5 Possible Causes of Lexus Push Button Start Problem

The push-start button has been a welcome development in the automotive world. It allows the drivers to conveniently start their Lexus with a button and turn on necessary functions.

However, it is not without its problems. Many Lexus owners have reported issues with their push-start button, including refusal to work.

Several factors could cause the push-start button to fail, some of which will be examined in this article. Also, we shall explore remedies to get your Lexus push-start button working again.

How does the Lexus Push Button Start Work?

The Lexus Push Button start works with the help of a key fob. Once the key fob is in the car, it broadcasts signals to its computer system. Once the computer system receives the signals, it recognizes them and allows the car to be cranked. 

Furthermore, to start the vehicle, ensure the key fob is inside the Lexus and the gear is shifted to park. Go ahead to press and hold the brake pedal, then push the start/stop button until the engine starts.

Causes of Lexus Push-Button Problem

When you encounter a problem with your Lexus push button, it ultimately deters you from operating the vehicle. Knowing the possible causes of this problem is essential to fix it properly. 

Here are some possible causes of a Lexus Push button problem.

1. Faulty starter relay

The starter relay is a circuit completer between the battery and the motor. It steps up the battery current; when this happens, less current is required during the ignition process. 

The motor will not receive adequate electrical current when the starter relay is bad. It is why when you push the start button, your vehicle struggles to start or does not start at all. 

In addition, the starter relay can be found under your vehicle’s hood, inside the large box, or fuse box.  

2. Faulty battery and related cables:

Your vehicle’s battery is vital to igniting and ensures the push-start button works. Once the push button is pressed, the battery releases an electrical current to the starter relay. 

Sometimes, you may have a weak or faulty battery that does not allow ignition. No matter how long or long you press the push start button, your car may not start with a weak or dead battery. 

Also, the battery may be fine in other cases, but its associated cable might be faulty. It creates a disconnect or does not allow an electric current to flow, which will require the push start button to work.  

3. Wiring connection problem 

All electronic components in the car use wiring connections, and the push start button is no exception. The wiring connection supplies electrical current to the ignition system. Other wiring connections could connect the ignition system and the ECM. 

After prolonged use, the wire could get corroded or damaged by other factors like pests, water, etc. When this happens, the electrical power is cut off, and the push-start button does not work. 

Also, when a wire is damaged, communication between the ignition system and the Engine Control Module (ECM) may be cut off. It makes ignition more difficult because the engine controls the ignition system.  

4. Failing ECM

The ECM is the brain behind the proper functioning of your vehicle. It controls a large area of the ignition system. It contains fuel injection and the spark’s ignition timing, among many other things. 

Furthermore, when the ECM begins to fail, so does the whole ignition system. You will not get proper ignition when you press the push start button. The various components’ timing is inaccurate because of the failed ECM. 

5. Faulty starter key fob 

Your push button start will not work if the starter key fob is not working. Once in the key, the starter key fob is meant to transmit a signal received by the vehicle receiver. 

The key fob problem is usually due to a low battery. All you need to do is replace the battery in the key fob, and you are good to go. 

How to Fix A Lexus Push-Button Problem?

With the proper understanding of some of the causes of the push-start button problem, we can proceed to how they are fixed.

Below is how you can fix a Lexus push button start problem. 

1. Fix faulty relay

Firstly, you need to find out if the relay is faulty. The starter relay is located in the fuse box located under the hood of your Lexus. You can use your vehicle’s manual if you can still find it. 

Use a flat screwdriver to check the relay cover; if you do not observe any fault, go on to the next step. Have a friend start the car for you. It is still good if you hear a clicking sound from the relay. If not, have it replaced immediately!

2. Charge or replace the battery. 

There are many ways to know if the problem is a battery issue. If you are having a problem with most of the electrical components in your vehicle, it could be a battery issue. 

You could borrow a friend’s battery and try to start your car with it; if it starts, you have a battery issue. 

To solve this problem, you will have to have the battery charged. If, after charging the battery, the problem continues, your battery may have failed. Get yourself a new battery. 

3. Fix wiring problems.

The good thing is that your vehicle’s manual gives a well-detailed diagram of the wiring connections in your car. You can easily find the wiring connection associated with the push button using the manual. 

Once you can find the wires associated with the push button, examine them. Observe any form of damage like corrosion, disconnection, and more. Once you can find these damages, replace the wires entirely. 

4. Fix the ECM problem. 

Regarding ECM issues, the two major causes of its failure are software problems and damaged modules. If you have a software problem, you must get your ECM reprogrammed. 

Reprogramming your ECM is not easy work and requires expensive professional tools. The tools make the process easier because it is entirely automated. Unless you have this tool, you may need professional help. 

On the other hand, if the ECM module is completely damaged, you may need a complete replacement. You will have to find a computer module compatible with your vehicle.   

Final Thoughts!

Without the push button start feature makes starting your Lexus very easy. However, if you have a problem with the feature and cannot get your car to start, know that Lexus has made an alternative option for you. You can use the smart key option; this allows you to get into your vehicle if the key fob is not working. You can also start the car by placing the smart key next to your start button and pressing the button for a while.

  • Edmond Davis

    I'm Edmond Davis, an automotive expert with years of experience in vehicle repair, performance, and safety. I graduated from the University of Michigan with a degree in Automotive Engineering and have worked with major companies like Ford, GM, and Chrysler. I'm a trusted source of information for anyone looking to learn more about cars or improve their driving experience.

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