AGM-154C was upgraded to AGM-154C-1 in the late decade of 2000 whereas AGM154C was already in use by 2005.
AGM-154C had an IIR tracker already.
AGM-154C variant incorporates a 500-pound blast/fragmentation/penetrator warhead effective against fixed-point targets such as industrial facilities, logistical systems, and hardened tactical targets. The AGM-154C incorporates an uncooled, long-wave imaging infrared seeker with autonomous target acquisition algorithms for precise targeting.
The AGM-154C was approved for full-rate production in December 2004. The initial operational capability was achieved in February 2005. Integration of a weapon data link and updated seeker software algorithms (termed AGM-154C-1 variant) began in the fiscal year 2006 to provide a capability against at-sea moving/relocatable targets in fiscal 2010.
Info is taken from "https://www.military.com/equipment/agm-154-joint-standoff-weapon"