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:
Front door belt moulding assy lh
Replacement
Hint:
the installation procedures are the removal procedures in reverse
order.
Use the same procedures for the rh side and lh side.
1. Remove front armrest assy lh
2. Remove power window regulator master switch assy (w/ power window)
3. Remove front armrest base panel up ...
Have the malfunction repaired immediately. (vehicles with a smart key system)
After taking the specified steps to correct the suspected problem, check that
the warning message and light go off.
■Warning buzzer ...
Inspection procedure
1 Inspect cruise control actuator assy
Turn the ignition switch to off.
disconnect the cruise control actuator assy connector.
measure the resistance between terminals 1 (mo) and 2
(mc) of cruise control actuator assy.
Hint:
if control plate position is fully opened or ...


