When the ignition is turned on, the controller communicates with the immobilizer control unit, designed to prevent unauthorized starting of the engine
In this case, the operation of the engine is possible if the controller has received the correct password from the control unit.
The car anti-theft system consists of a control unit 1, a system status indicator 3 located in the instrument cluster 2, a communication coil 5 structurally located in the ignition switch 4, a learning key 6 with a red container 7, a remote control - a working key 8 , and the corresponding part of the engine control system controller program.
The APS operating modes and states are displayed using the APS signaling device and a buzzer inside the APS control unit.
The APS control unit is connected to the controller via a diagnostic line.
The control unit has a built-in relay that connects or disconnects the diagnostic block from the controller.
If a device is not connected to the diagnostic block, the relay opens the diagnostic circuit, and the line is used to communicate with the controller and the control unit.
When the device is connected to the diagnostic block, the relay closes the diagnostic circuit, which allows the exchange of information between the device and the controller.
The APS control unit has priority over the diagnostic tool when working with the controller, and if necessary, the control unit interrupts the connection between the controller and the diagnostic tool (for example, to exchange information between the control unit and the controller when starting the engine).
The APS controller and control unit can be in one of two states:
- - with the immobilization function disabled ("clean"). In this state, the controller and the APS control unit do not represent a single system and engine start is allowed regardless of the APS;
- - with the immobilization function enabled ("trained"). In this state, engine operation is possible only when the ECM receives the correct password from the APS control unit.
The controller and the APS control unit enter the trained state after the procedure for learning the working ignition keys, performed using the learning key.
You can train either "pure" keys, i.e. those who have never studied before, or those who have already worked with this particular APS.
The training key that was used to perform the procedure stores the system password and is recommended to be used only for performing training procedures.
When they are executed, a new password is generated in the system, which is stored in the non-volatile memory of the controller and the APS control unit. This new password is also written to the learning key.
The learning key cannot be used to teach any other pair of APS control unit - ECM.
The immobilizer control unit is mounted on a bracket under the instrument panel console screen on the left side.
To remove the block, disconnect the negative battery cable.
Removing the lining of the floor tunnel
With a 10 head, we unscrew the two nuts securing the control unit
Disconnect the wiring harness block from the block
Install the block in reverse order
Removing and installing the remote control system unit
In the pictures, the instrument panel has been removed.
Disconnect the negative battery terminal.
Using a 10 key, we unscrew the two nuts securing the block and remove the block
By pressing the latch, we disconnect the block of wires from the block
The unit is marked on its body
Install the control unit in reverse order
