- 2001–2003 Factory-verified
JL4 Factory-verified
Also documented for BuickCadillacChevroletGMCHummerPontiacSaturn
Documented applications
- 2000–2002 Factory-verified
the 2000 list names it "Precision Control System"
This page aggregates every documented appearance of JL4 in the Oldsmobile reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.