The effectiveness in diagnosing automatic transmission malfunctions is an art form. Although there are similarities among the wide varieties of transmissions on the road, each transmission has its own peculiarities. Aside from having mechanical, hydraulic, and electrical hardware systems to contend with, software/programming issues and various vehicle platforms make diagnostics much more difficult. Using scopes provides
The focus of this article is the Toyota AB60, as it has a nice balance of five on/off solenoids: S1, S2, S3, S4, and SR. In addition to those, there are 4 PWM solenoids: SL1, SL2, SLT, and SLU, which all operate at about 335 Hz. The test vehicle is a 2008 Toyota Tundra equipped with a 5.7L engine.
The Toyota/Lexus A761, AB60 and A960 6-speed transmissions have been showing up in shops more frequently over the last couple of years. Warranties are expiring and people seem to be hanging on to their vehicles longer these days. Even so, there are a number of different issues with these transmissions, including torque-converter clutch failure that is especially chronic with AB60 Tundra applications. Common to all these units is a problem that sticks out a bit more than the others, though: on-off solenoid mechanical fault codes. You’ll see these as P0751 S1 solenoid performance, P0756 S2 solenoid performance, P0761 S3 solenoid performance and P0766 S4 solenoid performance codes.