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:
Torque converter clutch and drive plate (atm)
Inspection
1. Inspect torque converter clutch assy
Inspect the one–way clutch.
Set sst into the inner race of the one–way clutch.
Sst 09350–32014 (09351–32010)
set sst so that it fits in the notch of the converter
hub and outer race of the one–way clutch.
...
How to proceed with troubleshooting
Hint:
carry out troubleshooting in accordance with the procedures on the following
page. Here, only the basic
procedures are shown. Details are provided in the diagnostics section, showing
the most effective methods
for each circuit. Confirm the troubleshooting procedures first for the releva ...
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 schedule in the ecm memory
to detect the mechanical
trouble of the shift solenoid valves, th ...