Toyota Corolla Repair Manual: Catalyst system efficiency below threshold
Dtc p0420 catalyst system efficiency below threshold (bank 1)
Inspection procedure
Hint:
read freeze frame data using the hand-held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
usefu ...
Circuit description
The ecm compares the two waveforms of the heated oxygen sensors located
before and after the catalyst
to determine whether or not the catalyst performance has deteriorated.
Air–fuel ratio feedba ...
Other materials:
Inspection procedure
1 Check side squib(rh) circuit(airbag sensor assy center – front
seat airbag assy rh)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the airbag sensor
assy center and the front seat airbag assy (rh ...
Shift solenoid ”a” performance
(shift solenoid valve s1)
Dtc p0751 shift solenoid ”a” performance
(shift solenoid valve s1)
System description
The ecm uses signals from the vehicle speed sensor and crankshaft position
sensor to detect the actual
gear position (1st, 2nd, 3rd or o/d gear).
Then the ecm compares the actual gear with the shift schedu ...
Diagnostics
Preparation
Sst
09816–30010
Oil pressure switch socket
Sfi system
09843–18040
Diagnosis check wire no.2
Sfi system
supplemental restraint
system
Recomended tools
09082–00040
Toyota electrical tester
Sfi system
supplemental re ...