B258A
DTC B258A
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC B258A 01
-
Low Beam Control Circuit Short to Battery
DTC B258A 02
-
Low Beam Control Circuit Short to Ground
DTC B258A 04
-
Low Beam Control Circuit Open
Diagnostic Fault Information
Circuit/System Description
When the headlamp switch is placed in low beam position, the body control module (BCM) supplies battery voltage to the respective headlamp control circuits.
Conditions for Running the DTC
The headlamp switch is in the low beam position.
Conditions for Setting the DTC
B258A 01
The BCM detects a short to voltage in the headlamp low beam control circuit.
B258A 02
The BCM detects a short to ground in the headlamp low beam control circuit.
B258A 04
The BCM detects an open/high resistance in the headlamp low beam control circuit.
Action Taken When the DTC Sets
B258A 01 or B258A 04
The low beam headlamps will be inoperative.
B258A 02
The low beam headlamps will be continuously illuminated.
Conditions for Clearing the DTC
* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.
Reference Information
Schematic Reference
Headlights/Daytime Running Lights (DRL) Schematics Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Exterior Lighting Systems Description and Operation Exterior Lighting Systems
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Verification
Ignition ON, command the Headlamp Low Beam ON and OFF with a scan tool. The low beam headlamps should turn ON and OFF when changing between the commanded states.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the appropriate E13 headlamp.
2. Test for less than 5 ohms between the ground circuit terminal 1 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit terminal 3 and the ground circuit terminal 1.
4. Command Headlamp Low Beam 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 control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
5. If all circuits test normal, test or replace the E13 headlamp.
Component Testing
Relay Test
1. Ignition OFF, disconnect the KR49 headlamp low beam relay.
2. Test for 60-180 ohms between terminals 85 and 86.
• If not within the specified range, replace the KR49 headlamp low beam relay.
3. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If not the specified value, replace the KR49 headlamp low beam relay.
4. Install a 15 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.
• If greater than the specified range, replace the KR49 headlamp low beam relay.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Headlamp Replacement Headlamp Replacement
* Headlamp Bulb Replacement (TT4 Low Beam) Headlamp Bulb Replacement (TT4 Low Beam)Headlamp Bulb Replacement (TT4 High Beam) Headlamp Bulb Replacement (TT4 High Beam)
* Control Module References Programming and Relearning for BCM replacement, programming and setup