NOTICE: The following step uses a test light to simulate normal circuit loads. Use only a Rotunda Test Lamp (SGT27000) or 250-300mA incandescent bulb test lamp. To avoid connector terminal damage, use the Rotunda Flex Probe kit for the test lamp probe connection to the vehicle. Do not use the test lamp probe directly on any connector. Disconnect Horn C131 or C1102. For C131, connect:
Click to display connectors
Positive Lead | Measurement / Action | Negative Lead |
|---|---|---|
C131-2 | C131-1 |
For C1102, connect:
Click to display connectors
Positive Lead | Measurement / Action | Negative Lead |
|---|---|---|
C1102-2 | C1102-1 |
Momentarily connect a fused jumper wire:
Positive Lead | Measurement / Action | Negative Lead |
|---|---|---|
Horn relay pin socket 3 | Horn relay pin socket 5 |
Does the test light momentarily illuminate?
Yes | GO to A5 |
|---|---|
No | GO to A8 |
A5 CHECK THE HORN CIRCUIT OPERATION USING THE BCM (BODY CONTROL MODULE) HORN_RELAY PID (PARAMETER IDENTIFICATION)
Install the horn relay. Ignition ON. Using a diagnostic scan tool, view BCM Parameter Identifications (PIDs). Select the active command BCM HORN_RELAY PID and command the horn ON and then OFF.
Does the test light momentarily illuminate?
Yes | INSTALL a new horn. REFER to: Horn (413-06 Horn, Removal and Installation). |
|---|---|
No | GO to A6 |
A6 CHECK THE HORN RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
Ignition OFF. Remove the horn relay. Disconnect BCM C2280F. Ignition ON. Measure:
Click to display connectors
Positive Lead | Measurement / Action | Negative Lead |
|---|---|---|
Horn relay pin socket 2 | Ground |
Is any voltage present?
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.