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:
Malfunction in water temperature receiver gauge
Wiring diagram
Inspection procedure
1 Read value of hand–held tester
Check output value of ecm.
Connect the hand–held tester to dlc3.
Turn the ignition switch to on and push the hand–held tester main
switch on.
Select the data list mode on the hand–he ...
Manual transmission/transaxle
Preparation
Sst
Equipment
Lubricant
...
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 ...