The post processing fault light is on, how to detect whether the circuit is correct?

On the dashboard of a commercial vehicle, there are two common fault indicators: sys and lights usually refer to engine fault indicators; MIL usually points to the post-processing system, once it is lit, it means that there is a problem with the related post-processing system, so what to do? First of all, let's take a look at the activation and extinguishing rules of the post-processing fault lamp and the clearing of the fault code.

1. Fault lamp activation rules:

mil lights up immediately;

MIL 3rd Driving Cycle (DC) is on.

Second, the fault lamp extinguishing rules:

1. After 3 consecutive DC or 24 engine running hours, it will be extinguished.

2. When the fault indicator is activated due to the lack of reactant in the post-treatment system, the fault indicator will immediately return to the state before activation after the reactant storage tank is full.

3. Clearance of fault codes

1. Non-deletable**: Cleared after 40 consecutive warm-up cycles (WUC) or 100 engine operating hours;

2. Non-deletable**: Clear after 9600 engine hours.

Noun term: dc: driving cycle.

The complete process of ignition, operation (if the vehicle is faulty, it should be detected), and the shutdown is called a driving cycle;

WUC: Warm-up cycle.

A driving cycle in which the engine coolant temperature rises by at least 22 degrees and reaches at least 70 degrees is considered a warm-up cycle.

It is recommended to turn off the current first, and then open the equipment box for inspection.

The CAN bus fault refers to the poor contact of the CAN interface of the ECU.

2.Excessive dirt and carbon deposits, abnormal air circulation, and inability to accurately control the normal air intake volume, resulting in unstable gas levels and making the engine not work well.

3.The low fuel pressure combined with the poor constant pressure performance leads to a low level of atomization in the system, making it difficult for the car to start.

Extended Materials. About the car dashboard.

1.The car dashboard is a device that reflects the working conditions of each system of the vehicle. Different cars have different gauges. However, the conventional instruments of a one-button car include a speedometer, a tachometer, an oil pressure gauge, a water temperature gauge, a fuel gauge, a charging gauge, and so on.

2.Hyundai automobiles have made a variety of indicators or warning lights under the instrument panel, such as coolant draft liquid level warning light, fuel level indicator, washer liquid level indicator, charging indicator, high and low beam dimming indicator, transmission gear indicator, brake anti-lock braking system (ABS) indicator, drive force control indicator, airbag (SRS) warning light, etc.

Hope it helps, hope!

It can check for faults, and the fault codes can be divided into current faults and historical faults. You can read the historical faults directly with the decoder.

The engine fault light is still on when the car is playing, and the fault code can be eliminated with a decoder, and the first time the leakage of the emotion that no longer appears indicates that it is the sensitivity of the car computer that causes the first chang, and the car computer is very sensitive, and sometimes there will be a misjudgment and the fault light will be lit! If it recurs soon after elimination, then it is necessary to check the specific fault according to the condition of the car!

In fact, if you don't know that the circuit ** is damaged, you can go to the mall to buy a multimeter for testing. It is understood that whether it is the triode of the electronic circuit or the resistance value of the line.

Direct ObservationWhen there is a problem with the circuit in your home, you can use the direct observation method if you do not have a multimeter. In general, you just need to look at the circuit with your eyes** to see if there is an abnormality.

In fact, the comparison method is also a very effective method to eliminate the fault part of the circuit. This method mainly compares a circuit that is in normal working condition with a circuit that seems to be faulty.

Signal tracing methodIf the circuit is particularly complex, the signal can be terminated at the input.

Hello friends, the detection methods related to the fault light of the car are as follows. The first is that there is a fault in the vehicle engine system, which is necessary to use the computer to read the dissipation obstacle**, and do the relevant diagnosis and analysis according to the fault**. The second situation is the failure of the emission system, which requires a slow cleaning of the carbon deposits inside the engine and the three-way catalytic converter.

In the third case, if this is an occasional failure, you can start the vehicle back and forth to operate 3 to 5 times, and it will generally automatically clear or break the negative pole of the battery line.

The home circuit is generally composed of the entrance line, the main switch distribution box (here mainly refers to the air switch, power-off protector, etc.), socket switch, electrical appliances and other parts.

It is important to remind everyone that all inspections are to be carried outCut off the power supplypost.

The first is the air switch. Check that the air switch box is clean and free of debris, the switch can be opened and closed smoothly, and the material of the switch box has a high temperature resistance level; Whether the circuit identification of each switch control is clear, check whether each line is unblocked and whether the identification is correct according to the identification; Use the universal meter to test the switch in the open and closed state, and measure whether the voltage is normal, you can find a professional electrician to operate to ensure that the voltage is within a safe range; Check in detail that the wire joints in the box are firm and the wires are placed in an orderly manner.

The second is the inspection of the wires. Circuit inspection is mainly divided into exposed and hidden lines. The exposed wire can be observed after the power is off, whether the wire insulation layer is discolored, cracked, etc., and the wire is stiff when bending the insulated wire with both hands, and even the insulation layer is cracked, and the insulation layer falls off, which indicates that the wire has appeared in different degrees of aging and serious aging.

We need to connect each line separately to observe whether the connected electrical appliances are energized normally and whether the voltage is stable. Generally speaking, regular factory wires will be marked with the expiration date. If it is too old, it is recommended to replace it with a new one.

Then it's time to check the switches. Open them one by one, observe whether the bulbs are lit normally, if not, check the order from the bulb to the switch to the line one by one; If you encounter a light bulb flickering, do not ignore it, and check whether there is any poor contact or short circuit.

Finally, there is the socket checkFirst, observe whether the socket shell is in good condition, knock it with a screwdriver to see if it is loose, open the switch box with a screwdriver to check whether the interface is firm, ensure that the line is not aging, and finally plug in the power tester to judge the power on of each socket according to the identification.

Hope it helps!

If the instrument indicator is not lit, first check the power supply fuse of the dashboard, and replace it if it is blown. Disassemble the dashboard, the lights are generally at the back of the dashboard, replace the lights that are not lit, and generally the individual lights are not lit to indicate that there is no problem with the fuse and wire, the main reasons are as follows

1. The light of the dashboard is damaged, and the light needs to be replaced in time;

2. If the power supply line of the dashboard is broken, there is an open circuit or short circuit, which will also cause the car dashboard to not light up;

3. If the power supply fuse of the car dashboard is broken, there will naturally be no power supply, and the dashboard will not light up.

Precautions in the use of the car dashboard:

1. When the indicator light is on, the odometer should be observed immediately, if the cumulative mileage reaches or exceeds l00,000km, the timing toothed belt must be replaced, otherwise the timing toothed belt may break, so that the engine can not work normally.

2. After replacing the new timing toothed belt, it is necessary to open the rubber plug outside the reset switch on the mileage dial, and press the reset switch inside with a small round rod to extinguish the timing toothed belt indicator.

3. After replacing the new timing toothed belt, remove the odometer and adjust all the readings on the odometer to the 0 position.

The engine fault light is on, but it does not affect normal driving, and there are three reasons, first: the vehicle exhaust emissions are not up to standard, mainly caused by excessive carbon deposits. Of course, the failure of the three-way catalytic converter and the blockage of the fuel injector will also cause the engine fault lamp to be always on, and the main reason for these fault lights is related to the oil quality, in addition to whether the gasoline is fully combusted, so when we refuel the car, we should refuel in accordance with the gasoline standards stipulated by the manufacturer, and 95 gasoline will never be added to 95 gasoline, and in order to reduce the occurrence of the above fault lights, we should also standardize our driving behavior in the ordinary driving process, and there can be no sudden braking. Non-standard driving habits such as stepping on floor oil.

Clause. Second, the engine fault light may also be caused by the failure of the internal parts of the engine system. Riders who understand the internal structure of the engine know that the engine system is assembled by a lot of sensors and various small parts, which need to be maintained during ordinary driving, and with the accumulation of time, these parts and sensors are easy to fail, so if this happens, it is recommended to go to the 4S shop for maintenance, and like pulling out the key to restart the vehicle to solve the problem of the fault light on, this method is unreliable and not practical.

Clause. 3. The cause of the bright spot of the engine failure light may also be caused by the failure of the transmission system. The internal structure of the gearbox is also more troublesome, and it requires a high technical process to manufacture, like the domestic independent brand car is difficult to develop its own gearbox. Worn internal parts of the gearbox, error messages from ABS failures, etc., can make the engine fault light on.

But many cars nowadays have a separate engine fault light from a transmission fault light.

It is possible that the exhaust emissions are not up to standard, and there is a problem with the three-way catalysis.