Owners of a 2001-2004 Rav4 often complain of abnormal shifting, sometimes in conjunction with a check engine light and shift solenoid codes (P0750, P0753, P0755, P0758 and/or P1760). The 2-3 upshift can be particularly harsh, the condition can come and go, and in many cases is incorrectly diagnosed by aftermarket shops unfamiliar with the problem. The problem is so widespread Toyota extended that warranty for this specific issue to 10 years or 150k miles. CARspec had a 2003 Rav4 with this condition last night and we wanted to share our solution to help others that may have the same issue.
In the majority of cases this condition is caused by the Engine Control Module (the main control brain of the car). For reasons unknown, the symptoms start to appear around 80k miles and gradually worsen over time – harsh shifting, poor gear kickdown, and abrupt starts from a stop. The symptoms can come and go, but never disappear entirely. Driving with the symptoms can potentially lead to transmission failure, requiring the replacement of both the module and the transmission.
Toyota offers an updated Engine Control Module for the condition which corrects the condition for most owners. While relatively expensive, the repair is effective in alleviating the harsh shifts and preserving the life of the transmission.
We hope this helps any Rav4 owners or other technicians correctly identify this issue and get it resolved!