Lexus Diagnostic Codes Explained

If you own a Lexus, then you know that it is important to keep up with the required maintenance. Not only will this help your car run smoothly, but it will also help maintain its value. When your Lexus presents a check engine light, the team at A+ Japanese Auto Repair is here to investigate your service codes and maintain and repair your Lexus. 

Nowadays, many car enthusiasts purchase diagnostic tools for their home garage, as a means of understanding where their car is in crisis. As diagnostic tools become cheaper, we are beginning to encounter more Lexus owners who have already performed the computer diagnostic, but have the instincts to still bring their Lexus in to A+ Japanese for their repairs. Our customers know that it's important to understand not only what those codes mean, but the problems that can be associated with those repair codes, before working on your Lexus.

Repair codes are divided into four main categories: the Powertrain, the Body, the Chassis, and Network Communications. In cases where the second digit is a 1, those codes are enhanced or specific. In cases where the second digit is a 0, those problems are generic or global in nature. 

Here are the most common repair codes associated with a Lexus:

P0010: "A" Camshaft Position Actuator Circuit - The P0010 code means that there is an issue with the camshaft position actuator. This can be caused by a few different things, including a dirty or faulty variable valve timing oil control solenoid, a broken timing chain, or stretched timing chains.

Codes P0171 – P0175 deal with sensing your oxygen levels:

P0171: This code tells you that your system is too lean (your engine is getting too little air or too much air).

P0172: This code means that your system is rich, indicating that there is too much gasoline and not enough oxygen in the engine.

P0173: This code gets triggered by the engine control module when it senses that the air to fuel ratio is imbalanced and the engine control model is overcompensating.

P0174: This code tells you that your Mass Air Flow Sensor is under-reporting the air coming into the engine.

P0175: This code means that your system is rich (too much gasoline, not enough oxygen).

Codes P0300 – P0305 deal with engine misfires:

P0300: This code is triggered when multiple cylinders misfire.

Codes P0301 - P0305: These codes indicate an engine misfire in cylinder 1 through 5, with the last number being the cylinder in question.

Codes P0411 - P0455 deal with the evaporative system

P0411: This code will appear when you have a problem when the secondary injection system has an incorrect flow detected.

P0440: This code will appear when there is a leak in the fuel tank vapor system or a vapor pressure sensor malfunction.

P0442: This code means that there is a problem with the evaporative emission control system. This code typically appears in tandem with other evaporation system codes.

P0446: This means that the evaporative emission control system vent circuit is malfunctioning.

P0455: This code means that there is a leak in the emission control system. A good place to check first is the gas cap. Another common explanation for this leak is a bad vent control valve.

P0401: the exhaust gas recirculation system flow is insufficient.

Codes P0420 & P0430 deal with the catalytic converter

P0420: the catalytic converter is not functioning at max efficiency

P0430: This code is more general, it indicates that there is a problem in the catalyst system. Since this code is very general, it is typically also seen with misfire codes and oxygen sensor codes.

Understanding the repair codes for your Lexus can help you prepare for the work ahead, but always remember the car itself has something to day outside of the diagnostic system. So if you want our qualified team to delve into the mystery, schedule an appointment today at A+ Japanese Auto Repair. We are conveniently located at 780 Industrial Road, San Carlos, CA 94070. And don’t forget to Like us on Facebook for news, updates, and specials!