DTC B3889
Diagnostic Instructions
DTC Descriptors
| DTC B3889 02: Trailer Brake Lamps Circuit
Short to Ground |
| DTC B3889 04: Trailer Brake Lamps Circuit
Open |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Trailer Brake Lamps Control
|
3889 02
|
3889 04
|
-
|
-
|
|
| |
Circuit/System Description
The brake pedal position sensor is used to sense the action of
the driver application of the brake pedal. The brake pedal position
sensor provides an analog voltage signal to the body control module
(BCM). The BCM sends this message to the trailer lighting
converter. The trailer lighting converter then applies a voltage to
the trailer brake lamp through their supply circuit.
Conditions for Running the DTC
B3889 02 or B3889 04
The appropriate trailer brake lamp signal is active.
Conditions for Setting the DTC
B3889 02
The trailer lighting converter detects a short to ground on the
control circuit.
B3889 04
The trailer lighting converter detects an open control circuit.
Conditions for Clearing the DTC
The condition for setting the DTC is not longer present.
Action Taken When the DTC Sets
The appropriate trailer brake lamp is inoperative.
Reference Information
Schematic Reference
Trailer Connector/Provision 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 Trailer Brake Lamps test. The trailer
brake lamps should be ON/OFF.
Circuit/System Testing
Trailer Brake Lamps Malfunction RPO VQ9
| 1. |
Ignition OFF, test for less
than 5 Ω between the X88 Trailer Connector terminal 3, 11, 13
and ground. |
| ⇒ |
If greater than the specified value, test the
appropriate ground circuit for an open/high resistance. |
| 2. |
Connect a test lamp between
the X88 Trailer Connector terminal 6 and ground. |
| 3. |
Command the Trailer Brake
Lamps test 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 K68 Trailer Lighting 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 K68 Trailer Lighting Control
Module. |
| 4. |
If all the circuits test
normal, test the brake lamp circuit at the trailer. |
Trailer Brake Lamps Malfunction RPO D8G
| 1. |
Ignition OFF, remove the
appropriate bulb and inspect. |
| ⇒ |
If bulb is faulty, replace bulb. |
| 2. |
Ignition OFF, remove the
harness connector of the appropriate component listed below:
|
| 3. |
Test for less than 5 Ω
between the ground circuit harness connector wiring color WH and
ground. |
| ⇒ |
If greater than the specified value, test the
appropriate ground circuit for an open/high resistance. |
| 4. |
Connect a test lamp between
the appropriate control circuit terminal listed below and
ground: |
| |
• |
E5L Stop Lamp - Left wiring
color RD |
| |
• |
E5R Stop Lamp - Right wiring
color RD |
| 5. |
Command the Trailer Brake
Lamps test 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 K68 Trailer Lighting 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 K68 Trailer Lighting Control
Module. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
Control Module References for trailer lighting converter
replacement, setup and programming
|
