Introduction
The car’s onboard diagnostics is a self-caring mechanism that analyzes the performance of different components.
To further analyze the issue, the driver or technician can attach a hand scanner, mobile phone, or a PC application to the OBD module. This will display a diagnostic trouble code that needs to be decoded for analyzing the issue. The OBDII diagnostic trouble codes comprise five characters with an alphabet denoting the malfunctioning part (1). A second character is a number illustrating whether the code is standardized. At the same time, the other three characters represent the subpart at fault and the specific fault index. Here we have enlisted the 14 most common DTC, the reasons for occurrence, common symptoms, and remedies.
Top Diagnostic Trouble Codes
P0011
Symptoms
The common error indicated by code P0011 is the illuminated engine light. Besides, it is challenging to start the engine, and the engine does not clear the emission test. All these issues show that engine code P0011.
Causes and Solutions
The common cause of code P0011 is the issues with the engine oil. Either the engine oil is polluted, or the amount of engine oil is less than the requirement. Besides, the difference in the viscosity of the oil is also a common cause of P0011. Therefore, try changing the engine oil and if the issue persists, visit a professional mechanic.
P0014
Common Symptoms
If your vehicle has failed the emission tests, it is a sign that the camshaft position is advanced and the DTC is P0014. Similarly, a hard starting or stalling engine can also be a symptom of P0014, along with the check engine light.
Causes and Solutions
The common cause of this problem can be higher oil viscosity which can make the passages clogged. Hence, the camshaft position will become advanced. Further, a failed oil-control solenoid can also cause this error. Finally, a seized camshaft phaser can also cause this problem. Hence, you should check the viscosity of the engine oil to avoid this problem. In case of a failed oil-control solenoid, or camshaft phaser, you need to contact a professional service center to replace these parts.
P0101
Common Symptoms
There are no common symptoms of this DTC, except for the check engine light and the decreased fuel economy. The car will run smoothly without any problem in the case of this particular DTC.
Causes and Solution
The common causes of this DTC can be a dirty mass air flow sensor, clogged air filter, vacuum leaks in the gaskets, and incorrect valve timing. In addition, a dirty throttle body can also cause the OBD to send a P0101 DTC causing problems in the engine performance. To resolve P0101 DTC, you are recommended to clear the mass air flow sensor and replace the clogged air filter. If the issue persists, then there is a possibility that the problem is due to a dirty throttle body or vacuum leaks that need professional services to be resolved.
P0102
It helps the ECU calculate essential statistics such as the air’s volume and density, allowing the power train control module to supply the optimum fuel quantity to the engine (3).
Common Symptoms
If the vehicle’s dashboard illustrates a check engine warning light, then there is a possibility that DTC is P0102. Similarly, suppose the motor is stalling, or the tailpipe is releasing black smoke from your vehicle. In that case, the DTC can also be P0102.
Causes and Solutions
The possible reasons for this DTC can be a faulty mass air flow sensor, dirt on the sensor, and wiring problems (1). The most common solution for this problem is the visual analysis of the sensor and its wiring. Suppose the sensor is clean, and the wiring seems fine. In that case, there is a possibility of failed sensor that should be replaced for good performance of the vehicle.
P0171
The engine works best when there is an optimum mixture of fuel to air. Generally, a mixture of 14.7 parts of oxygen and 1 part of the fuel is best for the optimum performance of the engine.
Common Symptoms
The most common symptom of P0171 is the check engine warning light. Similarly, lack of power and a stalling engine are common symptoms of P0171.
Causes and Solution
A faulty oxygen sensor can send wrong readings that display a check engine warning light and a P0171 DTC. However, in some cases, clogged air filters and leaks in the exhaust pipe can be some severe reasons to display this diagnostic code. For example, suppose the problem is due to a clogged air filter or a faulty sensor. In that case, it can be resolved by replacing the filters or sensors. However, if this DTC arises for another reason, then take the car to a professional service center.
P0172
Common Symptoms
You will feel no problem while driving with this issue (1). The only symptom you will get to notice is that the vehicle engine misfires while you are driving.
Causes and Solution
The reason could be a filthy mass air flow MAF sensor, some vacuum leakage, or a lack of power from the engine. To get it fixed, first of all, you should go for analyzing the reason that is causing the engine to run rich. Some external sensors can help you out with it. Next, inspect and replace all the vacuums and hoses. Check the fuel pipes for any leakage, holes, and cracks.
P0174
Common Symptoms
The typical symptom of this DTC is the check engine warning light. Another common symptom is a misfiring engine or lack of power from the engine (3). Suppose this problem is left unattended for a long time. In that case, it can damage some major engine components and result in a rough idle.
Causes and Solution
The common cause of this DTC can be a dirty mass airflow sensor sending false readings to the ECU. Similarly, leaks in the vacuum hose, gasket, and dirty fuel injectors can cause this problem. So, replacing the clogged filters and fuel injectors is recommended if this problem arises. In addition, you should take your car to a professional service center for detailed analysis.
P0128
Common Symptoms
Car overheating, low fuel economy, and check light on the panel could be some of its symptoms.
Causes and Solution
There could be several reasons to start this code, for example, damaged ECT wiring, a missing thermostat, your engine not having sufficient coolant, or the temperature thermostat not opening at the defined temperature. The most common solution is to reset the code (2). Then, check the thermostat to analyze its working.
P0150
Common Symptoms
A clear symptom of this problem could be the engine missing and fumbling while you are driving the vehicle. The visible smoke from the rare exhaust of the car could be another potential symptom, along with poor fuel economy.
Causes and Solution
Check the complete wiring for any visible damage. If there isn’t any, then go for repairing the sensor O2 at bank two or get your exhaust leakages repaired.
P0299
Common Symptoms
If your vehicle is making strange noises or the engine power has suddenly gone down, this is a symptom of this DTC. Similarly, the check engine light will turn on, and some vehicles can also go into limp mode.
Causes and Solutions
The cause of this DTC is a failed supercharger/turbocharger. Similarly, a faulty boost pressure sensor or fault in air intake can also cause this DTC. To resolve the issue, visit a professional mechanic who will analyze the working of the turbocharger/supercharger and detect the root cause of this issue.
P0300
Common Symptoms
If the engine shows the code P0300, the catalytic converter works effectively. Besides, the car would face some jerks and shakes (3). Also, the symptom of the engine code P0456 is the minimum power supplied by the engine, and little fuel odor will be spread around.
Causes and Solution
The significant causes of code P0456 are the faulted spark plugs or the damaged coils in the engine. Besides, the leakage in the vacuum pump and defective camshaft sensors can also turn the code on. Therefore, the replacement of spark plugs and wires can be a solution to this problem.
P0303
Common Symptoms
If you find it challenging to start your engine, it could be a symptom of this problem. Likewise, the engine fumbling and misfiring could be a clear symptom.
Causes and Solution
A faulty catalytic converter, burnt exhaust valves, poor compression, and issues with the fuel injector could be possible reasons for it. A simple solution for this problem is just to reset your code. If the code doesn’t come back to its proper condition, check the wiring of the cylinder connectors. If necessary, go for the replacement of spark plugs and their wires.
P0340
Common Symptoms
An open circuit can indicate a check engine light on the vehicle’s dashboard.
Causes and Solution
This DTC can appear if the camshaft position sensor is malfunctioning or the wiring of the camshaft position sensors is broken. To resolve this issue, visually inspect the wires and their connections in the circuit (3). Similarly, it is also recommended to connect a voltmeter to analyze the functioning of the camshaft position sensor. If the voltmeter shows low readings, then it is time to replace the camshaft position sensor.
P0420
Common Symptoms
Symptoms are that vehicle gets under power after getting warmed up, or you can say that it cannot exceed the speed limit of 40mph.
Causes and Solution
Catalytic converters get faulty due to some other problems in the engine. When they get inefficient, this particular code problem pops out. Several reasons can lead to it. Some of them are damaged mufflers, exhaust pipes, oil contamination, cylinder misfires, spark timing issues, and high fuel pressures. To fix this problem, try to repair the muffler and exhaust pipe leakages. If necessary, you can also go for an O2 sensor replacement and fuel injector replacement. If nothing works, then go for the replacement of catalytic converters (4).
P0430
This indicates that the catalytic converter cannot eliminate the pollutants the engine releases during combustion. This shows that harmful chemicals are released into an environment without being treated.
Common Symptoms
The primary symptom shown by the code P0430 is the less amount of power generated by the engine. Moreover, a rotten egg-like smell is released from the exhaust system, indicating that the pollutants are not adequately broken down (4).
Common Causes
The significant causes of code P0430 are the defective air and oxygen sensors. Also, the leakage in the exhaust system is the reason for code P0430. The issue in the catalytic convertors is also the reason for code P0430. So, try changing the catalytic converter and its component to resolve the issue.
P0442
Common Symptoms
There are no symptoms of P0442 DTC in driving. However, the car starts releasing more smoke, indicating the warning light.
Causes and Solution
The purge valve is operated by a solenoid allowing the fuel fumes to enter the engine. But a lousy purge solenoid or shortened circuit damaged by water can impact the performance of the evaporative emission system. A possible solution to this problem can be connecting a hand code scanner to decode the DTC. Finally, the circuit or solenoid must be replaced depending on the issue (4).
P0449
Common Symptoms
There are no such common symptoms of this error, as there is no impact on the vehicle’s drivability. But you can notice a slight decrease in your vehicle’s fuel economy and smell gasoline when the car is stopped.
Causes and Solution
A loose or damaged fuel tank cap is a common cause of this problem. Similarly, a damaged evaporative hose or damaged fuel tank can also cause the fuel to evaporate in the atmosphere. This issue can be resolved by replacing the fuel tank cap or replacing the fuel tank in case of damage to the hose or tank.
P0455
Common Symptoms
The typical sign of this code error is a sudden drop in fuel efficiency. Furthermore, gasoline’s pungent smell illustrates fuel particles’ significant leak or evaporation.
Causes and Solutions
The primary cause of this error is the cracks in the canister, which can lead to some significant leaks in the system. Furthermore, the EVAP hose can also become old and weak with time, which can cause significant leaks in the EVAP. Finally, defective valve control and loose gas cap can cause this issue (4). The first step is to see whether the gas cap is missing or loose. If this is not the issue, take the car to a professional mechanic to examine the canister and EVAP hose.
P0456
The evaporation control system in the car plays an important role, and it helps to control the fuel vapors to escape the environment. The code P0456 helps detect the leakage hole of less than 0.20 diameter.
Common Symptoms
The typical symptom of the driver with the P0456 is the litter smell of the fuel. Also, the engine light will be illuminated, indicating an error.
Causes and Solution
There are several significant reasons for the code P0456 i.e. the loosened gas cap that provides the space for the fuel to escape in the environment. Besides, a weak evaporation hose, a damaged purge volume control valve, and the old and leaking fuel tank can be the significant reason for P0456. So, check the fuel cap, and if it is correct, then take the car to a professional service center to further check the problem.
P0700
Common Symptoms
The common symptoms of this error can be erratic and rough gear shifting. In some cases, this error can prevent the car from shifting, putting the lives of the passengers and driver in danger.
Causes and Solution
Some common causes of this error are low transmission fluid, faulty wiring of the TCM, or failed TCM. The obvious solution for this error is checking and replacing the transmission fluid. But if the issue persists, take the car to a professional service center to check the TCM and wiring.