Description & Operation
WARNING: This page is about a different car, the 2000 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Deactivate air bag system before performing any service operation. See AIR BAG RESTRAINT SYSTEMS article.
DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.
The engine immobilizer system consists of an Engine Control Module (ECM), transponder key coil, transponder key amplifier and key with built-in transponder chip. See Fig 1. When ignition key is inserted in ignition, the transponder chip in the key transmits an electronic code to the transponder key coil. The signal is amplified, and read by the ECM. The engine will start only when the key code is the same as the code registered in the ECM. System is reset each time key is removed from ignition switch.
If a problem exists in the engine immobilizer system, a Diagnostic Trouble Code (DTC) may be stored in the Engine Control Module (ECM), but the Malfunction Indicator Light (MIL) on instrument cluster will not illuminate.