Volt |
||||||||
|
|
|
|||||||
| • | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Horn Relay Control | B2750 02 | B2750 04 | B2750 01 | -- |
Horn Relay Ground | - | B2750 04 | -- | -- |
The body control module (BCM) controls the horn relay by providing system voltage to the control circuit of the horn relay coil energising the relay. When the horn relay is energised, the horn relay contacts close applying voltage through the horn fuse and the horn control circuit to the horns.
The DTC can only set only when the output is actively being requested by the BCM.
The BCM detects a short to voltage in the horn relay control circuit for approximately 125 milliseconds.
The BCM detects a short to ground in the horn relay control circuit for approximately 125 milliseconds.
The BCM detects an open/high resistance in the horn relay control circuit for approximately 125 milliseconds.
The horns will sound continuously until the horns are disconnected or when the horns overheat and becomes inoperative
The horns will be inoperative.
| • | The DTC clears when the fault is no longer detected. |
| • | 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. |
Horns System Description and Operation
Control Module References for scan tool information
Vehicle in Service Mode, command the Horn Relay ON and OFF with the scan tool. The horns should turn ON and OFF when changing between the commanded states.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short circuit to voltage or open/high resistance. If the circuit tests normal, replace the K9 BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Relay Replacement : Within an Electrical Centre → Attached to Wire Harness |
| • | Control Module References for BCM replacement, programming and setup |
| ©© Copyright Chevrolet. All rights reserved |
