B3950

DTC B3950

Circuit Description
Ground is applied to the turn signal switch. When the turn signal switch is placed in the turn left position, ground is applied to the 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.

Conditions for Running the DTC
The battery voltage must be between 9.0-14 volts.

Conditions for Setting the DTC
^ DTC B3950 02 A short to ground in the LR turn signal voltage supply circuit is present for longer than 0.1 seconds.
^ DTC B3950 05 A short to battery positive voltage or an open is detected in the LR turn signal voltage supply circuit is present for longer than 1 second.

Action Taken When the DTC Sets
^ If DTC B3950 02 sets, the left rear turn signal lamp does not work.
^ If DTC B3950 05 sets, if the LR turn signal voltage supply circuit is shorted to battery positive voltage the left rear turn signal lamp will be on at all times and if the LR turn signal voltage supply circuit is open the left rear turn signal lamp will be inoperative.

Conditions for Clearing the DTC
^ The DTC will clear on current status after the condition for setting the fault is corrected.
^ DTC B3950 02 will set a history code which will clear after 100 consecutive ignition cycles without a fault present.
^ History and current DTCs can be cleared using a scan tool.

Diagnostic Aids
^ Check the LR turn lamp LEDs. If the LEDs are open, DTC B3950 05 will be set.
^ If the DTC is a history DTC, the fault may be intermittent.
^ An intermittent short to ground or an open in the following locations may cause an intermittent malfunction to occur:
- The BCM
- The left rear turn signal supply voltage circuit