How To Start A Remote Start Car
So, you're looking to understand how a remote start system operates. Excellent! Whether you're troubleshooting an existing system, planning an upgrade, or simply curious about the inner workings, understanding the circuit diagram is crucial. This isn't just about pushing a button and hearing your engine roar to life; it's about understanding the electrical symphony happening under the hood. With this knowledge, you can diagnose problems, make informed decisions about modifications, and even potentially save a bundle on professional repairs. We have the complete remote start system diagram file, which you can download for further study, but this article will give you a strong foundation.
Key Specs and Main Parts of a Remote Start System
A remote start system isn't a single component; it's an integrated network of modules and wiring. Let's break down the core elements:
- Remote Transmitter (Fob): The handheld device you use to initiate the remote start sequence. It transmits a radio frequency (RF) signal to the receiver.
- Remote Start Module (RSM): The brains of the operation. This module receives the signal from the fob, interprets it, and executes the necessary commands to start the engine. It houses the microcontroller and relay circuits.
- RF Receiver: This module is responsible for capturing the RF signal sent by the remote transmitter. It then forwards the decoded signal to the remote start module.
- Hood Pin Switch: A crucial safety feature. If the hood is open, this switch prevents the remote start from engaging. This avoids accidental starts while someone is working on the engine.
- Brake Switch Input: Another essential safety feature. Pressing the brake pedal disables the remote start, preventing accidental movement when the car is remotely started.
- Tachometer Wire (Tach Signal): This wire connects to the vehicle's tachometer signal, allowing the remote start module to monitor engine RPM (revolutions per minute). This is vital for ensuring the engine starts and runs smoothly.
- Ignition Wires: These wires are connected to the vehicle's ignition system, allowing the remote start module to energize the necessary circuits to start the engine (ignition, starter, accessory).
- Starter Wire: The wire directly connected to the starter solenoid. The remote start module energizes this wire to engage the starter motor.
- Immobilizer Bypass Module (if required): Modern vehicles have immobilizer systems that prevent unauthorized starting. This module bypasses the immobilizer during the remote start sequence, allowing the engine to start without the key in the ignition.
- Wiring Harness: The network of wires connecting all the components. These are typically color-coded for easy identification.
- Ground Wire: A critical component for proper electrical grounding. This ensures the remote start module has a stable reference point for voltage.
Understanding the Symbols in the Remote Start Diagram
Reading a circuit diagram is like learning a new language, but once you understand the symbols, it becomes much easier to comprehend. Here's a breakdown of common symbols you'll encounter:
- Lines: Represent wires. A solid line indicates a direct connection. Dashed lines often represent shielded wires or connections through connectors. The thickness of a line may indicate wire gauge (thicker lines are usually larger gauge wires).
- Colors: Wires are often color-coded. Common colors include red (power), black (ground), yellow (ignition), blue (starter), and green (tach). Refer to the diagram's legend for specific color assignments.
- Resistors: Represented by a zigzag line. These limit current flow in a circuit.
- Capacitors: Represented by two parallel lines. These store electrical energy.
- Diodes: Represented by a triangle with a line at one point. These allow current to flow in only one direction.
- Relays: Represented by a coil and a switch. The coil, when energized, closes the switch, completing the circuit. Relays are used to switch high-current circuits with a low-current signal.
- Ground Symbol: Represented by three horizontal lines stacked on top of each other, decreasing in size. This indicates a connection to the vehicle's chassis ground.
- Voltage Source: Represented by a circle with a + and - sign. Indicates the power supply (usually the vehicle's battery).
- Switches: Represented by a break in a line with a pivoting arm. Indicates a mechanical switch (e.g., hood pin switch, brake switch).
- Fuses: Represented by a line with a squiggle through it, often enclosed in a rectangle. Fuses protect circuits from overcurrent.
How a Remote Start System Works: The Electrical Symphony
Let's walk through the sequence of events when you press the remote start button:
- Signal Transmission: You press the remote start button on the fob. The fob transmits an RF signal encoded with a specific command.
- Signal Reception: The RF receiver in the vehicle picks up the signal. It decodes the signal and sends it to the remote start module (RSM).
- Safety Check: The RSM performs a series of safety checks. It verifies that the hood is closed (via the hood pin switch) and that the brake pedal is not pressed (via the brake switch input). If either of these conditions is not met, the remote start sequence is aborted.
- Immobilizer Bypass (if required): If the vehicle has an immobilizer system, the RSM activates the immobilizer bypass module. This module temporarily disables the immobilizer, allowing the engine to start.
- Ignition and Accessory Activation: The RSM energizes the ignition and accessory circuits, mimicking the action of turning the key in the ignition. This powers up the vehicle's electrical system.
- Starter Engagement: The RSM energizes the starter wire, engaging the starter motor. The starter motor cranks the engine until it starts.
- Tachometer Monitoring: The RSM monitors the engine RPM via the tachometer wire. Once the engine reaches a stable RPM, the RSM disengages the starter motor.
- Engine Running: The RSM continues to monitor the engine RPM. If the engine stalls, the RSM may attempt to restart it. A timer is also activated, which shuts off the engine after a predetermined period (e.g., 15 minutes).
- Brake Pedal Shutdown: Pressing the brake pedal during remote start operation will disengage remote start.
Real-World Use: Basic Troubleshooting Tips
Remote start systems can be finicky. Here are some basic troubleshooting tips:
- System Doesn't Respond: Check the battery in the remote fob. Ensure the hood is completely closed. Check the fuses in the remote start module's power supply circuit. Verify the ground connection is secure.
- Engine Cranks But Doesn't Start: Check the immobilizer bypass module (if applicable). Ensure the tachometer wire is properly connected and receiving a signal.
- Engine Starts and Immediately Stalls: This often indicates a problem with the tachometer signal. The RSM may not be able to accurately monitor the engine RPM.
- Remote Start Shuts Off Prematurely: Could be a loose connection, wiring issue, or fault with the RSM itself.
- Check All Connections: A loose connection is the most frequent cause of remote start problems.
Remember to always consult the specific wiring diagram for your vehicle and remote start system. These systems can vary significantly between makes and models.
Safety First: Identifying Risky Components
Working with automotive electrical systems can be dangerous. Here's where you need to be extra cautious:
- Battery: Disconnect the negative battery terminal before working on the electrical system. This prevents accidental shorts and potential electrocution.
- Airbags: Airbag circuits are extremely sensitive. Avoid working near airbag modules or wiring unless you have specific training and experience. Accidental deployment can cause serious injury.
- Fuel System: Avoid working near fuel lines or components. Fuel leaks can create a fire hazard.
- High-Current Wires: The wires connected to the battery and starter motor carry high currents. Handle these wires with care and ensure they are properly insulated.
- Always Double-Check Your Work: Before reconnecting the battery, carefully review your wiring connections to ensure they are correct and secure.
When dealing with any high amperage circuit, always disconnect the negative battery terminal from the chassis. This one simple precaution can save your life.
Hopefully, this has given you a solid understanding of how remote start systems work and how to interpret their circuit diagrams. Remember, we have the full diagram file available for download. Good luck, and work safely!