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:
On–vehicle inspection
1. Inspect pressure switch no.1.
Magnetic clutch control:
inspect pressure switch operation.
Set on the manifold gauge set.
Connect the positive (+) lead from the ohmmeter to
terminal 4 and the negative (–) lead to terminal 1.
Check continuity between termin ...
Temporarily engaged gear steps selection mode in the D position
To drive in temporary gear steps selection mode, operate the “-” and “+” paddle
shift switches. The gear steps can then be selected by operating the “-” and “+”
paddle shift switches. By selecting gear step using paddle shift switches, you can
control engine braking forces.
1 ...
Inspection procedure
Hint:
when the throttle position is slightly opened (the accelerator pedal
is slightly depressed) because a
floor carpet is overlapped on the accelerator pedal, or if not fully
releasing the accelerator pedal, etc.,
Dtc p505 will possibly be detected.
Read freeze frame data using the ...


