How Long Will Remote Start Run

Let's dive into the often-asked question: "How long will my remote start run?" This might seem like a simple query, but the answer involves a complex interplay of factors, all controlled by your vehicle's onboard computer and often influenced by aftermarket additions. Understanding the mechanics behind remote start duration isn't just about convenience; it can be crucial for diagnosing issues, troubleshooting problems, and even making informed decisions when considering aftermarket installations. This knowledge empowers you, the DIY enthusiast, to maintain and potentially even modify your vehicle's remote start system with confidence.

Key Specs and Main Parts

Before we delve into the nitty-gritty, let's define the key components that dictate how long your remote start will engage:

• Remote Start Module (RSM): The brain of the operation. It receives the signal from your key fob, interprets it, and then initiates the starting sequence.
• Tachometer Signal (Tach): This input tells the RSM that the engine is running. The RSM monitors the tach signal to ensure the engine is running and hasn't stalled. Most modern vehicles use data-bus communication for tach signal.
• Voltage Sensing: An alternative to the Tach signal. The RSM monitors the battery voltage, looking for the slight voltage increase when the alternator starts charging. Less accurate than Tach, and can cause issues.
• Run Time Timer: The pre-programmed (or user-configurable) timer that dictates the maximum duration of the remote start.
• Safety Interlocks: These are safety mechanisms, such as hood pins, brake pedal switches, and neutral safety switches (for manual transmissions), that prevent the remote start from engaging under unsafe conditions.
• Key Fob/Transmitter: The device you use to initiate the remote start sequence.
• CAN Bus (Controller Area Network): A communication network within your car that allows various electronic control units (ECUs) to communicate with each other, including the RSM.

How It Works: The Remote Start Sequence

The remote start process is a carefully orchestrated sequence of events:

1. Signal Transmission: You press the remote start button on your key fob. The fob sends a radio frequency (RF) signal to the RSM.
2. RSM Activation: The RSM receives the signal and verifies its authenticity (preventing unauthorized starts).
3. Safety Check: The RSM checks all safety interlocks. Is the hood closed? Is the brake pedal released? Is the vehicle in Park (or Neutral for manuals)? If any interlock is triggered, the remote start is aborted.
4. Starting Sequence: If all safety checks pass, the RSM engages the starter motor. Modern vehicles often use a "start pulse" strategy, where the starter is engaged for a specific duration determined by the ECU, not continuously held by the RSM.
5. Engine Monitoring: Once the engine starts, the RSM monitors the tachometer signal or voltage sensing to confirm the engine is running. If the engine fails to start after a set number of attempts (usually 2-3), the remote start sequence is aborted.
6. Run Time Management: The RSM starts the run time timer. The engine will continue to run until one of the following occurs:
   • The run time timer expires.
   • A safety interlock is triggered (e.g., the brake pedal is pressed).
   • The key is inserted into the ignition and turned to the "ON" position (this usually disengages the remote start system).
   • The remote start button is pressed again (some systems allow you to shut off the engine remotely).

The default run time is usually pre-programmed into the RSM, often ranging from 5 to 30 minutes. This duration is designed to provide sufficient time to warm up the engine and cabin without excessively idling the vehicle and wasting fuel.

Real-World Use: Troubleshooting

Here's where your understanding of the system comes into play. Let's look at some common issues and how to troubleshoot them:

• Remote start fails to engage:
  • Check the key fob battery.
  • Verify all safety interlocks are properly engaged (hood closed, parking brake set, etc.).
  • Consult the vehicle's owner's manual to ensure you're following the correct remote start procedure.
  • Check the fuses related to the remote start system.
• Remote start shuts off prematurely:
  • Suspect a faulty tach signal or voltage sensing issue. If the RSM isn't receiving a valid tach signal, it might assume the engine has stalled and shut down.
  • Check for loose wiring connections, especially those related to the tach signal.
  • A low battery voltage can sometimes cause premature shutdown.
• Remote start run time is shorter than expected:
  • The run time timer might be inadvertently adjusted (if the system allows user configuration).
  • The RSM might be detecting a false fault condition, causing it to shut down prematurely.

Safety Considerations

Working with automotive electrical systems can be dangerous. Here are some crucial safety points:

• Battery Disconnect: Always disconnect the negative battery terminal before working on any electrical components. This prevents accidental shorts and potential damage to the vehicle's electrical system.
• Airbag System: Be extremely cautious around airbag system components. Accidental deployment can cause serious injury. If you're unsure, consult a qualified technician.
• ECU/Computer Modules: Modern vehicles rely heavily on electronic control units (ECUs). Improper wiring or voltage spikes can damage these sensitive components.
• Wiring Integrity: Use proper crimping tools and connectors when splicing or modifying wiring. Poor connections can lead to intermittent problems and potential electrical fires.

Specifically regarding remote start systems, the starter motor circuit is a high-current circuit. Ensure any modifications or repairs to this circuit are performed with the appropriate gauge wiring and robust connections. A weak or undersized connection can overheat and potentially cause a fire.

Understanding Diagrams and File Availability

This document provides a general overview. However, a wiring diagram specific to your vehicle and remote start system will provide invaluable insight. Wiring diagrams use standardized symbols to represent components and connections. Here’s a quick rundown of what you might encounter:

Symbols:

• Solid Lines: Usually indicate a direct wire connection. The thickness can sometimes indicate the gauge of the wire.
• Dashed Lines: Might represent a data bus connection (like CAN bus) or a connection that is not always present (e.g., an optional feature).
• Colors: Each wire is typically identified by a specific color code (e.g., Red/White, Blue/Yellow). This helps you trace the wire's path through the vehicle.
• Component Icons: Each component (e.g., RSM, Starter Motor, Battery) is represented by a standardized icon. These icons vary slightly depending on the manufacturer, but generally, they are recognizable.
• Ground Symbols: Indicate a connection to the vehicle's chassis ground.
• Fuse Symbols: Indicate the location of a fuse in the circuit.

Typical Remote Start Diagram Sections:

• Power Supply: Shows how the RSM gets its power from the vehicle's battery.
• Starter Circuit: Illustrates how the RSM interfaces with the starter motor solenoid.
• Ignition Circuit: Details how the RSM activates the ignition system.
• Tach Signal/Voltage Sensing: Shows how the RSM monitors the engine's status.
• Safety Interlocks: Illustrates the connections to the hood pin, brake pedal switch, and other safety devices.
• CAN Bus Integration: (If applicable) Depicts how the RSM communicates with the vehicle's CAN bus.

We have a generic remote start diagram available for download. This is a general example only, and it is crucial to consult the wiring diagram specific to your vehicle and remote start system. Understanding your specific diagram is vital for accurate diagnostics and repairs.

By understanding the principles of remote start systems, you're well-equipped to troubleshoot common issues, make informed decisions about aftermarket installations, and maintain your vehicle with greater confidence. Remember to always prioritize safety and consult a qualified technician when dealing with complex or unfamiliar electrical systems. Good luck!