Editor's note: An earlier version of this story incorrectly described the amount of time needed by dealer technicians to test a software upgrade on the Jeep Cherokee's nine-speed automatic transmission. The optional test drive should take no more than 78 minutes.
DETROIT -- Chrysler Group continues to tweak the software that operates the complex nine-speed automatic transmissions it will use to power all of its front-wheel-drive-based vehicles.
A new software recalibration covers more than 100,000 Jeep Cherokees built before May 5 to address continuing issues with the way some of the nine-speeds shift gears.
Chrysler delayed the launch of the Cherokee for almost two months last year to tweak the transmission's software.
In addition to a five-minute software reset or "reflash," a May 15 technical service bulletin advises technicians in certain cases to perform an "adaptation drive learn" -- taking the Cherokee out for a test drive of up to 78 minutes to ensure that it is shifting correctly.
Like many electronic transmissions, the nine-speed learns the driving habits of its main driver and adapts the shift patterns accordingly.
Not all sold Cherokees require the reflash, according to the automaker, but it is available under warranty to customers who complain about the feel or operation of the transmission.
In a written statement, a Chrysler spokeswoman said the reflash was being done "to respond to customer feedback and improve satisfaction." She said dealers were "asked to perform the software update on any unsold vehicles in inventory and for any customer who has requested improved throttle response or shift feel."
This is the third technical service bulletin and second software reflash Chrysler has issued for the transmission since the Cherokee went on sale in October.
About half of the 30 consumer complaints filed against the 2014 Cherokee on the National Highway Traffic Safety Administration's safercar.gov concern the operation of its transmission and powertrain.
According to dealership parts records, Chrysler stores in the United States are ordering an average of about a dozen replacement Cherokee transmissions collectively per week under warranty.
The Cherokee is the first Chrysler vehicle to use the nine-speed transmission. The second, the 2015 Chrysler 200 sedan, began arriving in dealerships this month. Ultimately, Chrysler plans to spread the nine-speed across its lineup of fwd-based vehicles.
CEO Sergio Marchionne said last week that he was not concerned about the quality of the nine-speed automatic, and that it will get better.
"There are always teething issues with every transmission I've ever built, and I mean that literally," Marchionne told reporters at an event in Michigan. "We keep tuning the transmission more and more as we get more familiar with it.
"I'm never satisfied, but I think I'm OK with its application in the current car," Marchionne said. "It will get better six months from now, trust me."
Kathleen Burke contributed to this report.