New Tech Service Bulletin Fixes 2017 Highlander and Sienna Transmission Problems
The newest generation of transmissions from Toyota have given consumers fits. However, the problem is simply the software settings Toyota chose. During a recent test by Consumer Reports (CR), the testers complained to Toyota and the company has now taken action.
Toyota Transmission Problems
The issues are simply drivability. CR reported, "The transmission made the engine rev before upshifting, especially from second to third gear, even under light acceleration. This delayed shifting increased engine noise and made driving rather unpleasant." This sounds very much like the problems that Tacoma owners suffered through before a technical service bulletin (TSB) addresses that issue.
Toyota Fuel Economy
Toyota is making these odd software settings in order to maximize fuel economy. However, it comes at the cost of driving enjoyment. The fuel economy did go up as a result of Toyota's weird settings. No word on if the TSB removes that advantage.
Toyota Transmission TSB and Fix
The correction can be done at any Toyota dealer in about 45 minutes according to CR. The TBS numbers are TSB-0194-17 for the Highlander and TSB-0197-17 for the Sienna