See Figures 1 through 6
The EEC-V (OBD II) codes differ from the 2 or 3-digit codes of the (former) EEC-IV system in that they are accompanied by a letter prefix before a 4-digit number. Example: P0102 would indicate a Mass Air Flow (MAF) Sensor circuit (low input).
The number of digits used in the OBD II codes, along with the letter prefix makes flash diagnosis all but impossible, so no provision has been made in OBD II systems to read codes in any other way than with a scan tool.
When diagnosing the OBD II EEC-V system, the New Generation Star (NGS) tester or generic scan tool may be used to retrieve codes, view the system operating specifications or test the system components. There are also several other pieces of equipment which may be used for diagnosis purposes.