OBD (On-Board Diagnostic) System Description: Notes

ECM in this vehicle has the following functions in compliance with OBD-II regulations.

• When the ignition switch is turned ON with the engine at a stop, malfunction indicator lamp (MIL) (1) turns ON to check the MIL (1) and its circuit.
• When ECM detects a malfunction which gives an adverse effect to vehicle emission while the engine is running, it makes MIL in the meter cluster of the instrument panel turn ON or flash (flashing only when detecting a misfire which can cause damage to the catalyst) and stores the malfunction area (DTC according to SAE J2012) in its memory.

  (If it detects that continuously 3 driving cycles are normal after detecting a malfunction, however, it makes MIL turn OFF although DTC stored in its memory will remain.)

• As a condition for detecting a malfunction in some areas in the system being monitored by ECM and turning on MIL due to that malfunction, 2 driving cycle detection logic is adopted to prevent erroneous detection.
• Malfunctions detected by ECM are stored in its memory as pending DTC, confirmed DTC (current and history) and permanent DTC. The permanent DTC, among others, will be stored in the memory that cannot be manually erased. (For the details, refer to description on PERMANENT DTC (EVAP LEAK CHECK MODEL) )
• When a malfunction is detected, engine and driving conditions are stored in ECM memory as freeze frame data. (For the details, refer to description on FREEZE FRAME DATA )
• It is possible to communicate via DLC (data link connector) (3) by using not only SUZUKI scan tool (SUZUKI-SDT) (2) but also CAN communication OBD-II generic scan tool which are in compliance with SAE J1978. (Diagnostic information can be accessed by using a scan tool.)
  Fig 1: Identifying Malfunction Indicator Lamp, Scan Tool And DLC

  Courtesy of SUZUKI OF AMERICA CORP.