P0420
Three Way Catalytic Converter. Malfunction.
Fault symptoms
- Market US/CA: CHECK ENGINE.
On-Board Diagnostics
Type of diagnosis:
- Once per driving cycle. Interrupted when fault criteria fulfilled or OK reported. Restarts next driving cycle.
Enable criteria:
- General condition for this diagnostic trouble code: Atmospheric pressure must exceed 72 kPa as well as coolant and intake air temperature must exceed -7 °C.
- Ignition of front catalyst: Engine running. Air mass flow has exceeded 5 g/s (aut 7 g/s) for an accumulate time of 120 sec. The air mass flow has exceeded 20 g/s for an accumulate time of 18 sec. No motor braking with fuel shut-off for more than 10 sec. No idling longer than 40 sec.
Assessment of catalytic converter: Longer than 200 sec. since start. Coolant temperature above 70 °C. Vehicle speed 40-115 km/h. Accelerator pedal depressed. Engine speed 1270-2540 rpm (auto. 1200-2100 rpm). Engine load 100-500 mg/c. Oxygen sensor 2 voltage changes corrected with respect to load and engine speed and accumulated for approved voltage periods for oxygen sensor 1*) When the voltage changes have been corrected and accumulated for 20 sec., their average value is calculated.
*) Accepted periods have 30-80 % pulse ratio (+trigger).
Fault criteria:
- Mean value of voltage transitions exceeding a calibrated value.
Dependents:
- P0100, P0102, P0103, P0116, P0117, P0118, P0131, P0132, P0134, P0138, P0140, P0336, P0337, P0501, P0502, All throttle faults.
System reaction to a fault:
- None.
OK report:
- Diagnosis performed once and fault criteria not fulfilled.
Fault handling: Fault Handling III, Other Emission-Related Component & Function
- Type III.
Diagnostic help
The capacity of the catalyst can be reduced temporarily or permanently for the following reason
- Lead or sulphur in the fuel.
- Fuel additives.
- Engine oil additives.
Functions in the diagnostic tool related to the fault:
- Diagnostic status for the diagnosis.
For information, Tech 2 Menu Structure, DTC Menu, Read Value, Activate, Sys Info