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:
Inspection procedure
1 Prepare for inspection
Disconnect the negative (–) terminal cable from the battery, and wait at
least for 90 seconds.
remove the horn button assy .
disconnect the connector of the instrument panel passenger airbag assy
.
disconnect the connector of the front sea ...
Sound quality is bad only when cd is played(volume is
too low)
Inspection procedure
1 Replace cd with another and recheck
Replace the cd with another and recheck.
Check the installation condition of the radio receiver assembly.
Standard: malfunction disappear.
Check and replace radio receiver assy ...
Inspection procedure
Hint:
if dtc p0441 (purge flow), p0446 (vsv for ccv or vsv for pressure
switching valve), p0451, p0452
or p0453 is output with dtc p0442 or p0456 , first troubleshoot
dtc p0441, p0446, p0451, p0452 or p0453. If no malfunction is detected,
troubleshoot dtc
p0442 or p0456 next.
...


