Circuit Description
WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
The ECM uses signals from the VSS to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear). The ECM then compares the actual gear with the shift schedule in the ECM memory to detect mechanical troubles of the shift solenoid valves and valve body. See Figure. Possible causes are:
- Shift solenoid valve SL1, SL2, SL3, S4 or SR is stuck open or closed.
- The valve body is blocked or stuck.
- Torque convertor clutch malfunction.
- Automatic transaxle malfunction.