Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Catalyst system efficiency below
threshold
Toyota Corolla (E120): Catalyst system efficiency below threshold
Dtc p0420 catalyst system efficiency below threshold (bank 1)
Other materials:
Terminals of ecu
Oscilloscope wave (*1)
Hint:
terminal: od – gnd
gauge set: 5 v / div, 50 ms / div
condition: during cruise control driving o/d switch on.
...
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 ...
Installing tire pressure
warning valves and transmitters
(vehicles with a
tire pressure warning system)
When replacing tires or wheels,
tire pressure warning valves and transmitters must also be
installed.
When new tire pressure warning
valves and transmitters are
installed, new ID codes must be
registered in the tire pressure
warning computer and the tire
pressure warning system must
be initialized. ...


