B2753

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The Body Control Module (BCM) can control the Horn Relay. The keyless Entry System can be customized to tell the BCM to toot the horn. The Theft Deterrent System can also tell the BCM to toot the horn. The BCM can do this by grounding the horn relay control circuit.

CONDITIONS FOR RUNNING THE DTC
The Body Control Module must be commanding the Horn relay to energize.

CONDITIONS FOR SETTING THE DTC
^ The BCM detects a short to battery in the horn relay control circuit.
^ The condition above must be present for more than 0.3 seconds.

ACTION TAKEN WHEN THE DTC SETS
The BCM stores DTC B2753 in memory.

CONDITIONS FOR CLEARING THE DTC
^ A short to battery in the horn relay control circuit is no longer detected by the BCM when the Horn relay is commanded to energize.
^ A history DTC B2753 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ A scan tool may be used to clear the DTC.

DIAGNOSTIC AIDS
^ If the DTC B2753 is a history DTC, the fault may be intermittent. Refer to Testing for Intermittent and Poor Connections.
^ The following conditions may cause an intermittent malfunction to occur:
- An intermittent short to battery in the horn relay control circuit
- The Horn relay coil is shorted to battery internally
- The BCM is shorted to battery internally

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
2. Listen for an audible click when the Horn relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. 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. Verifies that the Body Control Module is providing ground to the Horn relay.
5. Tests if ground is constantly being applied to the Horn relay.