2020 Lexus RX350 Won't Start

Resolve Starting Issues for Your 2020 Lexus RX350

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Reviewed by
Andrew Hajjar
Written by RepairPal Car Genius
Updated January 14, 2025
0%
38% chance it's the
Battery
0%
27% chance it's the
Alternator
0%
20% chance it's the
Starter
0%
15% chance it's
Something else
The most common reasons a 2020 Lexus RX350 won't start are a dead battery, an alternator problem, or failed starter.
  • Battery: A weak or failing battery can result in difficulty starting the engine and electrical system malfunctions.
  • Alternator: A failing alternator can result in insufficient electrical power, leading to battery drain and electrical system malfunctions.
  • Starter: A faulty starter motor or a weak battery can prevent the engine from cranking properly, leading to starting issues.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

What steps should I take to diagnose the starting issue in my 2020 Lexus RX350?

To effectively diagnose the starting issue in your 2020 Lexus RX350, begin with a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Start by examining the battery, as a weak or dead battery is often the most common culprit behind starting problems. If the battery is functioning properly, proceed to inspect the starter motor; listen for any clicking sounds when turning the key, which may indicate a starter issue. Next, ensure that your vehicle has an adequate fuel supply, as a clogged fuel filter or malfunctioning fuel pump can prevent the engine from starting. Following this, check the ignition system components, including spark plugs and ignition coils, since faulty parts here can also lead to starting difficulties. Utilizing an OBD-II scanner to scan for error codes can provide further insights into any underlying issues. Additionally, inspect the alternator to confirm it is charging the battery correctly, as a failing alternator can lead to battery drain. Finally, ensure that all electrical connections are secure and free from corrosion, as loose or corroded connections can disrupt the starting process. By following this structured diagnostic approach, you can efficiently identify and address the root cause of the starting issue in your Lexus RX350.

What are the common problems that could cause a 2020 Lexus RX350 to not start?

When your 2020 Lexus RX350 refuses to start, it can be frustrating, but understanding the common problems can help you troubleshoot effectively. One of the first things to check is the battery; a dead or weak battery is often the culprit, especially if the vehicle has been sitting idle or exposed to extreme weather. If the battery is in good condition, consider the starter motor, as a faulty starter can prevent the engine from turning over. Fuel delivery issues, such as a clogged fuel filter or a malfunctioning fuel pump, can also hinder starting, so ensure that fuel is reaching the engine. Additionally, inspect the ignition switch, as a malfunction here can disrupt the electrical system's engagement. Worn spark plugs may lead to ignition problems, making it difficult for the engine to start. Don't overlook the vehicle's security system, as a malfunctioning immobilizer or alarm can block the starting process. Lastly, check the alternator and starter relay; if the alternator isn't charging the battery properly or if the starter relay is faulty, these issues can also prevent your RX350 from starting. By systematically examining these components, you can identify the root cause of the starting issue and take appropriate action.

What urgent steps should I take if my 2020 Lexus RX350 won't start?

When your 2020 Lexus RX350 won't start, it's crucial to act quickly to avoid further complications or safety risks. Start by checking the battery, as a dead or corroded connection can prevent your vehicle from starting. If the battery appears fine, inspect the fuel level; running low on fuel can sometimes be the culprit. Additionally, ensure that the gear shift is in Park or Neutral, as many vehicles have safety features that inhibit starting in the wrong gear. If you have a spare key, give it a try, as the issue might stem from a malfunctioning key fob. Pay attention to any warning lights on the dashboard, as they can provide vital clues about underlying problems. Ignoring these symptoms can lead to more significant issues down the line, so it's essential to address them promptly. If all else fails, don't hesitate to reach out to roadside assistance or a professional mechanic for help. Taking these urgent steps can help you diagnose the problem effectively and ensure your vehicle is safe to drive.

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2020 Lexus RX350 Won't Start? Causes & Solutions | RepairPal