B2752

DTC B2752 Horn Relay Coil Circuit Low:

DTC B2752 Horn Relay Coil Circuit Low (Part 1 Of 2):

DTC B2752 Horn Relay Coil Circuit Low (Part 2 Of 2):

CIRCUIT DESCRIPTION
CKT 28 is an input to the Body Control Module (BCM). The BCM monitors CKT 28 in order to determine if the horn circuit is open or shorted to ground.

CONDITIONS FOR SETTING THE DTC
^ When CKT 28 is open or shorted to ground for approximately 3 minutes the BCM will set B2752.
^ The system voltage must be between 9.0-16.0 volts.

ACTION TAKEN WHEN THE DTC SETS
^ If CKT 28 is shorted to ground the horns will remain ON at all times.
^ If CKT 28 is open the horn will only work with the horn button on the steering wheel.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A current DTC will clear immediately after the condition for setting the fault is corrected.
^ A history DTC will clear after 100 consecutive ignition cycles without a fault present.
^ Use a scan tool in order to clear history and current DTCs.

DIAGNOSTIC AIDS
^ If the customers complaint is that the horns are always on, remove the HORN fuse located in the underhood Bussed Electrical Center (UBEC) so the system can be diagnosed without the horns on.
^ Always diagnose the first DTC listed on the scan tool.
^ The scan tool must display DTC B2752 as a current code before performing diagnostics.
^ Inspect for a sticking horn pad and or switch.
^ Perform a visual inspection for loose or poor connections at all related components.

TEST DESCRIPTION
Step number(s) below refer to the same step number(s) in the Diagnostic Table
2. This step tests CKT 28 for a short to ground.
3. This step determines if CKT 28 is shorted to ground or the BCM is faulty.
4. This step determines if the horn system works with the horn button.
5. This step tests CKT 28 for an open between the BCM and the horn relay.
6. This step determines it the UBEC has an open CKT to the horn relay.