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:
Engine coolant
The coolant level is satisfactory if it is between the “F” and “L” lines on the
reservoir when the engine is cold.
1 Reservoir cap
2 “F” line
3 “L” line
If the level is on or below the “L” line, add coolant up to the “F” line.
■Coolant selection
Only use “To ...
Inspection procedure
Hint:
if different dtcs related to different systems that have terminal e2
as the ground terminal are output
simultaneously, terminal e2 may be open.
If dtc p0441 (purge flow), p0446 (vsv for ccv), p0451, p0452 or p0453
(evaporative pressure
sensor) is output with dtc p0442 or p0456, ...
Basic inspection
Resistance measuring condition of electronic parts
unless stated, all resistance is measured at an ambient
temperature of 20 c (68 °F). As the resistance
may be outside the specifications if measured at high temperatures
immediately after
the vehicle has been running, measu ...


