Communication With Scan Tool MB991502 Is Impossible

Immobilizer-ECU is energized when the ignition switch is turned to ON position and the MFI relay is turned on. The ECM (M/T) or PCM (A/T) transmits a signal from Scan Tool MB991502 to the immobilizer-ECU as it is. In the same way, a signal from the immobilizer-ECU is also transmitted to Scan Tool MB991502 as it is.