Remote start is a fantastic convenience, especially on cold winter mornings or sweltering summer afternoons. Pre-heating or pre-cooling your car before you even step inside is a luxury many of us have come to rely on. However, a non-functional remote start key fob can be incredibly frustrating. This comprehensive guide will walk you through common reasons why your remote start might not be working and provide detailed troubleshooting steps to get it back in action.
Understanding How Remote Start Works
Before diving into troubleshooting, it’s helpful to understand the basic principles of how a remote start system operates. Most factory-installed remote start systems consist of a receiver in the vehicle, an antenna to pick up the signal from the key fob, and a control module that interprets the signal and initiates the starting sequence.
The key fob itself contains a transmitter that sends a coded radio frequency signal to the receiver in your car. This signal is encrypted to prevent unauthorized access and theft. Upon receiving the correct signal, the control module verifies that all safety parameters are met (e.g., the car is in Park, the hood is closed) before engaging the starter.
Aftermarket remote start systems operate similarly but are installed by a third party and may have different features and functionalities.
Common Reasons Why Your Remote Start Isn’t Working
Several factors can contribute to a malfunctioning remote start. Identifying the potential cause is the first step towards finding a solution.
Dead or Weak Battery in the Key Fob
This is often the simplest and most common culprit. Just like your car battery, the battery in your key fob eventually depletes. A weak battery might send a signal that’s too weak for the receiver to pick up.
Out of Range
Remote start systems have a limited range. Obstacles like buildings, trees, and other vehicles can interfere with the signal.
Hood Pin Switch Issues
Most remote start systems are designed with safety in mind. They won’t activate if the hood is open. The hood pin switch is a sensor that detects whether the hood is properly closed. If this switch is faulty or the hood isn’t fully latched, the remote start will be disabled.
Door Ajar Sensor Problems
Similar to the hood pin switch, door ajar sensors prevent remote start activation if a door is not completely closed. A faulty sensor or a door that’s not properly latched can prevent the system from working.
Check Engine Light
Many vehicles are programmed to disable the remote start function when the check engine light is illuminated. This is because certain engine problems could be exacerbated by remote starting.
System Lockout
Some remote start systems have a lockout feature that can be triggered by multiple failed start attempts or specific error codes.
Brake Switch Malfunction
The brake switch is another safety feature. If the system detects that the brake pedal is being pressed, it will prevent the remote start from engaging.
Faulty Wiring or Connections
In aftermarket systems, especially those that have been installed for a while, loose or corroded wiring connections can disrupt the signal path.
Antenna Problems
If the antenna that receives the signal from the key fob is damaged or disconnected, the remote start won’t function.
Programming Issues
Sometimes, the key fob needs to be reprogrammed to the vehicle’s system, especially after a battery replacement or if there has been an issue with the car’s computer.
Troubleshooting Steps to Get Your Remote Start Working
Now that we’ve covered the common causes, let’s go through the steps you can take to diagnose and fix the problem.
Replace the Key Fob Battery
This is the easiest and most logical first step.
- Identify the Battery Type: Consult your owner’s manual or search online for the correct battery type for your key fob. Common types include CR2032, CR2025, and CR2016.
- Open the Key Fob: Most key fobs have a small slot or indentation that allows you to pry them open. You may need a small screwdriver or a plastic prying tool. Be careful not to damage the casing.
- Remove the Old Battery: Take out the old battery, noting the orientation (positive and negative sides).
- Insert the New Battery: Insert the new battery in the correct orientation.
- Reassemble the Key Fob: Carefully snap the key fob back together.
- Test the Remote Start: Try using the remote start function.
If replacing the battery doesn’t solve the problem, move on to the next step.
Check the Range and Environment
Ensure you are within the specified range of the remote start system. This information is usually found in your owner’s manual.
- Move Closer to the Vehicle: Try using the remote start while standing closer to your car.
- Check for Obstructions: Ensure there are no large buildings, trees, or other vehicles blocking the signal path.
- Try a Different Location: Sometimes, simply moving a few feet can improve the signal.
Inspect the Hood Pin Switch
The hood pin switch is usually located near the hood latch.
- Locate the Hood Pin Switch: Open your hood and locate the switch. It’s typically a small plunger-type switch.
- Inspect the Switch: Check for any signs of damage or corrosion. Make sure the switch is making contact when the hood is closed.
- Clean the Switch: Use a contact cleaner to clean the switch and ensure proper contact.
- Test the Remote Start: Close the hood securely and try the remote start again.
Check the Door Ajar Sensors
The door ajar sensors are usually located on the door jambs.
- Locate the Door Ajar Sensors: Open each door and locate the sensor on the door jamb.
- Inspect the Sensors: Check for any signs of damage or corrosion. Make sure the sensors are making contact when the doors are closed.
- Clean the Sensors: Use a contact cleaner to clean the sensors and ensure proper contact.
- Ensure Doors are Fully Closed: Sometimes a door may appear closed but isn’t fully latched. Double-check that all doors are securely closed.
- Test the Remote Start: Close all doors securely and try the remote start again.
Address the Check Engine Light
If your check engine light is on, it could be preventing the remote start from working.
- Check the Error Code: Use an OBD-II scanner to read the error code that’s triggering the check engine light.
- Address the Underlying Issue: Diagnose and repair the underlying issue causing the check engine light. This might involve anything from replacing a sensor to fixing a mechanical problem.
- Clear the Error Code: After addressing the issue, clear the error code using the OBD-II scanner.
- Test the Remote Start: Once the check engine light is off, try the remote start again.
Reset the System (If Possible)
Some remote start systems have a reset procedure. Consult your owner’s manual or the manufacturer’s website for specific instructions. This might involve pressing a specific sequence of buttons on the key fob or accessing a reset button on the control module.
Check the Brake Switch
The brake switch is located near the brake pedal.
- Locate the Brake Switch: Find the switch near the brake pedal.
- Inspect the Switch: Check for loose connections or damage.
- Test the Switch: Have someone press the brake pedal while you observe the switch. Make sure it’s activating properly.
- Consult a Mechanic: If you suspect the brake switch is faulty, it’s best to have it inspected and replaced by a qualified mechanic.
Inspect Wiring and Connections (Aftermarket Systems)
If you have an aftermarket system, carefully inspect the wiring and connections.
- Locate the Control Module: Find the remote start control module, which is usually located under the dashboard.
- Inspect Wiring: Check all wiring connections for looseness, corrosion, or damage.
- Clean Connections: Use a contact cleaner to clean any corroded connections.
- Secure Connections: Ensure all connections are tight and secure.
- Test the Remote Start: After inspecting and securing the wiring, try the remote start again.
Check the Antenna
The antenna is responsible for receiving the signal from your key fob.
- Locate the Antenna: The antenna is usually a small wire or module located on the windshield or dashboard.
- Inspect the Antenna: Check for any damage or disconnections.
- Secure the Antenna: Ensure the antenna is properly connected and positioned.
- Test the Remote Start: After inspecting and securing the antenna, try the remote start again.
Reprogram the Key Fob
Sometimes, the key fob needs to be reprogrammed to the vehicle’s system.
- Consult the Owner’s Manual: Refer to your owner’s manual for specific instructions on how to reprogram the key fob. The procedure varies depending on the vehicle make and model.
- Follow the Reprogramming Steps: Carefully follow the steps outlined in the owner’s manual. This usually involves a sequence of button presses or turning the ignition key on and off.
- Test the Remote Start: After reprogramming the key fob, try the remote start again.
Consider Professional Help
If you’ve tried all of the above steps and your remote start still isn’t working, it’s time to seek professional help. A qualified mechanic or automotive electrician can diagnose the problem and perform the necessary repairs. They have specialized tools and knowledge to troubleshoot complex electrical systems.
Preventative Maintenance for Your Remote Start System
To keep your remote start system functioning reliably, consider these preventative maintenance tips.
Replace the Key Fob Battery Regularly
Don’t wait until the battery is completely dead. Replace it every year or two, or sooner if you notice a decrease in range.
Keep the Key Fob Clean and Dry
Protect your key fob from moisture and extreme temperatures. Clean it regularly with a soft, dry cloth.
Regularly Inspect Wiring and Connections (Aftermarket Systems)
If you have an aftermarket system, periodically inspect the wiring and connections for any signs of damage or corrosion.
Keep Your Vehicle Well-Maintained
Addressing any engine problems promptly can prevent the check engine light from disabling the remote start.
By following these troubleshooting steps and preventative maintenance tips, you can increase the chances of keeping your remote start system working reliably for years to come. Remember to consult your owner’s manual for specific instructions and safety precautions related to your vehicle and remote start system.
Why is my remote start not working at all?
Several reasons can prevent your remote start from functioning. The most common culprits are a dead or weak battery in the key fob, a disconnected or malfunctioning hood switch, or a system that has been disabled due to a fault code or safety feature. Additionally, some vehicles require all doors and the trunk to be securely closed and the alarm to be disarmed before remote start will function. If these basic checks don’t resolve the issue, a more in-depth diagnostic might be necessary.
To start troubleshooting, first replace the battery in your key fob with a fresh one of the correct type. Next, visually inspect the hood switch to ensure it is properly connected and functioning correctly. Check your owner’s manual to understand any specific requirements or diagnostic procedures outlined for your vehicle’s remote start system. If the problem persists, consider checking for stored fault codes using an OBD-II scanner or consulting a qualified mechanic.
How do I replace the battery in my remote start key fob?
Replacing the battery in your remote start key fob is typically a straightforward process. Start by locating the small seam or indentation on the fob casing, often on the side or back. Use a small flathead screwdriver or a specialized prying tool to carefully open the fob. Avoid applying excessive force, as this could damage the casing.
Once the fob is open, identify the battery type (e.g., CR2032, CR2025) and its orientation (+ side up). Remove the old battery and replace it with a new one of the same type, ensuring the polarity is correct. Carefully snap the fob casing back together until it clicks securely into place. Test the remote start to confirm the new battery has resolved the issue.
What is a hood switch and how can it cause remote start problems?
The hood switch is a safety mechanism designed to prevent the vehicle from starting remotely if the hood is open. This is to protect anyone working under the hood from accidental engine starts. The switch is typically located near the hood latch and is triggered when the hood is closed, completing the circuit and allowing remote start functionality.
If the hood switch is faulty, disconnected, or improperly adjusted, the remote start system will incorrectly sense that the hood is open, preventing it from activating. Visually inspect the switch for any damage or loose connections. You can also try manually pressing the switch with the hood open to see if it activates. If necessary, a multimeter can be used to test the switch for continuity when it is pressed. Replacement may be required if the switch is defective.
My remote start works sometimes, but not all the time. What could be the reason?
Intermittent remote start functionality often points to signal interference or range issues. Obstructions like buildings, trees, and other vehicles can weaken the signal between the key fob and the vehicle. Also, electronic devices operating on similar frequencies can cause interference. Battery voltage in the key fob can fluctuate and cause weak signal strength as well.
Try using the remote start in different locations, particularly in open areas with a clear line of sight to your vehicle. Ensure that the antenna of the remote start system is properly positioned and not obstructed by any metal objects. A partially depleted key fob battery can sometimes cause intermittent problems; therefore, replace it with a new one. If problems persist, the remote start receiver in the car might be the source of the issue and should be investigated.
How do I reset my remote start system?
Resetting a remote start system often depends on the specific manufacturer and model of your vehicle. Refer to your owner’s manual for the recommended reset procedure, as it may vary significantly. A common method involves disconnecting the vehicle’s battery for a brief period (e.g., 15-30 minutes) to clear the system’s memory. However, be aware that this may also reset other electronic settings in your vehicle.
Another potential reset method is to consult the remote start module’s manual directly, if available. Some aftermarket systems have a dedicated reset button or sequence that can be performed. Before attempting any reset procedure, carefully consider the potential consequences and ensure you have the necessary information to restore any lost settings. If unsure, it is advisable to consult a qualified technician.
Could the ambient temperature affect my remote start?
While not a direct cause, extreme temperatures can indirectly affect remote start functionality. Cold temperatures can weaken the key fob battery, reducing its transmitting power and range. Additionally, some vehicles have safety features that prevent remote start if the engine coolant temperature is too low or the battery voltage is insufficient due to cold weather.
Conversely, extremely hot temperatures can also strain electronic components and potentially affect the performance of the remote start system. If you experience issues with remote start during extreme weather conditions, ensure your key fob battery is fresh and consider whether the vehicle’s battery is sufficiently charged. In severe cold, block heaters or battery maintainers might assist in ensuring reliable starts.
My car alarm goes off when I use the remote start. Why?
If your car alarm activates when using the remote start, it typically indicates a security system conflict or a synchronization issue. This often happens when the remote start system and the factory alarm system are not properly integrated or are sending conflicting signals. A faulty hood switch could also falsely trigger the alarm when the remote start is initiated.
Verify that the remote start system was professionally installed and is compatible with your vehicle’s factory alarm system. You may need to consult with the installer to ensure that the systems are properly integrated and programmed. If the issue persists, disconnecting and reconnecting the vehicle’s battery may temporarily reset the alarm system, but it is essential to address the underlying cause to prevent recurring issues.