Circuit Description
When the turn signal/multifunction switch is placed in the right turn position, ground is applied to the body control module (BCM) through the right turn signal switch circuit. The BCM then applies a pulsating voltage to the RF and RR turn signal lamps through the RF and RR turn signal voltage supply circuits.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B3949 Right Front Turn Signal Circuit
DTC Symptom | DTC Symptom Descriptor |
|---|---|
02 | Short to Ground |
05 | Open or Short to Voltage |
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
| • | DTC B3949 02 will set when the BCM detects a short to ground in the RF turn signal voltage supply circuit. |
| • | DTC B3949 05 will set when the BCM detects an open or short to voltage in the RF turn signal voltage supply circuit. |
Action Taken When the DTC Sets
| • | When DTC B3949 02 is present, the RF turn signal lamp will not operate. |
| • | When DTC B3949 05 is present, the RF turn signal lamp will be ON at all times for a short to voltage condition. For an open condition, the RF 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 RF turn signal bulb. If the bulb is open, DTC B3949 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 .
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Exterior Lights Schematics Connector End View Reference: Master Electrical Component List | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Is DTC B3949 02 present? | Go to Step 3 | Go to Step 5 |
3 |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 11 |
4 | Locate and repair a short to ground in the RF turn signal voltage supply circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 10 |
5 | Is the RF turn signal lamp ON at all times? | Go to Step 6 | Go to Step 8 |
6 |
Does the RF turn signal lamp turn OFF? | Go to Step 11 | Go to Step 7 |
7 | Locate and repair a short to battery voltage in the RF turn signal lamp voltage supply circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 10 |
8 |
Does the test lamp illuminate? | Go to Step 11 | Go to Step 9 |
9 | Locate and repair an open or high resistance in the RF turn signal lamp voltage supply circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 10 |
10 | Inspect for poor connections at the harness connector of the underhood fuse block. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
11 | Inspect for poor connections at the C1 harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
12 | Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement . Did you complete the replacement? | Go to Step 14 | -- |
13 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 14 | -- |
14 |
Does the DTC reset? | Go to Step 2 | System OK |
