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 ...
Pressing power switch does not start system
Wiring diagram
Inspection procedure
1 Inspect radio receiver assy(+b, acc, gnd)
Check that the continuity between terminals at each
condition, as shown in the chart.
Standard:
Check that the voltage between terminals at each condition,
as shown in the chart.
Standard:
...
Do-it-yourself service precautions
If you perform maintenance by yourself, be sure to follow the correct procedure
as given in these sections.
CAUTION
The engine compartment contains many mechanisms and fluids that may move suddenly,
become hot, or become electrically energized. To avoid death or serious injury,
observe t ...


