Owner's Problem Description
The owner has a 2007 Ford Mustang V6 automatic with the Pony package. They received an extra remote for a remote start system when purchasing the vehicle, which has about 3,000 miles. The remote start does not function properly; when the button is pressed, the car's electronics activate, but it honks five times and then turns off. The owner has been unable to get the remote start to work over several months and seeks assistance.
Professional Technical Analysis
The 2007 Ford Mustang V6 automatic is equipped with a factory-installed remote start system. The vehicle has approximately 3,000 miles. The symptom presented is that when the remote start button is pressed, the vehicle's electronics activate temporarily, followed by five horn honks, and then it shuts down. This behavior typically indicates an issue with one of the safety interlocks associated with the remote start system. Common causes include a malfunctioning hood switch, brake switch, or issues with the remote start module itself. The interconnections within the system are critical; for example, the remote start module relies on signals from both the hood and brake switches to ensure the vehicle is safe to start. If a switch is triggered incorrectly (for instance, if the hood is not closed properly), the system will prevent engine start as a safety precaution. The vehicle may also have diagnostic trouble codes (DTCs) stored in the PCM related to the remote start failure, which can be retrieved using an OBD-II scanner or the GeekOBD APP. A thorough examination of the wiring and connections related to the remote start module is necessary, along with testing the functionality of the hood and brake switches. These switches should show continuity when closed; a faulty switch could prevent the remote start from engaging. Finally, the vehicle's current condition should be assessed, ensuring that all systems are functioning properly to avoid any safety risks.
Possible Causes
Most common causes (ordered by frequency):
- Hood Switch Malfunction: The hood switch is a safety feature that prevents the engine from starting if the hood is open. If the switch is stuck or malfunctioning, it may falsely indicate that the hood is open, triggering the remote start system to shut down. A functional test involves checking for continuity when the hood is closed (should be closed circuit) and ensuring there are no broken wires or corrosion at the switch connection. - Remote start system failure with horn beeping five times indicates potential hood switch issue; continuity test needed.
- Brake Switch Issue: The brake switch must be engaged to allow the engine to start via remote. If the brake switch is faulty, even if the remote start is activated, the system will not permit the start sequence. Testing the brake switch involves checking for proper operation (should show continuity when the brake pedal is pressed) and inspecting wiring for damage or disconnection. - No start condition when remote is pressed, indicating brake switch may not be functioning correctly; continuity test is necessary.
- Remote Start Module Failure: The remote start module may be faulty or not properly connected. This module interprets signals from safety switches and initiates the start sequence. A thorough inspection of the module's wiring and connectors is necessary, looking for loose connections or damage. If the module is defective, it may need replacement. - Remote start attempts result in immediate shutdown and horn beeping, suggesting possible module malfunction; visual inspection and testing required.
Diagnostic Steps
Professional Diagnosis Process
Follow these systematic steps to accurately diagnose the issue. Each step builds on the previous one to ensure accurate diagnosis.
- STEP 1 - Visual Inspection: Begin with a thorough visual inspection of the remote start module and associated wiring. Look for any signs of damage, loose connections, or corrosion. Ensure that the hood switch and brake switch are accessible for further testing.
- STEP 2 - Hood Switch Testing: Disconnect the hood switch and use a multimeter to test for continuity. It should read closed circuit when the hood is closed. If it does not, replace the switch (OEM P/N 6R3Z-16700-A).
- STEP 3 - Brake Switch Testing: Similarly, test the brake switch by checking for continuity while pressing the brake pedal. A reading of closed circuit confirms proper function. If it fails, replace the brake switch (OEM P/N 3R3Z-13480-AB).
- STEP 4 - Remote Start Module Check: If the switches are functional, inspect the remote start module itself. Check all connections and consider testing the module with an OBD-II scanner to retrieve any fault codes. If found faulty, replace the module (OEM P/N 7R3Z-19G366-AB).
