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:
Turning on light switch does not light up night time
illumination of radio receiver
Wiring diagram
Inspection procedure
1 Inspect radio receiver assy(ill+, ill–)
Check that the voltage between terminals at each condition,
as shown in the chart.
Standard:
Repair or replace harness or connector ...
On–vehicle inspection
1. Check cooling fan operation with low temperature (below 83 c (181 f))
Turn the ignition switch on.
check that the cooling fan stops.
Hint:
if not, check the cooling fan relay and water temperature sensor, and check for
separated connector or severed
wire between the cooling fan ...
Circuit description
Refer to dtc p0130
Hint:
the ecm provides a pulse width modulated control circuit to adjust current
through the heater. The heated
oxygen sensor heater circuit uses a relay on the b+ side of the circuit.
Monitor description
The ecm uses the heated oxygen sensor information to regulate t ...