DTC B2752 Horn Relay Coil Circuit Low. GMC Truck Jimmy

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 Jimmy - 4WD 🢒 DTC 🢒 DTC B2752 Horn Relay Coil Circuit Low

CKT 28 is an input to the BCM. The BCM monitors CKT 28 in order to determine if the horn circuit is shorted to ground.

•	When CKT 28 is shorted to ground for more than 184 seconds.

•	The system voltage is between 9.0-16.0 volts.

•	The above conditions exist for 184 seconds.

The horn will remain ON at all times.

•	A current DTC will clear after the next ignition cycle that does not contain a fault.

•	A history DTC will clear after 100 consecutive ignition cycles without a fault present.

•	History and current DTCs may be cleared using a scan tool.

•	Always diagnose the first DTC that is listed on the scan tool.

•	Verify that the scan tool displays DTC B2752 as a current code before you perform diagnostics.

•	Determine if the horn pad or the horn switch sticks.

•	Inspect for loose or poor connections at all of the related components.

•	Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

The number below refers to the step number on the diagnostic table.

This step tests CKT 28 for a short to ground.

Step

Action

Value(s)

Yes

Did you perform the BCM Diagnostic System Check?

Turn the ignition switch to the OFF position.
Disconnect the brown BCM connector C2 (BRN). Remove the comb from the connector.
Use a test lamp in order to backprobe between CKT 28 (BLK) cavity A9 and a good power source.

Does the test lamp light?

Locate and repair the short to ground in CKT 28 (BLK) between the following components:

•	The horn relay

•

The BCM

•	The horn switch

Is the repair complete?

Is the repair complete?

Clear the DTCs.

Is the repair complete?