Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / ABS with EBD system / Brake warning light circuit / Circuit description
Toyota Corolla (E120): Circuit description
If the ecu detects trouble, it lights the brake warning light at the same time of prohibiting abs control. At this time, the ecu records a dtc in memory.
Connect terminals tc and cg of the dlc3 to make the brake warning light blink and output the dtc.
Wiring diagram

Other materials:
Circuit description
The rear heated oxygen sensor is used to monitor oxygen concentration in the
exhaust gas. For optimum
catalytic converter operation, the air fuel mixture must be maintained near the
ideal ”stoichiometric” ratio.
The heated oxygen sensor output voltage changes suddenly in the vicinity of ...
How to proceed with troubleshooting
1 Vehicle brought in
2 Customer problem analysis check and symptom check
3 Problem symptoms table
Without applicable symptoms, proceed to ”a”
with applicable symptoms, proceed to ”b”
4 Perform troubleshooting in the following method, depending on
malfunction symptom ...
Circuit description
Monitor description
The ecm commands gearshift by turning the shift solenoid valves ”on/off”.
When there is an open or short
circuit in any shift solenoid valve circuit, the ecm detects the problem and the
mil comes on. Illuminating
the mil, the ecm performs the fail–safe and turns ...


