Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems
Toyota Corolla (E120): How to troubleshoot ecu controlled systems
- General information
- How to proceed with troubleshooting
- Customer problem analysis
- Symptom confirmation and diagnostic trouble code
- Symptom simulation
- Diagnostic trouble code chart
- Problem symptoms table
- Circuit inspection
- Electronic circuit inspection procedure
Other materials:
Circuit description
If the engine coolant temperature (ect) does not reach 75°c (167°f) despite
sufficient warm – up time has
elapsed.
Dtc no
Dtc detection condition
Trouble area
P0128
Condition (a), (b) and (c):
cold start
after engine is warmed up
& ...
Circuit description
In the diagram below, when the engine is cranked, current flows from terminal
st2 of the ignition switch to
the starter relay coil and also current flows to terminal sta of the ecm (sta
signal).
When the sta signal and ne signal are input to the ecm, tr is turned on, current
flows to the c ...
Inspection procedure
1 Inspect transmission wire(s2)
Disconnect the transmission wire connector from the
transaxle.
measure the resistance according to the value(s) in the
table below.
Standard:
2 Check harness and connector(transmission wire – ecm)
Connect the transmission connec ...