Why is my remote start not working?
Most often a dead key fob battery, a weak 12-volt battery, or a safety/immobilizer setting is preventing the remote start from engaging.
When a remote-start system won’t engage, it can be caused by a mix of power issues, security protections, or compatibility problems. This guide explains the most common causes and provides practical steps to diagnose and fix the issue for factory-installed, dealership-enabled, or aftermarket remote-start systems.
Common causes
The following items cover the most frequent reasons remote start fails. Addressing these in order often resolves the problem without specialized tools.
- Dead or weak key fob battery, which prevents the vehicle from recognizing the remote start command.
- Weak or discharged 12-volt vehicle battery, which cannot supply the surge needed to start the engine.
If none of these factors explains the failure, the issue may be more complex and tied to vehicle-specific systems or a defective module.
Troubleshooting steps
Use these steps in order to systematically identify and fix the root cause of a non-working remote start.
- Check the key fob battery and try a spare remote. If the spare works but the primary does not, replace the battery or reprogram the fob as needed.
- Test the vehicle’s 12-volt battery. If the battery is under load or reads low voltage, replace or recharge it and re-test the remote start.
- Ensure the vehicle is completely in Park (automatic) or in a safe neutral position (manual may be restricted). Engage the parking brake if required by your model.
- Verify hood is fully closed and the hood latch is functioning. If the hood sensor is false-triggering, have the latch inspected.
- Check the immobilizer/key recognition. If the dash shows immobilizer warnings or the key isn’t recognized, re-sync the key or try a spare key per the manufacturer’s procedure.
- Inspect aftermarket remote-start components (if installed). Confirm correct wiring, proper integration with the ignition and tach signals, and that the module is up to date with your vehicle’s software.
- Test for signal range and potential interference. Move within a clear line of sight to the vehicle and retry; note whether closer proximity resolves the issue but farther range does not.
- Review any OEM app or vehicle settings governing remote start. Ensure the feature is enabled, the vehicle is locked when starting remotely (if required by the system), and that app permissions or subscriptions are up to date.
- Consult the vehicle’s service or owner's manual for model-specific restrictions (such as manual-transmission limitations or special start sequences) and consider a professional diagnostic if problems persist.
If the problem remains unresolved after these steps, you should consult the dealership or a qualified installer to perform a deeper check, including module diagnostics and wiring inspections.
Model-specific considerations
OEM vs aftermarket remote-start modules
Factory-installed remote start is integrated with your car’s safety and immobilizer systems, but aftermarket modules require precise installation and calibration. A misconfigured installation can trigger immobilizer conflicts or engine start failures, and it may affect warranty coverage. When in doubt, seek a certified installer or your dealer’s service department.
Manual transmissions and push-button starts
Many remote-start systems either do not support manual transmissions or require a special override. Push-button start vehicles also vary in how the remote-start sequence is initiated. Check your owner’s manual or the specific remote-start kit documentation for the correct procedure and any model-specific restrictions.
Vehicle apps and connected services
Some remote-start capabilities rely on an accompanying app or connected service. Ensure your subscription is active, the app is updated, and the car is connected to the provider’s network. Updates or outages can temporarily disable remote-start functionality.
Summary
Remote start issues most often come down to a weak battery (fob or vehicle), safety interlocks (hood, Park position), or immobilizer/key recognition problems. Begin with the basics—fob and battery checks, vehicle battery health, and ensuring the car is in the correct state for starting—then move through wiring and configuration checks, especially if aftermarket equipment is involved. When basic checks don’t resolve the problem, a professional diagnostic can identify ECU conflicts, sensor faults, or installation errors that require specialized tools and expertise.
