939003538 - 5580E ANTI-THEFT DEVICE
ALFA ROMEO CODE SYSTEM
The vehicles are equipped with an electronic system known as the ALFA CODE to produce the engine immobilizer function.The ALFA CODE system only allows the engine to be started by means of the NCM after a secret code, memorized previously in the NCM, is received.The second generation Code system is incorporated in the Body Computer Node (NBC).The ALFA CODE system comprises 5 basic components (in addition to the Body Computer which acts as a control unit):- CAN line for dialogue between the NBC and the NCM- two-way serial line for recovery (W line);- two TEG devices (electronic key) containing a transponder with a secret code;- an aerial that reads the code contained in the TEGs;- the NCM.1 - NBC2 - NCM3 - Aerial in the TEG Reader4 - TEG (electronic key)Operation
The ALFA CODE allows the start of the engine management by the NCM by means of a coded dialogue between the NBC and NCM during the stage that precedes start up.After key on - i.e. TEG correctly inserted in the TEG Reader - the NCM sends a code reques to the NBC, which responds only after it has identified (via its aerial) the presence of a known TEG in the TEG Reader.If the secret code in the answer is valid, the NCM continues with the regular engine management activities, allowing the engine to be started up.The NCM can only memorize the secret code through a special procedure.Operation of the ALFA CODE is guaranteed if any of the other NBC functions are not working properly.After recognizing an enabled transponder, the ALFA CODE switches off any alarm system.Interaction between the alfa roce and the electronic key (teg)
Every TEG contains a transponder with an IDENTIFICATION CODE and a SECRET CODE.As soon as the TEG is inserted, the transponder sends the identification code to the ALFA CODE which, having recognized it as one of the enabled ones, continues with the cryptographic transponder recognition strategy.If the identification code is not recognized, the procedure is aborted and the engine cannot be started.The cryptographic transponder is recognized by means of a challenge-response algorithm with an encrypted code exchange.The code recognition time is less than 160 ms per attempt.The ALFA CODE attempts transponder acquisition for up to 1 second.Communication between the engine control node and the alfa code
Communication between the ALFA CODE (NBC) and NCM takes place via the C-CAN in normal service conditions. Every exchange of information between the ALFA CODE and the NCM is guided by the NCM (ALFA CODE never interrogates the NCM but only responds after receiving a request).After KEY-ON, the flow of code exchange operations between the ALFA CODE and the NCM depends on the status (blank or memorised) of the engine control unit.If the NCM is blank, the procedure involves sending a fix-code request to the NBC: in this way the NCM learns the secret code and stores it in its memory. This procedure is known as CODE RECORDING.If the NCM has already been stored, the procedure involves checking that the fix-code stored in the engine management control unit memory and the one memorized in the NBC correspond: the NCM asks the NBC for the secret code and compares it with its own. This procedure is known as CODE VERIFY.1 - Key-on2 - NCM initialisation3 - NCM status memorised/blank4 - Memorisation successfully completed?5 - ENABLE ENGINE MANAGEMENT = the software flow continues with engine management6 - PROHIBIT ENGINE MANAGEMENT = activates a timer that imposes a delay to enable a new procedure only after 0 - 600 s. The +15 supply must be turned off and then on again. If no timer is available (con +30), it will be necessary to wait with key-on for 0 - 600 s. After this, a new procedure can be run, i.e. KEY- OFF and KEY-ON7 - Is the secret code valid?8 - SEE POINT 69 - SEE POINT 5A - CODE VERIFYB - CODE RECORDINGCode recording
The CODE RECORDING procedure is the memorizing of the fix code in the engine control unit.Only after the ALFA CODE has memorized the identification codes, the secret code and the fix code, is it ready to satisfy the request to transmit a code from a blank NCM.After power on, the engine control unit initialises its software and requests a fix code if it is blank.If the ALFA CODE is not blank, it responds by sending the fix code, but only after having recognized an authorized TEG. If the TEG is not authorized (unrecognized) or there is no TEG inserted, the ALFA CODE does not respond.When the ALFA CODE is blank, the aerial contains no transponder and a PER (fix code request) is sent from the NCM to the ALFA CODE, the ALFA CODE does not respond.Code verify
This standard procedure is repeated throughout the vehicle lifetime whenever the user inserts the TEG in the Reader (KEY ON): this procedure enables the starting of the engine if the TEG is inserted and enabled.The code verify procedure continues even when the user presses the START/STOP key (CRANKING).After KEY ON (+15), the ALFA CODE detects whether the TEG transponder has been enabled.At the same time as KEY ON, the NCM initializes its software until it verifies whether a fix code has been memorized. If the answer is yes, it sends a fix code request to the ALFA CODE.In response to this request, the ALFA CODE only sends the fix code, encrypted by the Minikrypt, to the engine control unit if the transponder is recognized as enabled.If the ALFA CODE receives further fix code requested, it only needs to re-read the transponder in the aerial before responding to the NCM if visible signs of tampering are present (see later).If the transponder is not recognized (incorrect transponder, no transponder in the aerial, etc.), the ALFA CODE will send the code (incorrect transponder or missing transponder) to the engine control unit.If the ALFA CODE is blank and the NCM sends a fix code request, after having recognized the transponder, the ALFA CODE responds by sending a blank NBC transponder recognized code message encrypted by the Minikrypt.Method of using c-can or recovery line w
Communication between the NBC and NCM takes place along the C-CAN line by default: if the C-CAN line is faulty, the recovery strategy is as follows:- C-CAN faulty- the NCM changes to recovery status on the W serial line and requests the code from the NBC: if the outcome is positive, start-up is permitted.- in the event of problems on the W line, the NCM transfers to recovery status by means of the Diagnostic instrument at the end of the retransmission attempts.The recovery strategy is mainly managed by the NCM, which acts as a master unit during communication: the NBC, acting as the slave unit, must always be ready to respond to code requests from the C-CAN network and also from the W serial line.Communication via the c-can network
Communication via the Body Computer and the NCM takes place via the following two CAN messages:- IMMO CODE REQUEST (immo code request)- IMMO CODE RESPONSE (immo code response).The MMO CODE REQUEST is sent by the NCM and received by the NBC.The MMO CODE RESPONSE is sent by the NBC and received by the NCM.Communication via the w line
If the system changes to recovery mode due to a malfunction in the CAN network, information must be exchanged between the NCM and NBC via the W serial line.This code exchange is only carried out for the CODE VERIFY procedure: it is not therefore possible to run a CODE RECORDING procedure via the W line.Information must be exchanged via the serial line in exactly the same way as via the C-CAN network: The NCM control unit is the communication master unit while the NBC control unit responds to requests received by the NCM.Both messages - IMMO CODE REQUEST and IMMO CODE RESPONSE - are carried on the serial line.Checking the w line electrical connection
Because communication only takes place on the W line in recovery mode, an ERROR status would not not be recognised until the system was used i.e. because the customer would not be able to move the vehicle.A strategy for checking the W serial line has therefore been added so that the line can be diagnosed.Protection codes
The ALFA CODE function is performed via the exchange of secret codes between system subunits (TEG, NBC, engine control unit).- UNIVERSAL CODE this is the code that an unprogrammed ALFA CODE sends to the NCM when it detects the presence of a transponder in the TEG. The ALFA CODE warning light turns on at a frequency of 1.6 Hz and duty cycle of 50%. The warning light flashes to indicate that the system is properly connected but the vehicle is not protected by a code.- IMMO CODE: This is the basic code that provides the secret code and the fix code. An automatically generated immo code is allocated to each vehicle. The IMMO CODE is used to generate all the other secret codes used by the ALFA CODE function.- SECRET CODE: This code is resident in the transponder. It is stored in the transponders contained in the TEG when the transponders are programmed and in the ALFA CODE when the keys are programmed at the end of line.- FIX CODE: This is stored in the ALFA CODE during end of line programming.- ELECTRONIC CODE (PIN): This is obtained from the fix code and printed on the CODE CARD, which is given to the vehicle owner. It takes the form of a 5-figure decimal code (0 is not permitted).It is used to access the NBC memory in protected mode in order to reprogram or program new remote control units (TEGs) and/or perform specific diagnostic functions.It is also used in the accelerator pedal recovery procedure described in the specific section on the engine control unit.- IDENTIFIER: This is resident in the transponder and different for each transponder. It is stored in the ALFA CODE during the programming procedure. The ALFA CODE manages a table of enabled identifiers and another table of disabled identifiers.Alfa code function in the nbc
The ALFA CODE is a function of the NBC.The main ALFA CODE functions are:- to detect insertion of the TEG in the TEG Reader (+15);- to place the alarm in a deactivated state after recognizing an enabled TEG;- to emit an electromagnetic field to read the TEG transponder;- to send the random code to the transponder;- to receive the encrypted code transmitted by the TEG;- to store up to 8 identification codes;- to store the secret code;- to manage a list of up to a maximum of 8 enabled identification codes;- to manage a list of 16 permanently disabled identifiers.- to manage the C-CAN line towards the engine control unit;- to control activation of the warning light on the panel via communication with the NQS;- to carry out self-diagnosis.Aerial
The aerial in the TEG Reader is powered by the NBC to energise the TEG transponder.Since the aerial needs to be as close as possible to the transponder (on account of electro-magnetic immunity, the limited range of the transponder and small dimensions) it is fastened to the front part of the TEG-Reader.Transponder (in the teg)
A cryptographic transponder is located inside the TEG.Operation
At the time of Key On (+15), the transponder is energised by the aerial and responds by emitting a rolling, encrypted secret code.The emission into the atmosphere is sufficiently powerful to produce a high immunity to electromagnetic interference and the range is such that it can be received by the aerial in the TEG READER..If the code is recognized as valid, the ALFA CODE sends the engine control unit, on request, a coded signal allowing the engine to be started.Up to 8 electronic keys (TEGs) can be stored in the ALFA CODE. | The TEGs are supplied already memorised by the production plant. All the codes are also stored in a database managed by Parts. When the new vehicle is delivered to the customer, the service network does not need to carry out any memorisation procedure. If the TEGs are lost or extra TEGs are required, order from Parts in accordance with the procedures described below and in the REPAIR PROCEDURES section. Op. 5580E ANTI-THEFT DEVICE |
Specifications
The transponder in the TEG has the following coded in its memory:- SECRET CODE which is the same for each transponder in the same kit;- IDENTIFICATION CODE which is different for each transponder produced;- PROGRAMMING DATE for the secret code- The identification code differs from transponder to transponder to guarantee that no two transponders have the same identification code even if there is a request for a duplicate in the Network.Programming the teg
The memorisation procedure is divided into two stages in sequence:- the transponder in the TEG is stored in the ALFA CODE;- The ALFA CODE manages memorisation of the fix code in the engine control unit.This second stage is implemented automatically when the first is completed successfully after key on.The transponders are sent to the TEG manufacturer programmed with the identifier (different for each transponder).The manufacturer generates an immo code, computes the relevant codes (secret code, fix code) and programmes the secret code and the programming date in the transponders.Once programmed, it prints a bar code on a disposable label that contains the immo code, the TEG identifiers, the programming date, the emergency key mechanical code (door opening) and, if present, the remote control/alarm codes.The secret code in the TEGs is stored in the ALFA CODE during the end of line programming procedure and is used for TEG identification in the cryptographic algorithm.Programming a new body computer
If the Body Computer is replaced, the ALFA CODE must be programmed with the secret code and fix code of the vehicle to which it will be installed.The database is accessed using the chassis number to obtain the vehicle immo code. This is used to supply the secret code and fix code, which are programmed in the NBC.For a new NBC, the tables of enabled and disabled identifiers are new.Once the NBC has been installed in the vehicle, the TEG identifiers are stored (see reprogramming). | An ALFA CODE programming operation can only be performed with a blank NBC by the ALFA ROMEO parts dept. |
Reprogramming the teg
TEG reprogramming involves storing the TEGs enabled upon vehicle start-up in the NBC.N| ... DATA ERROR - CROPPED TEXT | Ошибка данных - Текст обрезан ... |
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