Toyota Corolla (E120): System description
The ecm uses signals from the vehicle speed sensor and crankshaft position sensor to detect the actual gear position (1st, 2nd, 3rd or o/d gear).
Then the ecm compares the actual gear with the shift schedule in the ecm memory to detect the mechanical trouble of the shift solenoid valves, the valve body or automatic transaxle (clutch, brake or gear etc.).

Monitor description
The ecm commands gear shifts by turning the shift solenoid valves ”on/off”. According to the input shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ecm detects the actual gear position (1st, 2nd, 3rd or o/d gear position). When the gear position commanded by the ecm and the actual gear position are not same, the ecm illuminates the mil.
Monitor strategy

Typical enabling conditions





Typical malfunction thresholds



Typical malfunction thresholds



Other materials:
Overhaul
1. Remove roof headlining assy
2. Remove sliding roof glass sub–assy
using a torx wrench (t25), remove the 4 screws the sliding roof
glass.
pull the glass upward to remove it.
3. Remove sliding roof weatherstrip
4. Remove sliding roof drive gear sub–assy
Notice:
...
Antenna cord sub–assy
Replacement
Hint: components:
1. Remove instrument panel sub–assy upper
Hint:
refer to the procedure until the step, ”remove instrument panel sub–assy
upper” of
instrument panel sub–assy lower.
Remove the related parts as long as the antenna cord sub–assy can be
removed ...
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
...


