Toyota Corolla (E120): Circuit description
When driving uphill under cruise control, in order to reduce the number of shifting due to on–off overdrive operation and to provide smooth driving, when down shifting in the electronically controlled transmission occurs, a signal to prevent upshift until the end of the uphill slope is sent from the cruise control ecu assy to the electronically controlled transmission.
Terminal ect of the cruise control ecu assy detects the shift change signal (output to electronically controlled transmission no.2 Solenoid) from the ecm.
If the vehicle slows down, also when terminal ect of the cruise control ecu assy receives down shifting signal, it sends a signal from terminal od to ecm to cut overdrive until the end of the uphill slope, and the number of gear shifts are reduced and gear shift points in the electronically controlled transmission are changed.
Wiring diagram

Other materials:
Inspection procedure
1 Inspect skid control ecu connector(+bs terminal voltage)
Disconnect the skid control ecu connector.
measure the voltage between terminals +bs (2) and gnd
(1, 23) of skid control ecu harness side connector.
Voltage: 10 – 14 v
2 Reconfirm dtc
Check the dtc .
Ok :
...
Trip information
■ Switching the display
Items displayed can be switched by pressing the “DISP” switch.
■ Odometer
Displays the total distance the vehicle has been driven.
Except vehicles with a manual transmission: Press and hold the “DISP” switch
to change the display to the Eco Driving ...
System description
The ecm uses signals from the vehicle speed sensor and crankshaft position
sensor to detect the actual
gear position (1st, 2nd, 3rd or o/d gear).
Then the ecm compares the actual gear with the shift schedule in the ecm memory
to detect the mechanical
trouble of the shift solenoid valves, th ...


