Keyless systems in cars make the engine starting process completely automatic. With any automatic system comes the possibility of malfunctioning.
As such, you might face a potential keyless start system problem.
The most frequent problem with these systems is failing to start. Faulty key fob batteries or defective receivers are common reasons behind this issue. But you can easily replace batteries or check up on the receivers to fix it.
However, there are some keyless start issues that require discrete solutions. Knowing the basics of the system will help you deal with it easily.
In this article, we’re going to address all the possible issues and provide the proper solutions.
How Does a Keyless Start System Work?

To get a better understanding of the types of problems that can occur, you should know how the entire keyless start system works.
The procedure starts when you press the start button on your fob. It sends a unique radio signal to the car’s system, which is then picked up and validated.
If the accurate signal has been sent, it activates the push button to allow you to start the car engine with just a press.
Security measures of such a system are very high because the signal your remote sends is completely unique and can only be picked up by your specific car.
The Types, Causes, and Solutions to Keyless Start System Problems
We are going to start off by addressing the most commonly caused problems, breaking down each of their causes, and providing the most extensive solutions.
So, hopefully, you’ll find everything you came here looking for.
Type 1: System Failure

This is by far the most commonly faced problem of the keyless start system. A system failure occurs when your car does not respond to the remote’s commands and refuses to start when you press the ‘ENGINE START/STOP’ button.
Additionally, on some models, an error message might pop up on the screen saying, ‘Keyless Start System Problem.’
Facing such an issue is very bothersome as you literally cannot use your vehicle, so looking for a solution right away is necessary.
Reason 1: Inefficient Brake Pedal Force
With a keyless start system, to start the engine using the push button, you need to press the brake pedal. So, having problems with your brake pedal might be directly connected to the system failure.
Solution
Make sure you’re putting enough pressure on the brake pedal while pressing the button. If that doesn’t work, you can try to tighten the cables of the brakes using an Allen key.
If it still does not work, there’s not much you can do other than consult with a technician.
Reason 2: Dead Starter

It’s not uncommon to see faulty starters in cars as they can gradually break down over use. To know if it’s an issue with your starter or not, you should try to crank up the engine directly using another car’s battery (jump-starting).
Solution
Unfortunately, if you are faced with a dead starter, you’ll have to go through a lot of trouble to get it fixed by yourself.
Initially, you will need to get into the keyless system box and then gradually inspect every component to figure out which one is faulty.
The ignition switch is typically known to wear out fast. Once you’ve determined the defective part, you will need to replace it.
Reason 3: Dead Car Battery

We’ve talked about dead fob batteries, but your car’s keyless start system also uses batteries to receive and validate the signal.
Solution
In most cases, the battery just runs out of energy, so all it requires is a replacement.
The battery is normally located under the hood, but if you can’t find yours, look in your vehicle’s handbook.
To figure out whether the battery is the issue, grab a voltmeter and check the voltage of the battery. If it is lower than 12V, you will need to replace it.
A battery sits at 1-0.8V when it’s defected or completely used up.
Type 2: Dysfunctional Key Fob
If your car is not responding to the button presses on your key fob, there’s a high chance that the problem is with the remote itself and not the vehicle.
Reason 1: Dead Key Fob Battery

Your remote key uses batteries to operate and send radio signals to your car. So, naturally, the batteries may run out or become defective over time.
Solution
The most straightforward solution is to replace the batteries. Most key fobs use a CR2023 battery. But some might also use CR2450, CR2016, CR1616, and CR2025.
Just remove the back panel of the remote (use a screwdriver if required), take out the old batteries, and put in the new ones.
Before worrying about other possible causes, check the batteries, as it is the most common issue regarding the system.
Reason 2: Broken Key Fob
As we have become quite used to dealing roughly with keys, damaging your key fob is highly probable. Breaking the key fob puts you in a pinch as you cannot start the engine.
You can get inside the car with the key. But since most vehicles with keyless systems don’t have an option to start the engine with the key, you’re stuck.
Solution
Depending on how much the remote is damaged, you may or may not be able to fix it yourself. Since every remote sends out a unique signal, the internal circuitry is quite sensitive.
If it is something as simple as a misplaced battery, you can open it up and put it back in place.
However, if the internals has been damaged, the possibility of getting them fixed is pretty low. In that case, contacting a technician or a car dealer is your best choice.
Type 3: Faulty Signal Receiver
The radio signal transmitted by your key fob is received by a radio receiver on the car. If it is not functioning properly, the car engine will not start.
Reason 1: Malfunctioning Antenna
A signal receiver exists in the form of an antenna in a vehicle. If it gets broken, bent, or somehow covered in dirt, it might not be able to catch the signals of the fob.
Solution
Look for the signal receiver on your car. It is most commonly found above the rear hatch. You can also look below the rear cargo area floor cover or behind the trim panel.
Once you’ve located it, examine it for potential damages. If it has been covered in dirt, clean it off. If it has been severely bent or broken, you will need to replace it.
Reason 2: Damaged Wires
Since the antenna is normally placed far away from the keyless start system box, jumper wires are used to connect the antenna to the circuit board.
For various reasons, these wires may wear out over time, which can disrupt the signal received by the antenna and prevent it from reaching the circuit board.
Solution
If you have long enough wires at your disposal, you can try to connect the antenna directly to the circuit board using those wires and check if it gets a signal.
If it does, then the previous wires were faulty, and you’ll need to replace them.
Type 3: Blown Out Fuse
Every keyless start system has a fuse attached between the wires that connect the circuit board to the battery. The fuse prevents any potential damage done to the circuit board from excessive voltage or current.
The fuse blows out and creates a gap in the circuit that prevents electricity from passing through, so naturally, when a fuse is blown, the system stops working.
Reason 1: Faulty Car Battery
The system gets power directly from the car battery. So, any excessive current or voltage will originate from the battery itself. 12V DC is the standard for all car batteries, though the current might vary.
Solution
Take out the car battery from under the hood and hook it up to a multimeter. First, check the voltage readings, and then check the ampere readings.
The voltage should not be above 12V, and for the amps, check the label of the battery and match it with your reading. For better assurance, check your vehicle’s handbook and match the results.
If they go above the suggested metrics, you should consider a battery replacement.
Reason 2: Short-Circuit
It’s not uncommon to see people spilling water over their car, which can potentially cause the internal connections to short-circuit. When a circuit is shorted, it triggers the fuse.
Solution
If only the fuse has been blown out, then just replacing the fuse will get the job done. Make sure to get one that meets the requirement of the system.
Frequently Asked Questions
- Is a keyless start system problem dangerous?
A problem in your keyless start system can be potentially dangerous if not fixed right away. Since a dead battery is the most common cause behind it, if you don’t replace the batteries soon, the battery may degrade and damage the surrounding circuits.
- Can I manually start a keyless car?
It strictly depends on the vehicle model whether you can or cannot manually start a keyless car. Some key fobs have a backup system that allows the remote to work even with a dead battery. If that’s the case, you just need to bring the remote inside your car and press the engine start button, and it should fire up.
Final Words
Regularly checking up on the components and especially the batteries of both your key fob and your car will save you from a lot of hassle at the most unexpected times.
Getting locked out of your own car is definitely an experience you would want to skip. But even if that ever happens, you know the solution to almost every keyless start system problem. We hope we’ve been helpful.
Meta
Checking up on the batteries is the most basic solution to a keyless start system problem. Learn to tackle every problem regarding a keyless system from here.
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