P0420 Three way catalyst function
DTC Logic
DTC DETECTION LOGIC
The ECM monitors the switching frequency ratio of air fuel ratio (A/F)
sensor 1 and heated oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage c ...
Power supply and ground circuit
Diagnosis Procedure
1.CHECK FUSE
Check that the following fuse is not fusing.
Is the fuse fusing?
YES >> Replace the fuse after repairing the applicable circuit.
NO >> GO TO 2.
2.CHECK GROUND CONNECTION
Turn ignition switch OFF
Check ground connection E9 and E15. Refer ...
P1572 ASCD Brake switch
DTC Logic
DTC DETECTION LOGIC
NOTE:
If DTC P1572 is displayed with DTC P0605, first perform the trouble
diagnosis for DTC P0605. Refer
to EC-348, "DTC Logic".
This self-diagnosis has the one trip detection logic. When
malfunction A is detected, DTC is not
stored in ECM me ...