The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingRemoval
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove fan and generator v belt
Remove the belt (see page em-6).
...
Child restraint systems with a top tether strap
Secure the child restraint system
using the seat belt or
latch anchors.
Latch the hook onto the anchor
bracket and tighten the top
tether strap.
Make sure the top tether strap is
securely latched.
Laws and regulations pertaining to anchorages
The latch system conforms to fmv ...
Customize parameters
Notice:
When the customer requests a change in a function,
first make sure that the function can be customized.
Make a note of the current settings before
customizing.
When troubleshooting a function, first make sure that
the function is set to the default setting.
Combination me ...