The ECM function switches valid for the whole driving cycle are selected in the initialization of the background test and are made available in the corresponding messages. An ECM ROM malfunction is detected by using a checksum technique for verifying data. Digital data is composed of zeros and ones. A checksum is the total of all ones in a string of data. By comparing the checksum value with a stored value, a malfunction can be detected. In case of the EEPROM error, the engine symptoms will occur the running engine stall and the starting impossible.
The ECM will set a code and the Malfunction Indicator Light (MIL) will turn on if an error is detected in the ECM’s EEPROM during two driving cycles.
DTC NO. | Detecting Condition | Possible Cause |
P 0602 P 0603 | ● P 0602 EEPROM - Write error ● P 0603 ① Error is recognized if the dataset EEPROM does not answer (EEPROM - communication error) ② Error is recognized if the dataset selection in calibration does not fit with the EEPROM (Different variation number) ③ Error is recognized if the code word is incorrect or missing for the option such as the A/C, Immobilizer and cruise control ● Engine Condition : IG ON ● Fuel Limit : YES (P0603) ● Fuel Cut : YES (P0603) ● EGR OFF : NO ● MIL : YES | ECM |
