Suzuki 2000 Grand Vitara SQ625 Service Manual page 97

ENGINE DIAGNOSIS (G16 / J20 ENGINES) 6-93
DTC P0601 (DTC No.71) INTERNAL CONTROL MODULE MEMORY CHECK SUM ERROR
SYSTEM DESCRIPTION
Internal control module is installed in ECM (PCM).
DTC DETECTING CONDITION AND TROUBLE AREA
DTC DETECTING CONDITION TROUBLE AREA
Data write error or check sum error ECM (PCM)
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool.
3) Start engine and run it at idle if possible.
4) Check DTC and pending DTC by using scan tool.
TROUBLESHOOTING
Substitute a known-good ECM (PCM) and recheck.