For CCM readiness, language between 1968.2 reg, and J1979 DA may be interpreted to mean CCM support is mandatory irrespective if the ECU contains any DTC’s that contribute to CCM readiness determination. GM has a DEC ECU that does not have any CCM input rationality or output functional monitors and has concluded that CCM Readiness should not be supported in this case. GM is recommending clarification in the comment for the F501 CCM Readiness Support bit.
Regulatory Reference:
1968.2: (g)(4.1.2) For vehicles using SAE J1979-2:
(A) In accordance with SAE J1979-2 specifications, the OBD II system shall indicate “complete” or “not complete”
since the fault memory was last cleared for each of the installed monitored components and systems identified in sections (e)(1) through (e)(16), and (f)(1) through (f)(16).
(xiv) Gasoline Comprehensive Component: input component rationality fault diagnostics, output component/system functional checks, sections (e)(15.2.3)(A)(i) through (iii), (e)(15.2.3)(B)(i)b., (e)(15.2.3)(B)(ii)b., and (e)(15.2.3)(C) through (F)
