Flash: Transmission Shift Enhancements This bulletin involves selectively erasing and reprogramming the...

Bulletin number

21-035-15

Component

Power train

Summary

Flash: Transmission Shift Enhancements This bulletin involves selectively erasing and reprogramming the Transmission Control Module (TCM) with new software. The customer may experience one or more of the following: Grand Cherokee/Durango 3.6L Engine (Sales Code ERB) ? Erratic shifting complaints while driving up steep hills or towing during hot ambient temperature conditions. ? Transmission shifting does not meet customers expectation while towing a loaded trailer in high ambients (>32°C/90°F). ? Poor performance and/or poor powertrain response when trying to accelerate from speeds >58 kph (36 mph) - All Markets. ? Poor performance and/or poor powertrain response when trying to accelerate from speeds >48 kph (30 mph) - Japan/Taiwan/China vehicles only. ? Transmission shifts inconsistently (gear hunting) when driving up/down steep hills or when towing a trailer. Grand Cherokee 6.4L Engine (Sales Code ESG) ? Poor acceleration or performance above 113 kph (70 mph). ? Transmission shifting while accelerating from a stop does not meet customers expectation. ? Harsh shifting during acceleration with moderate accelerator pedal and then lifting off the accelerator pedal. ? Cannot accelerate up a steep incline or with a loaded trailer in reverse. Wrangler 3.6L Engine (Sales Code ERB) ? Erratic shifting complaints while driving up steep hills or towing during hot ambient temperature conditions. ? Hanging in gear (2nd Gear) when driving up steep hill or Towing (Rubicon ONLY). ? Transmission shifting does not meet customers expectation while towing a loaded trailer in high ambients (>32°C/90°F). ? Poor performance and/or poor powertrain response when trying to accelerate from speeds >48 kph (30 mph) - Japan/Taiwan/China vehicles only. ? Delayed Drive to Reverse shift engagement when the transfer case is in Low Range (4LO) - Rubicon Only. Wrangler 2.8L Engine (Sales Code ENS) Erratic while driving in Low Range (4LO). Transmission shifts in

Owners of these vehicles have filed 335 complaints in the transmission category.