Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC B2750 01: Horn Relay Coil Circuit Short to BatteryDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Horn Relay B+ | 2 | 2 | -- | -- |
Horn Relay Control | 2 | 2 | B2750 01 | -- |
Horn Control | 2 | 2 | 1 | -- |
Horn Ground | -- | 2 | 2 | -- |
1. Horn Always On 2. Horn Inoperative | ||||
Circuit/System Description
The Vehicle Interface Unit (VIU) controls the horn relay by grounding the control circuit of the horn relay coil energizing the relay. When the horn relay is energized, the horn relay contacts close applying voltage through the horn fuse and the horn control circuit to the horns.
Conditions for Running the DTC
When the horn output is actively being requested by the VIU.
Conditions for Setting the DTC
This DTC is set if the VIM attempts to assert its HORN RELAY CONTROL output to the low voltage state, but senses that the output remains in the high voltage state.
Action Taken When the DTC Sets
The VIU disables the output to the horn relay until the next ignition cycle.
Conditions for Clearing the DTC
| • | The current DTC will become history when the request for the output is removed. |
| • | The history DTC will clear after 50 consecutive fault-free ignition cycles have occurred. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Horns System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Command the horns ON and OFF with the scan tool. The horns should turn ON and OFF when changing between the commanded states. Refer to Symptoms - Horns
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for VIU replacement, setup and programming
