Innovate Motorsports LM-2 - Manual (Page 30)

Document # 31-0008 LM2_Manual_1.3.doc 30
(ISO 15765 standard or extended) but that still leaves about 12 years of ‘compromise’
vehicles. Fortunately the LM-2 can take care of most of this complexity automatically.
So, from a user’s point of view OBD-II can primarily be considered on the basis of what
is consistent and standard, namely:
• The
Connector
• The Information Provided
OBD-II information comes in two basic flavors, “PIDs” and “DTCs”. PIDs, or
“Parameter IDs”, represent real time measurements about the state of the power plant;
information such as RPM and ignition timing. The definitive reference on these
standard PIDs is the J1979 Standard (last revised 4/2002), published by the SAE
International (www.sae.org). Not all ECUs support all PIDs, but the LM-2 understands
and converts over 100 of the most common ones (see Appendix B for a complete list).
DTCs, or “Diagnostic Trouble Codes” are, as the name implies, problems reported by
the ECU. Codes can be “Standard” or “Manufacturer Controlled”. An example of a
standard code would be P0051. This code means”HO2S Heater Control Circuit Low,
Bank 2, Sensor 1” for all OBD-II vehicles. But P1336 is in the non-standard code range.
The exact meaning is up to the vehicle maker. Without information from the car maker
all we know from the code itself is that the beginning, P13xx, suggests that it is in the
general category of “Ignition System or Misfire.”
The definitive listing of standard DTCs is J2012 (last revised 4/2002), also published by
SAE International. All these standard DTCs are reported as both a number and in plain
English by the LM-2. Manufacturer Controlled DTCs are reported solely by number.