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DTC B2590 or B2595

DTC B2590 or B2595

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 has overviews of all diagnostic categories.


DTC Descriptors

DTC B2590 02

Left Cornering Lamp Circuit Short to Ground

DTC B2590 04

Left Cornering Lamp Circuit Open

DTC B2595 02

Right Cornering Lamp Circuit Short to Ground

DTC B2595 04

Right Cornering Lamp Circuit Open

Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
Ignition 1

2

2

-

-

Ignition 2

1

1

-

-

Left Headlamp Control

B257C 00

B257C 00

3

-

Right Headlamp Control

B257C 00

B257D 00

4

-

Headlamp Ground

-

1, 2

-

-

1. Left Cornering Lamp Inoperative

2. Right Cornering Lamp Inoperative

3. Left Cornering Lamp Always ON

4. Right Cornering Lamp Always ON



Circuit/System Description

The cornering lamp is activated automatically at vehicle speeds below 40 km/h (25 MPH) when the direction indicator is switched ON and/or when the steering angle is changed from the straight ahead position towards the side the vehicle is going to turn and passes a programmable angle threshold. The cornering lamp is deactivated automatically when the direction indicator is switched OFF and/or the steering angle has returned in the straight ahead position. The cornering lamps are deactivated at vehicle speeds above 40 km/h (25 MPH). If reverse gear is active, the cornering lamps go into park function. Both lamps will be switched on. They will switch off 20 s after leaving reverse gear or if the vehicle speed exceeds 7 km/h (4 MPH). The cornering lamps also provide a protection against overheating. When having been continuously switched on for 2 min, automatic headlamp leveling will deactivate the lamps for 2 min to enable cooling down.

Conditions for Running the DTC

The headlamp control module will attempt to switch ON the cornering lights.

Conditions for Setting the DTC

B2590 02 or B2595 02

The DTC will set when the headlamp control module detects low voltage on the sensor control circuit.

B2590 04 or B2595 04

The DTC will set when the headlamp control module detects no signal and high voltage on the sensor signal line.

Action Taken When the DTC Sets


• The headlamp control module will not attempt to switch ON the cornering lights.

• Advanced front lighting system fault indication ON


Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists.

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


• Circuit Testing

• Connector Repairs

• Testing for Intermittent Conditions and Poor Connections

• Wiring Repairs


Scan Tool Reference

Control Module References for information on diagnostic tools

Circuit/System Verification

Verify that DTC B3415 is not present.

Circuit/System Testing


1. Ignition OFF, disconnect the harness connector at the appropriate headlamp assembly.

2. Test for less than 5 Ω between the ground circuit terminal 1 and ground.

3. If greater than the specified range, test the ground circuit for an open/high resistance.

4. Disconnect the harness connector X1 at the K26 Headlamp Control Module.

5. Ignition ON, verify that a test lamp illuminates between the battery circuit terminal 10 and ground.

6. If the test lamp does not illuminate, test the battery circuit for open circuit/high resistance or short to ground.

7. Ignition OFF, reconnect the harness connector at the K26 Headlamp Control Module.

8. Ignition ON, connect a test lamp between the control circuit terminal 9 at the appropriate headlamp assembly and ground. Command the appropriate Cornering Lamp test ON and OFF with the scan tool, verify that the test lamp turns ON and OFF.

9. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K26 Headlamp Control Module.

10. 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 K26 Headlamp Control Module.

11. If all circuits test normal, replace the appropriate headlamp assembly or bulb.


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


• Headlamp Replacement

• Control Module References for headlamp control module replacement, setup, and programming