||
8 |
Is the repair complete? | -- | Go to Step 9 | -- | ||||
9 |
Is the repair complete? | -- | -- |
