Diagnosis of engine management systems

The main objective of the injection is a workflow management engine. It is for this part of the system management controller includes COURT (engine management), actuators and sensors. On the sensor signals the controller can determine the right amount of fuel and time when it is necessary to feed the cylinder, it also determines the time for the spark. Child delivery mechanism is a cylinder fuel mixture in the required proportion and form a spark. In addition, there is another important task that the Court shall decide. It then goes about diagnosing engine management system, or rather self-diagnosis. What is an "on-board diagnostics? The notion of on-board diagnostics to understand the system software and hardware (sensors, controller COURT, actuators), which can identify and determine the fault system of the engine, and the reasons why they might arise. Which require on-board diagnostics? Onboard diagnostics designed to solve the following problem: 1.Identifikatsiya and identification of errors in the OVC and the engine itself, which can lead to: to exceed the maximum exhaust emission car. Such a requirement for diagnosis applies to all, without exception, the engine management system to ensure compliance with emission standards Euro-2 "; to the deterioration of engine parameters (for example, reducing torque and engine power, poor driving characteristics, increased fuel consumption); the failure of the control system components or the engine. For example, damage to the catalytic converter, when there are omissions of ignition. 2.Informiruet driver of faults through the inclusion of special lights on the dashboard. Burning light bulb does not force the driver to immediately stop the movement and stop the vehicle. It's just about that side car system has fixed the engine control system malfunction, and the movement of the vehicle can be continued in emergency mode. In this situation, the driver must soon deliver the car to the service station. If the diagnostic light is flashing - this means that the fault detection can lead to irreversible consequences, and in some cases cause damage to the other parts. For example, the detected gaps inflammation can provoke a breakdown of the catalytic converter. 3.Sohranyaet information found fault. At that moment, when the system spotted a breakdown in the computer's memory will be entered the following information: according to international classification error code attributes (or status flags), which characterize the state of malfunction in a time when information is read by another diagnostic tool, the stop frame (in other words - Freeze Frame) - values ??are very important for the system parameters at the time of fixing errors (found in controllers M7.9.7i MR7.0). Error codes, and all information which is recorded along with them very easy job of finding and repairing damage the engine management system. 4.Aktivizirovanie emergency mode the engine management system. When a fault is detected, in order to provide acceptable driving performance of the machine to prevent the failure of other important systems of the car, in order not to allow the escape of toxicity values ??for the threshold, the engine management will be forced to switch to emergency work. The essence of the emergency mode is that when there is proper functioning chain of a sensor, controller COURT is used to replace all the calculations, which are stored in computer memory instead of a real signal. In emergency mode, the car can reach customer service. It happens that the car owner does not know that car is in emergency mode. 5.Vzaimodeystvie with equipment diagnostics. The fact that the automobile is a system fault signal lamp. Then, the system board diagnostics allows read diagnostic information, which was stored on the computer. For this purpose, in the control system organized by a serial communication channel, it comprises the controller COURT connecting pigtail (K-Line) and standardized diagnostic block, in order to connect the diagnostic equipment. Communicate using standardized protocols. With the help of hardware diagnostics service team read the information about errors from your computer's memory, after which you can perform a series of verification tests, through the actuators. OBD system will become operational in the moment that turned on the ignition, finishes its work when the controller will switch to «stand by». At the time of the one or the other algorithm, and their subsequent work can be limited to certain regimes. Incorporated into the controller diagnostic algorithms can be divided into the following groups: Diagnostic sensors COURT. Sensors system controls to cliff, "a lot", the source or the closure of the signal chain. For a number of sensors implemented test signal at the output. In this case, the controller monitors to gauge the magnitude was in acceptable range. Driver diagnostics output stages of the controller or the diagnosis of actuators COURT. Actuators are controlled at the break, the power source control circuit or a short to the "masses". Functional Diagnostics (Diagnostics subsystems OVC). In the engine management system, secrete a number of subsystems: subsystem gasoline canister; subsystem ignition fuel subsystem, the subsystem of the neutralization of exhaust gases; subsystem to maintain idle. Diagnosis of engine management system with all subsystems performs a specific task. In the sub-systems have certain requirements on the magnitude of tolerance and connection settings. Functional diagnostics will give us of the quality of the works and performance subsystems for OVC in general.