Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems / Problem symptoms table
Toyota Corolla (E120): Problem symptoms table
The suspected circuits or parts for each problem symptom are shown in the table below. Use this table to troubleshoot the problem when a normal code is displayed in the diagnostic trouble code chart but the problem is still occurring. Numbers in the table indicate the order in which the circuits or parts should be checked.
Hint: when the problem is not detected by the diagnostic system even though the problem symptom is present, it may be that the problem is occurring outside the detection range of the diagnostic system.

Other materials:
Driving support system
information display
■ Driving support system
information
Select to display the operational
status of the following systems:
LTA (Lane Tracing Assist)
LDA (Lane Departure Alertl)
Dynamic radar cruise control
■ Navigation system-linked
display (if equipped)
Select to display the following
navigation system-linke ...
Brake fluid
Bleeding
Notice:
wash the brake fluid off immediately if it comes into contact with any painted
surface.
Hint:
if any work is done on the brake system or if air in the brake lines is
suspected, bleed the air from the system.
1. Fill reservoir with brake fluid
fluid: sae j1703 or fmvss no. ...
Circuit description
Refer to dtc p0120
Dtc no.
Dtc detection condition
Trouble area
P0121
The following condition is met 4 times. After the vehicle speed
has exceeded 19 mph (30 km/h) once, the throttle position
sensor output value is out of normal range when the throttle
...


