SYSTEM DESCRIPTION ENGINE IMMOBILISER SYSTEM DESCRIPTION The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses the transponder key ECU assembly that stores the key ID codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the transponder key ECU assembly sends a signal to the ECM to prohibit fuel delivery and ignition, effectively disabling the engine. FUNCTION OF MAIN COMPONENTS
SYSTEM FUNCTION (a) When the transponder key ECU assembly detects that the unlock warning switch assembly is on, the transponder key ECU assembly applies current to the transponder key coil and produces a magnetic field around the antenna coil. A transponder chip in the key grip outputs a key ID code signal using electromotive force generated by the magnetic field. The transponder key coil receives the signal and sends it to the transponder key ECU assembly. The transponder key ECU assembly checks if the key ID code received from the transponder key coil matches the registered key ID code. When the engine is started, the ECM communicates with the transponder key ECU assembly and checks the key verification result. In addition, the ECM checks if the engine ID codes stored in the transponder key ECU assembly and ECM match. If they do not match, the ECM prohibits engine start. |
Toyota Tundra Service Manual > Tire Pressure Warning System: Transmitter ID not Received in Main Mode (C2126/26)
DESCRIPTION After the tire pressure warning valve and transmitter ID registration is completed using the Techstream or ID registration was canceled via the automatic ID registration function, DTC C2126/26 is output from the tire pressure warning ECU and receiver. After ID registration is complete us ...
