SMK & PM (ECM/TCM) Control Module (SMARTRA Error)
When turning the ignition switch ON or cranking the engine, the engine ECM begins communication with the Smart Key unit (SMK IMMO unit) by sending a VIN (Vehicle Identification Number) request signal to control the engine in a stable manner.
The Smart Key unit sends an 'Ignition Approval Not Possible' signal to the engine ECM when the Immobilizer cannot function. In this case, the engine ECM enters an ignition inhibition state and a driver cannot start the engine (ignition or fuel sparying inhibited).
On the other hand, the Smart Key unit sends an 'Ignition Approval' signal to the engine ECM including the VIN and learnt status information when the Immobilizer can function.