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:
Inspection procedure
1 Check d squib circuit(airbag sensor assy center – horn button
assy)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the airbag sensor
assy center and the horn button assy.
for the oran ...
Circuit description
The variable valve timing (vvt) system includes the ecm, the oil control
valve (ocv) and the vvt controller.
The ecm sends a target ”duty–cycle” control signal to the ocv. This control
signal, applied to the ocv,
regulates the oil pressure supplied to the vvt controller. Camshaft timin ...
Inspection procedure
1 Check operation(overdrive)
Drive the vehicle after the engine warms up.
check that overdrive on e off occurs by an operation of the o/d
switch on–off.
2 Inspect terminal voltage(od)
Remove the cruise control ecu assy with the connector
still connected.
tur ...


