You can minimize the risk of damaging an ECU by understanding the following precautions:
1. Battery must be fully charged and in good condition. BATTERY VOLTAGE MUST NOT FALL BELOW 11.4 VOLTS OR RISE ABOVE 16.0 VOLTS DURING THE REPROGRAMMING PROCESS.
2. All electrical accessories must be turned off and electrical loads must not be altered significantly during the reprogramming process (i.e. audio system, air conditioning system, interior lighting, daytime running lights, etc)
3. The engine compartment hood must be open and under hood ambient temperatures must not exceed 158oF
4. Scantool/J2534 interface cables must be in good condition and connections must be electrically sound prior to beginning reprogramming (see TSB SS004-01, "ECU Flash Reprogramming Error Message" for more detail).
5. Do not disconnect the scantool, J2534 interface or PC during the reprogramming process; FAILURE TO FOLLOW THIS INSTRUCTION WILL RESULT IN PERMANENT DAMAGE TO THE ECU.