DTC B3950 or B3951
Diagnostic Instructions
DTC Descriptors
| DTC B3950 02: Left Rear Turn Signal Circuit
Short to Ground |
| DTC B3950 04: Left Rear Turn Signal Circuit
Open |
| DTC B3951 02: Right Rear Turn Signal Circuit
Short to Ground |
| DTC B3951 04: Right Rear Turn Signal Circuit
Open |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Left Rear Turn Signal
|
B3950 02
|
B3950 04
|
1
|
-
|
Right Rear Turn Signal
|
B3951 02
|
B3951 04
|
2
|
-
|
1. Left rear turn signal lamp always ON
2. Right rear turn signal lamp always ON
|
|
| |
Circuit/System Description
Ground is applied at all times to the turn signal/multifunction
switch. When the turn signal/multifunction switch is placed in
either the turn right or turn left position, ground is applied to
the body control module (BCM) through either the right turn or left
turn signal switch signal circuit. The BCM then applies a voltage
to the front/side and rear turn signal lamps through their
respective voltage supply circuits.
Conditions for Running the DTC
The appropriate turn signal is active.
Conditions for Setting the DTC
B3950 02 or B3951 02
The BCM detects a short to ground on the control circuit.
B3950 04 or B3951 04
The BCM detects an open control circuit.
Action Taken When the DTC Sets
The appropriate turn signal lamp is inoperative.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Reference Information
Schematic Reference
Exterior Lights Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, perform the appropriate Rear Turn Signal/Hazard
Lamp test. The appropriate rear turn signal/hazard lamp should be
ON/OFF.
Circuit/System Testing
| 1. |
Ignition OFF, disconnect the
harness connector at the appropriate rear turn signal lamp.
|
| 2. |
Test for less than 5 Ω
between the appropriate rear turn signal lamp ground circuit
harness connector listed below and ground: |
| |
• |
E42L Tail Lamp Assembly - Left
harness connector terminal B |
| |
• |
E42R Tail Lamp Assembly -
Right harness connector terminal C |
| ⇒ |
If greater than the specified value, test the
ground circuit for an open/high resistance. |
| 3. |
Connect a test lamp between
the appropriate rear turn signal lamp control circuit harness
connector listed below and ground. |
| |
• |
E42L Tail Lamp Assembly - Left
harness connector terminal C |
| |
• |
E42R Tail Lamp Assembly -
Right harness connector terminal B |
| 4. |
Command the appropriate rear
turn signal lamp test ON and OFF with a scan tool. The test lamp
should turn ON and OFF when changing between the commanded
states. |
| ⇒ |
If the test lamp is always ON, test the signal
circuit for a short to voltage. If the circuit tests normal,
replace the K9 Body Control Module. |
| ⇒ |
If the test lamp is always OFF, test the signal
circuit for a short to ground or an open/high resistance. If the
circuits test normal, replace the K9 Body Control Module. |
| 5. |
If all the circuits test
normal, replace the appropriate rear turn signal lamp. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|
