B2750

DTC B2750

Circuit Description

The body control module (BCM) controls the horn relay by grounding the control circuit of the horn relay coil. When the horn relay coil is grounded, the horn relay contacts close, applying voltage to the horn via the horn supply voltage circuit.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2750 Horn Relay Output

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description.






Conditions for Running the DTC

The only requirements are valid operating voltage and ground.

Conditions for Setting the DTC

The following condition exists for more than 125 milliseconds:

B2750 01

The BCM detects a short to the battery in the horn relay control when output is active.

Action Taken When the DTC Sets

B2750 01

The BCM disables the horn relay control until the next ignition cycle.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Test Description

Step 1 - Step 15:

The numbers below refer to the step numbers on the diagnostic table.
2. During the horn relay operation, listen for an audible click. Command the ON and the OFF states. Repeat the commands as necessary.
3. This step tests for voltage at the coil side of the horn relay. The horn fuse supplies power to the coil side of the horn relay.
4. This step tests for a short to voltage in the horn relay signal circuit.
5. This step verifies that the BCM is providing ground to the horn relay.