Engine control module location

Anti-theft system is software programmed into the vehicle modules (computers) PCM/ECM - engine computer , BCM - body control module. Your best bet , take it to a qualified repair shop.

Passlock™ System
The theft deterrent system has been incorporated into the body control module (BCM). The theft deterrent is provided in order to prevent the vehicle operation if the correct key is not used in order to start the vehicle. The ignition key turns the lock cylinder. The cylinder rotation produces an analog voltage code in the Passlock™ sensor. This voltage code is received by the BCM. The BCM compares the voltage code to the previously learned voltage code. If the codes match, a class 2 message is sent from the BCM to the powertrain control module (PCM)/vehicle control module (VCM). The message enables the fuel injectors.
The design of the Passlock™ system is to prevent vehicle theft by disabling the engine unless the ignition lock cylinder rotates properly by engaging the correct ignition key. The system is similar in concept to the PASS-Key® system. However, the Passlock™ system eliminates the need for a key mounted resistor pellet. The components of the Passlock™ system are as follows:
• The ignition lock cylinder
• The ignition switch
• The Passlock™ sensor
• The Body control module (BCM)
• The security telltale
• The vehicle/powertrain control module (VCM/PCM)

This will not prevent the car from starting - will cause ABS light, traction control light (if equipped) and maybe weird low speed braking. Usually the fault of the lights is a bad wheel bearing/hub very common.

The EBCM (Electronic Brake Control Module) is mounted to the BPMV (Brake Pressure Modulator Valve) located at the left front (lower) engine compartment.

It looks like a (thick) flat black box.

Do you know if it is ECM/PCM or BCM controlled ?
Circuit Description (ECM/PCM Controlled)
Moving the ignition switch to the START position sends a 12-volt signal to the engine control module (ECM)/powertrain control module (PCM) Crank Request circuit. The ECM/PCM verifies that the transmission is in the PARK or NEUTRAL position. With the transmission in Park, voltage flows through the Park/Neutral position switch and feeds the starter relay coil. The PCM then grounds the control circuit of the starter relay. When the starter relay is energized it allows battery positive voltage to the starter solenoid S terminal. On some vehicles the starter will continue to crank the engine with the key released until it starts or the crank command has timed out to prevent excessive heat build up in the starter circuitry or the ECM/PCM receives an engine run flag.
Circuit Description (BCM Controlled)
Moving the ignition to the START position signals the body control module (BCM) that engine crank has been requested. The BCM verifies that theft is not active and sends a serial data message to the powertrain control module (PCM) requesting engine start. The BCM also energizes the RUN/CRANK RELAY. When the RUN/CRANK RELAY switch side closes, and the vehicle is in Park or Neutral or with the clutch is fully depressed, if equipped, supplies voltage to the starter relay coil. The PCM verifies the transmission is in Park or Neutral and the clutch is fully depressed, if equipped. The PCM will then ground the control circuit of the starter relay, closing the switch supplying voltage to the starter solenoid. On some vehicles the starter will continue to crank the engine with the key released until it starts of the crank command has timed out to prevent excessive heat build up in the starter circuitry or the PCM receives an engine run flag.

Free wiring diagrams here
http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model and engine size . Under system click on engine ,then under subsystem click on starting . Click the search button ,then click the blue link .
If you look at the diagram you will see the ignition switch ,when in start it sends B+ voltage to the ECM/PCM or depending on which system or engine to the BCM . When it see's this input it will energize the starter relay located in the under hood fuse box. This happens if the control module in charge see's another input from the PNP- park neutral position sensor and if no anti-theft system problems .
Good luck !

Without a key with anti-theft transponder inside your not starting anything . Your best bet call mobile lock smith . Anti-theft system ,software programmed into all module's involved in starting the vehicle .
The vehicle theft deterrent (VTD) system functions are provided by the theft deterrent control module. The VTD system prevents vehicle operation if a learned Passkey III (PK3) ignition key is not used to start the vehicle. Vehicles with steering column mounted ignition switches have the exciter integral with the theft deterrent control module which is located within the steering column. Vehicles with instrument panel mounted ignition switches have exciter modules separate from the theft deterrent control module with the vehicle wiring harness connecting the two. The PK3 key has a transponder embedded in the plastic head of the key. The exciter is an antenna which is made up of wire coils which surround the ignition lock cylinder. The PCM enables engine starting when it receives a learned fuel enable signal from the theft deterrent control module. The components of the VTD system are as follows:

There isn't any VTD relay on your vehicle ! You start trouble shooting by checking for DTC's diagnostic trouble codes .
The vehicle theft deterrent (VTD) system functions are provided by the theft deterrent control module. The VTD system prevents vehicle operation if a valid (learned) transponder PASS-Key®III (PK3) ignition key is not used to start the vehicle. The PK3 key has a transponder embedded in the plastic head of the key. The exciter is an antenna which is made up of wire coils which surround the ignition lock cylinder. The powertrain control module (PCM) enables engine starting when it receives a valid (learned) password from the theft deterrent control module via the class 2 serial data circuit. The components of the VTD system are as follows:
• The theft deterrent control module
• The powertrain control module (PCM)
• The ignition key (Transponder)
• The ignition lock cylinder
• The security indicator
Your best bet would be to have your vehicle taken to a qualified repair shop .

Anti-theft system problem , possibility ! Do you have a security light blinking ? Security Indicator
The security indicator is located in the clock on the top of the instrument panel. The light emitting diode (LED) displays the immobilizer system status. The immobilizer contains the LED driver hardware for direct connection of the LED.
Vehicle Theft Deterrent (VTD) Operation
The immobilizer system design prevents vehicle theft by interrupting the engine operation. The immobilizer system prevents the vehicle from starting. The engine operating functions interrupt if the immobilizer system does not recognize the transponder identification code of the ignition key. The immobilizer system and the content theft deterrent system do not interact. The system includes the following components:
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The ignition key

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The column-mounted theft deterrent module with integrated antenna

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The transponder

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The engine control module (ECM

There is no reset button.
The problem could be the anti-theft system which would knock out the injectors and spark to the plugs.
If the security light is staying on, the problem could be the chip in the key.

go online search electrical schematic / wiring diagram that shows all wiring and electrical component locator for your particular vehicle include model , year and engine size

I would try disconnecting battery again. Disconnect both cables and touch them together for a few seconds. This will reset all modules. Wierd that you had so many codes after just disconnecting battery. Sometimes very hard to tell if ecm is bad.

An immobilizer is an electronic device fitted to an automobile which prevents the engine from running unless the correct key is present. This prevents the car from being hot wired after entry has been achieved.
The microcircuit inside the key is activated by a small electromagnetic field which induces current to flow inside the key body, which in turn broadcasts a unique binary code which is read by the automobile's Engine Control Module (ECM). When the ECM determines that the coded key is both current and valid, the ECM activates the fuel-injection sequence.
The immobilizer function of the Nissan Vehicle Immobilizer System (NVIS) or Nissan Anti-Theft System (NATS) consists of the following:
- NATS ignition key
- NATS antenna amp. located in the ignition key cylinder
- Body control module (BCM) or (IMMU)
- Engine Control Module (ECM)
- Security indicator lamp


Read more: http://engine-codes.com/p1612_nissan.html#ixzz3EVZorKsl