In injection engines, in the event of a malfunction in the electronic engine management system, the Check warning lamp on the instrument panel lights up. The ECU controls the engine using a sensor system. Typically, the Check warning light comes on when one of the sensors fails.
The crankshaft position sensor is designed to calculate the speed of rotation of the engine crankshaft, determine its position and, accordingly, the pistons in the cylinders. This sensor is based on the principle of electromagnetic induction. If this sensor does not work correctly, the engine starts to run unstably at idle. If the crankshaft position sensor fails, the engine stalls and does not start at all. The phase sensor is designed to determine the valve timing for each cylinder of the engine by the controller. The principle of operation is based on the Hall effect. The sensor is located on the head of the block, in front of it from the side of the intake manifold. If this sensor fails, the ECU switches from phased injection to twin-parallel (standby), which leads to erratic engine start and increased fuel consumption. The throttle position sensor detects the opening of the throttle valve. If this sensor malfunctions, the engine begins to emit a characteristic knock, especially with a sharp drop in speed in the acceleration mode, and fuel economy and power also decrease due to constant engine operation at low ignition timing angles. (up to 1500-3000 rpm.), when the gas pedal is released, the speed decreases slowly or does not decrease at all, and only overgassing helps to reduce them. Also, jerking is observed when the vehicle accelerates. The MAP sensor reacts to changes in the absolute pressure in the intake tract. A malfunction of this sensor leads to the engine running on too lean or too rich mixture, unpleasant exhaust, misfire at idle and under load, problems when the engine is muffled. The knock sensor is designed to detect characteristic knocking sounds in various operating modes. In the event of a sensor malfunction, the engine begins to detonate, especially with a sharp drop in speed in acceleration mode. Also, fuel economy and engine power decrease in conditions of constant operation with low ignition timing. The coolant temperature sensor is designed to assess the thermal state of the engine. If this sensor fails, the ECU switches to standby mode: the fan is turned on, increased idle speed is set, the engine temperature is determined by its operation time. In case of complete failure of the sensor, it becomes difficult to start the engine and an increased fuel consumption is observed. The speed sensor is designed to determine the speed of the car. If this sensor does not work correctly, the engine runs unstable, when the load is suddenly dropped, the engine stalls, the dynamics deteriorates, the electronic speedometer and the trip computer give incorrect speed readings. The oxygen sensor estimates the amount of oxygen contained in the exhaust gases. If it malfunctions, there are periodic fluctuations in idle speed, increased fuel consumption. In addition, a lit Check warning lamp may indicate an open circuit, short circuit, break (slip) of the timing belt, moisture, overheating and other malfunctions. The error code, which is determined by the scanner in a matter of minutes, helps to more accurately determine the malfunction.
