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:
Ecu power source circuit
Circuit description
This circuit provides power to operate the tvip ecu.
Wiring diagram
Inspection procedure
1 Check fuse (ecu–b)
Remove the fuse from the instrument panel j/b.
check the continuity of the fuse.
Standard: continuity
2 Check tvip ecu
Disconnect ...
Problem symptoms table
If a normal code is displayed during the dtc check but the problem still
occurs, check the circuits for each
problem symptom in the order given in the table below and proceed to the
relevant troubleshooting page.
Notice:
when replacing skid control ecu, sensor or etc., Turn the ignition swi ...
Precaution
1. Work precautions
(A) vehicle protection
(1) when welding, cover glass, seats, carpets, etc. With
heat resistant fireploof covers to protect them.
(B) safety
(1) never stand in the path of the chain when using a puller
on the body or frame, and be sure to attach a safety
cable.
...