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
1. Inspect tvip ecu
Inspect the ecu–b, dome and ecu–ig fuses.
disconnect the tvip ecu connector, and the continuity and voltage of
check each terminal of the disconnected
connector.
Standard:
If the result is not as specified, the vehicle’s side may malfunction.
Reco ...
Inspection procedure
1 Inspect fuse(ecu–ig fuse)
Remove ecu–ig fuse from the instrument panel j/b.
check continuity of ecu–ig fuse.
Ok:
continuity
2 Inspect battery
Ok:
voltage: 10 – 14 v
3 Inspect skid control ecu connector(ig1 terminal voltage)
In case of using hand–held te ...
Inspection procedure
Hint:
if dtc p0441 (purge flow), p0446 (vsv for ccv or vsv for pressure
switching valve), p0451, p0452
or p0453 is output with dtc p0442 or p0456 , first troubleshoot
dtc p0441, p0446, p0451, p0452 or p0453. If no malfunction is detected,
troubleshoot dtc
p0442 or p0456 next.
...


