B3948
DTC B3948
CIRCUIT DESCRIPTION
When the turn signal/multifunction switch is placed in the left turn position, ground is applied to the body control module (BCM) through the left turn signal switch circuit. The BCM then applies a pulsating voltage to the LF and LR turn signal lamps through the LF and LR turn signal voltage supply circuits.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B3948 Left Front Turn Signal Circuit
This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information. DTC Symptom Description
CONDITIONS FOR RUNNING THE DTC
Battery voltage must be between 9-16 volts.
CONDITIONS FOR SETTING THE DTC
- DTC B3948 02 will set when the BCM detects a short to ground in the LF turn signal voltage supply circuit.
- DTC B3948 05 will set when the BCM detects an open or short to voltage in the LF turn signal voltage supply circuit.
ACTION TAKEN WHEN THE DTC SETS
- When DTC B3948 02 is present, the LF turn signal lamp will not operate.
- When DTC B3948 05 is present, the LF turn signal lamp will be ON at all times for a short to voltage condition. For an open condition, the LF turn signal lamp will be inoperative.
CONDITIONS FOR CLEARING THE DTC
- The condition responsible for setting the DTC no longer exists.
- You issue a scan tool CLEAR DTCs command.
- A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.
DIAGNOSTIC AIDS
Check the LF turn signal bulb. If the bulb is open, DTC B3948 05 will set as current only.
Thoroughly inspect the wiring and connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis causing part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Component Tests and General Diagnostics
TEST
