The 2016 Lexus RX introduced the Aisin 8-speed automatic transmission for smoother, more efficient operation, but harsh shifting accompanied by P0700 indicates the transmission control system has detected a fault. Understanding this refined transmission helps identify whether simple maintenance or more significant repairs are needed.
Aisin 8-Speed Transmission in the RX
The AWR80 8-speed automatic provides wider ratio spread for improved fuel economy and acceleration. The transmission adapts to driving style through continuously updated shift calibrations. Toyota/Lexus transmissions are renowned for reliability, so shift quality issues typically indicate addressable causes rather than inherent design problems.
Understanding P0700
P0700 is a generic code indicating the TCM has stored specific fault codes requiring retrieval with Toyota/Lexus diagnostic equipment. The code itself doesn't diagnose the problem—it signals that transmission-specific codes exist. Harsh shifting may result from hydraulic, electronic, or adaptation issues.
Common Causes of Harsh Shifting
Transmission fluid degradation affects shift quality and clutch engagement. Adaptive values may become corrupted from battery issues or module faults. Shift solenoid problems affect specific gear transitions. Torque converter lockup issues can feel like harsh shifting at cruise speeds. Internal clutch wear, while less common in Lexus transmissions, can cause harsh engagement.
Diagnostic and Service Approach
Retrieve Toyota/Lexus-specific transmission codes. Check fluid level and condition using the proper procedure. Review current software version and available updates. Perform adaptation reset through diagnostic equipment. If issues persist, further diagnosis of solenoids or internal components is necessary.