STEP 1. Using scan tool MB991502, read the immobilizer diagnostic trouble code (DTC).

To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502. (1) Connect scan tool MB991502 to the data link connector. (2) Turn the ignition switch to the "ON" position. (3) Read the immobilizer system-DTC (4) Turn the ignition switch to the "LOCK" (OFF) position. Q: Is the immobilizer system-DTC is output? YES: Refer to GROUP 54A, Ignition Switch and Immobilizer System - Diagnostic Trouble Code Chart . NO: If DTC P0513 is output again after the MFI-DTC has been erased, replace the ECM <M/T> or PCM <A/T>. Then check that the DTC P0513 does not reset.