Most common reasons for check engine light in Toyota cars indicated about something went wrong in to the engine, sensors signal to the onboard system to inform the driver via engine check light. These listed Check engine sensor faults not only occur to Toyota but to all vehicles.
How to Fix:
Map sensor usually be fix by using carburetor cleaner to clean the map sensor, but better to replace it.
Map Sensors usually installed in the fuel injector technology engines in which the Map function is to provide constant air pressure to the main system (ECU) and ECU then uses the data of map sensor and to determine and calculate the exact airflow pressure an engine require to get the optimum best combustion.
O2 sensor measure the amount of concentration level of oxygen in the exhaust gas and in the air, Rich mixture demand more oxygen this would cause a buildup of volt due to transportation ions and lean mixture demand less oxygen this would cause to low down the volt. O2 provide real time data to ECU to determine and measure the exact amount of O2 in the gas to be able to perform efficiently.
How to Fix:
Replacement is the only option.
Catalytic converter made from number of combination (platinum, palladium and rhodium), catalytic job is to filter all gasses coming from the engine into exhaust pipe before kicking out from the exhaust pipe, and this gadget is to reduce emission gas in order to save the environment from harmful gases. Catalytic converters also work hand-in-hand with a control system. This control system controls the fuel injection system and monitors the emissions leaving the engine before they enter the catalytic converter. It also contains an oxygen sensor, which detects how much oxygen is entering the exhaust system.
How to Fix:
Replacement required
Knocking sensor sense unusual vibration/pulsation caused by ignition and detonation in the engine, any abnormality detect by knocking sensor passed to the PCM System.
How to Fix:
Knocking sensor fault arises by many reason it could be low quality fuel used, sparking plug issue and knocking sensor itself have fault. Therefore better to consult a good mechanic.
How to Fix:
Coolant temperature sensor fault can be arises by thermostat wall been blocked or sensor itself. In both cases replacement needed.
Coolant temperature sensor measuring the engine temperature from thermostats wall and coolant water and then passed to the ECU, ECU then adjust the fuel calculation and engine timing to its optimal level. A hot engine requires less fuel and cold engine requires more fuel.
ABS or called wheel sensor monitor the speed of the wheel and send this information to the main ABS module system, Abs control unit uses the data as sent to prevent the brakes from locking in case of emergency stop.
How to Fix:
Cleaning of wheel sensors could remove the sensor fault.
It is located on the butterfly spindle to monitor the throttle position, in addition TP is attached to the main car ECU system, any problem in the TP would affects the car performance entirely.
How to Fix:
Calibration required
Specific Sensor issues in Toyota Brands:
