2010 Cadillac Truck SRX AWD V6-3.0L Page 304
瀚慖f the E4G headlamp-left low beam and the E4H headlamp-right low beam do not activate, test the control circuit for a short to ground or
an open/high resistance.
6. Connect a test lamp between the B+ circuit terminal 86 and the control circuit terminal 85.
7. Ignition ON, command the Low Beam Lamps ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between
the commanded states.
瀚慖f the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 BCM.
瀚慖f the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace
the K9 BCM.
8. If all circuits test normal, test or replace the KR49 headlamp low beam relay.
Component Testing
Relay Test
1. Ignition OFF, disconnect the KR49 headlamp low beam relay.
2. Test for 60-180 ohm between terminals 85 and 86.
瀚慖f 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
瀚慖f not the specified value, replace the KR49 headlamp low beam relay.
4. Install a 15A 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 ohm between terminals 30 and 87.
瀚慖f greater than the specified range, replace the KR49 headlamp low beam relay.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Relay Replacement (Attached to Wire Harness) (See: Power and Ground Distribution/Power Distribution Relay/Service and Repair/Relay
Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (See: Power and Ground Distribution/Power
Distribution Relay/Service and Repair/Relay Replacement (Within an Electrical Center))
* Control Module References (See: Testing and Inspection/Programming and Relearning) for BCM replacement, setup and programming
B260A
DTC B260A
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptor
DTC B260A 00
- Backlight and Display Dimming Request Circuit Malfunction
Diagnostic Fault Information
