Toyota Corolla (E120): Fail–safe chart
If any of the following codes is recorded, the ecm enters the fail–safe mode.

Check for intermittent problems
Hand–held tester only:
by putting the vehicle’s ecm in the check mode, the 1 trip detection logic is possible instead of the 2 trip detection logic, and the sensitivity to detect faults is increased. This makes it easier to detect intermittent problems.
- Clear the dtcs .
- set the check mode .
- perform a simulation test .
- check the connector and terminal .
- wiggle the harness and connector
Other materials:
On–vehicle inspection
1. Inspect air–fuel ratio compensation system
Hint:
you can also check the system by choosing ”data monitor”,
then ”o2 sensor output voltage” on the monitor of the
hand–held tester.
Connect the hand–held tester to the terminal 23 (ox1a)
@ 7 (e1) and 21 (ox1b) @ 7 (e1) of ...
On–vehicle inspection
1. Inspect drive belt
Visually check the belt for excessive wear, frayed cords,
etc.
If any defect is found, replace the drive belt.
Hint:
cracks on the rib side of a belt are considered acceptable. If the
missing chunks from the ribs are found on the belt, it should be
replaced.
2 ...
Circuit description
The rear heated oxygen sensor is used to monitor oxygen concentration in the
exhaust gas. For optimum
catalytic converter operation, the air fuel mixture must be maintained near the
ideal ”stoichiometric” ratio.
The heated oxygen sensor output voltage changes suddenly in the vicinity of ...


