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 troubleshootingAutomatic transaxle assembly
Components
Removal
Remove engine assembly with transaxle
Remove the engine with transaxle (see page em-
98).
Drain automatic transaxle fluid
Remove the drain plug and gasket, and drain atf.
Install a new gasket and the drain plug.
Torque: 47 n*m (479 kgf*cm, 35 ft. ...
Emission inspection
and maintenance (i/m)
programs
Some states have vehicle emission inspection programs which
include obd (on board diagnostics) checks. The obd system
monitors the operation of the emission control system.
If the malfunction indicator lamp comes on
The obd system determines that a problem exists somewhere in the
emission contr ...
Open in occupant classification ecu battery positive line
Description
Dtc b1794 is set when a malfunction is detected in the occupant
classification ecu battery positive line.
Wiring diagram
Inspection procedure
Check for dtc
Turn the ignition switch on.
Clear the dtcs (see page rs-249).
Hint:
First clear dtcs stored in the ...