Toyota Corolla (E120): Circuit description
Shifting from 1st to o/d is performed in combination with on and off of the shift solenoid valve s1 and s2 controlled by ecm. If an open or short circuit occurs in either of the solenoid valves, the ecm controls the remaining normal solenoid valve to allow the vehicle to be operated smoothly (fail safe function).
Fail safe function: if either of the solenoid valve circuits develops an open or short, the ecm turns the other solenoid valve on and off to shift to the gear positions shown in the table below. If both solenoids malfunction, hydraulic control cannot be performed electronically and must be done manually.
Manual shifting as shown in the above table must be done (in the case of a short circuit, the ecm stops sending current to the short circuited solenoid).
X: malfunctions
Monitor description
The ecm commands gearshift by turning the shift solenoid valves ”on/off”. When there is an open or short circuit in any shift solenoid valve circuit, the ecm detects the problem and the mil comes on. Illuminating the mil, the ecm performs the fail–safe and turns the other shift solenoid valves in good condition ”on/off” (in case of an open or short circuit, the ecm stops sending current to the circuit.).
Monitor strategy
Typical enabling condition
Typical malfunction thresholds
Component operating range
Wiring diagram
Other materials:
Engine assembly
Inspection
1. Inspect coolant
2. Inspect engine oil
3. Inspect battery
4. Inspect air cleaner filter element sub–assy
5. Inspect spark plug
6. Inspect fan and generator v belt
Hint:
you don’t need to check the belt deflection because auto tensioner is adopted.
7. Inspect ignition ti ...
Overhaul
1. Drain brake fluid
Notice:
wash the brake fluid off immediately if it comes into contact with any painted
surface.
2. Remove air cleaner cap sub–assy
3. Remove brake master cylinder sub–assy
disconnect the brake fluid level switch connector from
master cylinder reservoir sub ...
Inspection procedure
1 Inspect parking brake switch circuit
Check for open and short circuit in parking brake switch circuit
2 Inspect brake fluid level warning switch circuit
Check the brake fluid level in reservoir.
check for open and shot circuit in brake fluid level warning
switch circuit
...