Bajaj released the UG IV (fourth upgrade) versions of the Pulsar 150 and Pulsar 180 in April 2009. The upgrades for the Pulsar 150 included an all-black theme, tank scoops similar to those on the Pulsar 200, a 3D Pulsar logo, and a changed electrical system (full DC). Power also increased from 13.5 HP to 14.09 HP (at 8,500 rpm).
Electrical enhancements like auto head light switch-off after few seconds of turning the engine off to protect the battery, self-cancelling turn signals, icon illumination (horn icon, indicator icon, engine cut off icon, etc.), side stand warning light, duel digital trip meter, low fuel warning light (which also flashes when the engine is revved too hard), and low battery indicator are common features among all the variants and Auto Choke System in 220 Variant.
The Pulsar 180 received upgrades like wider tyres, split seat, tank scoops, clip-on handlebars, 3D Pulsar logo, swing arm suspension borrowed from Pulsar 200, and thicker forks. The power was increased to 17 PS.[21]
Bajaj launched a carbureted version of Pulsar 220 on June 2009, tagging it as "the fastest bike in India".[22] It also discontinued the production of Pulsar 200 on July 2009.
Bajaj also introduced a new Light Sports version of Pulsar named as Pulsar 135LS. It is the first bike in India to contain 4-valve DTS-i technology. It consists 4 smaller valves rather than 2 standard bigger valves, styling also is changed and looks become more aggressive. The bike is ARAI certified for 68.5 km/l and weights only 122 kg.