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 troubleshootingDifferent diameter tire malfunction
Description
The skid control ecu measures the speed of each wheel by receiving signals
from the speed sensor.
These signals are used for recognizing that all 4 wheels are operating properly.
Therefore, all wheel
signals must be equal.
Inspection procedure
Check tire size
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Tc and cg terminal circuit
Description
Dtc output mode is set by connecting terminals 13 (tc) and 4 (cg) of the
dlc3. The dtcs are indicated
by the blinking of the tire pressure warning light.
Wiring diagram
Hint:
When each warning light continues blinking, a ground short in the wiring of
terminal tc of the dlc3 ...
Glossary of sae and toyota terms
This glossary lists all sae-j1930 terms and abbreviations
used in this manual in compliance with sae
recommendations, as well as their toyota equivalents.
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