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

DTC B3806

Make
Vauxhall
Model
Astra J
Section
Diagnostic Information and Procedures › Miscellaneous › DTC B3806
Body SystemsDTC B3806

DTC B3806

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 Descriptor

DTC B3806 00: High Beam and Headlamp Flash Select Circuit Malfunction

Diagnostic Fault Information



Circuit
Short to Ground
Open/High Resistance
Short to Voltage
Signal Performance

High Beam and Headlamp Flash Select Control
-
-
-
B3806 00
 

Circuit/System Description

When the turn signal/multifunction switch is placed in the high beam or flash to pass position, the body control module (BCM) will receive a ground signal through the turn signal/multifunction switch signal circuit to illuminate the high beam lamps.

Conditions for Running the DTC

High beam or flash activated

Conditions for Setting the DTC

The body control module (BCM) reports stuck turn signal/multifunction switch.

Action Taken When the DTC Sets

The high beam lamps are inoperative.

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

Reference Information


Schematic Reference

Headlights/Daytime Running Lights (DRL) 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, turn the headlamp switch in the low beam position. Push/pull the turn signal/multifunction switch between the ON/OFF position. The high beam lamps should be ON/OFF as the switch is cycled.

Circuit/System Testing

1. Ignition OFF, disconnect the S78 Turn Signal/Multifunction Switch harness connector.
2. Disconnect the negative terminal of the C1 Battery.
3. Test for less than 5 Ω between the ground circuit terminal 3 and ground.
⇒ If greater then the specified value, test the ground circuit for an open/high resistance.
4. Reconnect the negative terminal to the C1 Battery.
5. Connect the S78 Turn Signal/Multifunction Switch harness connector.
6. Disconnect the X3 harness connector at the K9 Body Control Module.
7. Connect a test lamp between B+ and the signal circuit terminal 17 X3.
8. Pull the S78 Turn Signal/Multifunction Switch between the flash and OFF position. The test lamp should turn ON and OFF as the switch is cycled.
⇒ If the test lamp is always OFF, test the signal circuit terminal 17 for a short to voltage or an open/high resistance. If the circuit test normal, replace the S78 Turn Signal/Multifunction Switch.
⇒ If the test lamp is always ON, test the signal circuit terminal 17 for a short to ground. If the circuit test normal, replace the S78 Turn Signal/Multifunction Switch.
9. If all circuits test normal, replace the K9 Body Control Module.

Component Testing

Static Test

1. Ignition OFF, disconnect the S78 Turn Signal/Multifunction Switch harness connector. S78 Turn Signal/Multifunction Switch in flash position, test for less than 5 Ω between terminal 4 and terminal 3.
⇒ If greater than the specified value, replace the S78 Turn Signal/Multifunction Switch.
2. S78 Turn Signal/Multifunction Switch in high beam position, test for less than 5 Ω between terminal 2 and terminal 3.
⇒ If greater than the specified value, replace the S30 Headlamp Switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•  Control Module References for BCM replacement, setup and programming

Parts & tools for this job For Vauxhall Astra

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