B2575
DTC B2575 or B2699
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 Descriptor
DTC B2575 00
- Headlamps Control Circuit Short Malfunction
DTC B2575 02
- Headlamps Control Circuit Short to Ground
DTC B2575 04
- Headlamps Control Circuit Open
DTC B2699 00
- Right Headlamp Control Circuit Short Malfunction
DTC B2699 02
- Right Headlamp Control Circuit Short to Ground
DTC B2699 04
- Right Headlamp Control Circuit Open
Diagnostic Fault Information
Circuit/System Description
When the headlight switch is placed in low beam position, the body control module (BCM) applies a voltage to the low beam headlamps (TT4) or daytime running lamps (DRL) lamps (TT2) through there respective voltage supply circuits. The headlamp control module will monitor the DRL (TT2) circuits when the BCM applies the voltage to turn on the lamps. If the headlamp control module detects that the BCM commanded on the DRL (TT2), but the headlamp control module does not detect the DRL has illuminated, DTC B2575 or B2699 will set in the headlamp control module. This indicates there is a malfunction in the TT2 headlamp assembly, or an open bulb.
Conditions for Running the DTC
The headlamps are turned ON.
Conditions for Setting the DTC
The BCM detects an over/undervoltage condition on the low beam headlamp control (TT4) or DRL control (TT2) circuits.
Action Taken When the DTC Sets
The appropriate TT4 low beam headlamps or TT2 DRL is inoperative.
Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists.
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 Views)
Description and Operation
Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
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, change between the headlamp switch ON/OFF position. The low beam headlamps (TT4) or DRL (TT2) should be ON/OFF.
Circuit/System Testing
DTC B2575 or B2699 set in Headlamp Control Module (TT2)
1. Ignition OFF, disconnect the harness connector at the appropriate headlamp.
2. Test for less than 5 ohm between the appropriate headlamp ground circuit harness connector listed below and ground.
* TT4 - E13L Headlamp Assembly - Left ground circuit harness connector terminal A
* TT4 - E13R Headlamp Assembly - Right ground circuit harness connector terminal A
* TT2 - E13L Headlamp Assembly - Left ground circuit harness connector terminal G
* TT2 - E13R Headlamp Assembly - Right ground circuit harness connector terminal G
• If greater than the specified value, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the appropriate headlamp control circuit harness connector listed below and ground.
* TT4 - E13L Headlamp Assembly - Left signal circuit harness connector terminal B
* TT4 - E13R Headlamp Assembly - Right signal circuit harness connector terminal B
* TT2 - E13L Headlamp Assembly - Left signal circuit harness connector terminal A
* TT2 - E13R Headlamp Assembly - Right signal circuit harness connector terminal A
4. Ignition ON, change between the headlamp switch ON/OFF position. The test lamp should turn ON and OFF when changing between the headlamp switch ON/OFF position.
• If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K9 Body 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 K9 Body Control Module.
5. If all the circuits test normal, replace the appropriate headlamp.
DTC B2575 or B2699 set in Headlamp Control Module (TT2)
1. Ignition OFF, remove the appropriate headlamp assembly.
2. Inspect the headlamp low beam internal wiring for open, or shorts.
• If an open or short is found, replace the headlamp assembly.
3. Remove and inspect the affected low beam bulb for an open.
• If the low beam bulb is open, replace the bulb.
4. If the low beam wiring and bulbs are normal, replace the headlamp control module.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Headlamp Replacement (Headlamp Replacement)
* Headlamp Bulb Replacement (TT2) (Headlamp Bulb Replacement (TT2))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 headlamp control module BCM replacement, setup, and programming