New TSB issued today for 2011 WK2 (5.7L models)
Flash: Driveability And Transmission And Heating And A/C Improvements
This Service Bulletin applies to WK vehicles equipped with a 5.7L engine (Sales Code EZH) and 545RFE transmission (Sales Code DGJ) built before April 4, 2011
This bulletin involves flash reprogramming the Powertrain Control Module (PCM) with new software.
Heating And A/C Improvements
a. A/C not cooling enough or feel a warm air burst. This condition happens if 3 to 4 wide open throttle event happen during the same drive cycle or when towing a trailer.
b. Heater warm-up time is too slow at or below 14° F (-10° C). Idle RPM has been increased for improved heater warm-up times.
c. Loud cooling fan or fan run on high for long periords with the A/C on.
a. Fuel odor. This condition is noticeable in hot ambient temperatures, while towing a trailer or in stop or go city traffic. Purge flow has been increased.
b. Lacks Performance. Some driving conditions can produce circumstances where some customers may perceive more pedal effort is required to get the Powertrain to accelerate the vehicle as desired. The PCM calibration for pedal vs. torque relationship was changed to allow for more torque delivery at less pedal effort/travel.
c. Knock sound. This condition happens on heavy throttle input or entry into or out of MDS modes. The spark knock calibration has been changed to accommodate these conditions.
f. Cruise Control cancels without driver input while in ACC mode at about 5800 RPM. To correct this condition the cruise control cancel mode RPM limit has been raised.
a. Bump feeling or clunk sound in 4WD Low during a coast down. This condition happens at speeds between 5 to 30 mph followed by the driver letting off on the throttle (Decel). (WK Body International Vehicles Only)
b. Too high vehicle speed needed before shifting from 3rd - 4th gear.
c. Shudder or shake feeling on wide open throttle stab.
d. Harsh 1-2 upshift.
Download PDF copy here: