Maintenance of electronic anti-theft system

Under normal circumstances, if someone attempts to start the engine in the anti-theft state by illegal means, the anti-theft control module will take intervention measures to close the ignition circuit or fuel injector circuit of the engine and set the fault code.

1. Electronic security is the feature that you are triggered

When the car equipped with electronic anti-theft system fails to start, the first need to determine whether the electronic anti-theft system is locked, or the engine itself has a fault.If the engine starts 2.After flameout, it is necessary to consider whether the electronic anti-blue system is triggered, do not hastily remove the irrelevant parts.

A simple way to determine whether an electronic security system is locked is as follows:

(1) see if the engine is easy to start, but not easy to start.

If so, it’s not a lock.An electronic anti-theft lock is characterized by an engine that can start, but then automatically shut down after 2-10s and never start again.

(2) check whether the anti-theft indicator light on the combination instrument is on.

If the indicator light is on, the anti-theft system is dead.If the indicator light is not on, there is an oil injection signal but weak, it is not an electronic security system lock.

(3) if there is a fault code stored in the control unit of the combined instrument, it indicates that the electronic anti-theft system has been locked.

Electronic anti – theft system locked, generally need to use a fault diagnosis instrument and input a specific password, in order to solve the problem.

2. Access to anti-theft passwords

Theft-proof password is the main basis for theft-proof control module to identify whether it is a legitimate user. Its function is used to decrypt and reconfigure the key.In many cases, the “password” is simply the resistance value of the key.

There are several ways to obtain anti-theft passwords:

(1) a 14-bit identification code and a 4-digit password are posted on the anti-theft control module.

(2) look on the key card.The new car’s security code is embedded in the car’s key card, and scraping off the vinyl will reveal a four-digit security code.

(3) look in the glove compartment.Some cars have anti-theft codes pasted on the left side of the glove compartment in front of the soft seat.

(4) some cars’ anti-theft codes are included in user manuals.

(5) the anti-theft codes of some cars are affixed to the luggage cases of new cars.

(6) if the anti-theft password cannot be found in the above places, you can connect the fault diagnosis instrument and enter the “anti-theft system”. After a few seconds, the 14-bit identification code of the anti-theft control module will be displayed, and then you can inquire the anti-theft password to the service hotline (or telex) of the seller or importer.

3. Solutions to abnormal anti-theft system

(1) alarm horn often sounds.

Some cars park at the roadside and set the anti-theft status, whenever large cars or heavy vehicles through, will cause alarm horn honk, this is because of vibration sensors too sensitive cause.In the electronic anti-theft system, a vibration sensor is installed, which is used to detect the intensity of car body vibration.If its sensitivity is too high, a breeze will cause the alarm, the sensitivity can be adjusted at this time.The adjusting knob is installed on the vibration sensor or in the main engine box.The sensor of the anti-theft system can be removed, or the connector of the main body of the anti-theft device can be removed.Generally, there are adjustment holes left. When adjusting the adjustment knob installed in the host box, it is unnecessary to disassemble the host.

If the car has no obvious vibration, after a period of time alarm horn automatically sounding, this phenomenon is often due to the door did not close well, the door light switch is bad or the wiring caused by a short circuit.

(2) the anti-theft status cannot be lifted.

The fault phenomenon is that in the winter morning, when the remote control sends out the unlock signal, the system has no normal response, the door cannot open, the car cannot start.This phenomenon may be caused by the battery voltage can not reach the alarm start voltage.The treatment method is, to confirm the storage capacity of the battery, check whether the terminal is loose and corroded, electrolyte is missing, if necessary to replace the battery.If the battery on the remote control is short of power and the signal is weak, the anti-theft status cannot be removed. At this time, just change the button battery.

4. Electronic sticky theft indicator reading essentials

There is an anti-theft indicator light installed on the table board of the car. When the electronic anti-theft system fails, the cause of the failure can be preliminarily determined by the different displays of the anti-theft indicator light.

Turn the ignition switch to “ON”. If the anti-theft indicator is ON for 3 seconds and then goes out, the electronic anti-theft system is normal.Turn the ignition switch to “ON” and if the anti-theft indicator continues to be ON 60%, the ignition key matching process is incorrect.

After turning the ignition switch to “ON” 2.5s, if the anti-theft indicator starts flashing and lasts for 60s, it indicates that there is no password chip in the ignition key or an unauthorized key is used.

Turn the ignition switch to “ON” and if the anti-theft indicator blinks immediately and persists for 60% of the time, it indicates a functional failure of the reading coil or data cable.

If you cannot find the cause of the fault, then connect the fault diagnosis instrument to test the electronic flow control system of the car.

5. Electronic anti-theft system is the match after death

Configuration of an electronic security system is required under the following circumstances:

(l) replace the battery.

(2) replace the engine electric control unit (ECU).

(3) replace the new anti-theft control module (including the combination instrument of the third-generation electronic anti-theft system), and replace the anti-theft control module removed from other cars.

(4) replace, add or lose the ignition key.

(5) use improper ways to open the door, including opening the door lock by hand and then opening the door;Break the window outside the car.

(6) use the unregistered key for more than 5 times of starting operation.

The so-called matching refers to the mutual adaptation and confirmation between ECU and electronic components, that is, the engine ECU, the anti-theft control module and the key erase the old code and write new code.When the anti-theft control module is matched with the engine ECU, it is included in the scope of the engine electronic management system.

Take passat B5 automobile (equipped with l.8t engine) as an example. The matching method of anti-theft control module and engine ECU is to connect v.a.g1552 fault diagnosis instrument and then enter 17-11-10-50.The matching method of anti-theft control module and key is 17-l1→10-21.

6. Legal issues on electronic drug theft system maintenance

(1) due to the transmission of anti-starting information, compared with the automobile without electronic anti-theft system, the engine starting time may be slightly longer.

(2) for the failure of electronic anti-theft system, replacement repair method is often ineffective.

(3) when the car needs to be parked for a long time, it should enter the anti-theft state. The operation method is to press the lock button of the remote control.This produces three effects: locking the doors; a single flashing of the turn signal;Enable pot defense kinetic energy.If the car is already out of check, the small red light (LED) on the left front door flashes periodically.After parking, if do not let the car into the theft state, not only is not safe.And the vehicle’s electrical system has been on standby, this time too long will cause the battery capacity of the day consumption (so-called leakage).Some cars parked a few days later but found no electricity, repair personnel inspection may be troubleless, often this reason is caused.

(4) new cars should not be equipped with burglar alarm at will for the following reasons:

(1) add anti-theft device must change the door lock control circuit, and the door money control circuit directly affects the work of the burglar alarm, and indirectly affect the normal work of the engine.Specifically, if the door is open but door lock switch, you can’t get a door debt security control module by iron signal switch, anti-theft control module will decided that the door did not open, the driver did not enter the car, about 25 s and then automatically enters the FangZha alert, make four car door lock to lock, and lock the engine, make it can’t start.

(2) the additional installation of anti-theft device is easy to conflict with the car’s control system, resulting in the engine can not start, because this modification operation is often not standard, resulting in excessive current, interference with the original car’s electronic control system.If you have to install extra preventer, separate it from the ignition system, otherwise it will easily cause the engine can’t start.

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