Workshop Manuals Factory service & repair Vauxhall
Vauxhall Astra J05 · Body Systems
05 · Body & interior

DTC B3889

Make
Vauxhall
Model
Astra J
Section
Lighting › Other Information › DTC B3889
Body SystemsDTC B3889

DTC B3889

Diagnostic Instructions

•  Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
•  Review Strategy Based Diagnosis for an overview of the diagnostic approach.
•  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

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:
  •  E5L Stop Lamp - Left
  •  E5R Stop Lamp - Right
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

Parts & tools for this job For Vauxhall Astra

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