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
When a misfire occurs in the engine, hydrocarbons (hc) enter the exhaust in
high concentrations. If this hc
concentration is high enough, there could be an increase in exhaust emissions
levels. High concentrations
of hc passing through the catalyst also cause to temperature of the catalyst to ...
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 ...
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 ...


