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:
On–vehicle inspection
1. Inspect air–fuel ratio compensation system
Hint:
you can also check the system by choosing ”data monitor”,
then ”o2 sensor output voltage” on the monitor of the
hand–held tester.
Connect the hand–held tester to the terminal 23 (ox1a)
@ 7 (e1) and 21 (ox1b) @ 7 (e1) of ...
Inspection procedure
1 Inspect skid control ecu connector(+bs terminal voltage)
Disconnect the skid control ecu connector.
measure the voltage between terminals +bs (2) and gnd
(1, 23) of skid control ecu harness side connector.
Voltage: 10 – 14 v
2 Reconfirm dtc
Check the dtc .
Ok :
...
Circuit description
The o/d main switch (transmission control switch) is a momentary type switch.
When pressing the o/d main
switch, the o/d off indicator light lights up and the ecm prohibits shifting
into o/d, and when pressing it
once again, the o/d off indicator light goes off and the ecm allows shifting
in ...