SFI SYSTEM, Diagnostic DTC:P042000
| DTC Code | DTC Name |
|---|---|
| P042000 | Catalyst System Efficiency Below Threshold Bank 1 |
MONITOR DESCRIPTION
The ECM uses air fuel ratio sensors mounted in front of and behind the Three-Way Catalytic Converter (TWC) to monitor its efficiency.
The first sensor, the air fuel ratio sensor (sensor 1), sends pre-catalyst information to the ECM. The second sensor, the air fuel ratio sensor (sensor 2), sends post-catalyst information to the ECM.
In order to detect any deterioration in the three-way catalytic converter, the ECM calculates the oxygen storage capacity of the three-way catalytic converter. This calculation is based on the output current of the air fuel ratio sensor (sensor 2) while performing active air fuel ratio control.
The oxygen storage capacity value is an indication of the oxygen storage capacity of the three-way catalytic converter. When the vehicle is being driven with a warm engine, active air fuel ratio control is performed for approximately 30 seconds. When it is performed, the ECM deliberately sets the air fuel ratio to lean or rich levels. If the cycle of the waveform for the air fuel ratio sensor (sensor 2) is long, the oxygen storage capacity is great. There is a direct correlation between the air fuel ratio sensor (sensor 2) and the oxygen storage capacity of the three-way catalytic converter.
The ECM uses the oxygen storage capacity value to determine the state of the three-way catalytic converter. If any deterioration has occurred, the ECM will illuminate the MIL and store a DTC.
This system determines the deterioration of the entire catalyst system (including the front and rear catalysts), by using the oxygen storage capacity value of the front catalyst, that is more sensitive than the rear catalyst, as the representative value. Therefore, be sure to replace the front and rear catalysts together when catalyst replacement is necessary.
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
MIL |
Memory |
Note |
|---|---|---|---|---|---|---|
P042000 |
Catalyst System Efficiency Below Threshold Bank 1 |
The oxygen storage capacity value is less than the standard value under active air fuel ratio control (2 trip detection logic). |
|
Comes on |
DTC stored |
SAE Code: P0420 |
CATALYST LOCATION
*A |
for Hatchback |
- |
- |
*1 |
Exhaust Manifold Converter Sub-assembly |
*2 |
Front Exhaust Pipe Assembly |
*3 |
Tail Exhaust Pipe Assembly |
*4 |
Air Fuel Ratio Sensor (Sensor 1) |
*5 |
Air Fuel Ratio Sensor (Sensor 2) |
- |
- |
*A |
for Wagon |
- |
- |
*1 |
Exhaust Manifold Converter Sub-assembly |
*2 |
Front Exhaust Pipe Assembly |
*3 |
Tail Exhaust Pipe Assembly |
*4 |
Air Fuel Ratio Sensor (Sensor 1) |
*5 |
Air Fuel Ratio Sensor (Sensor 2) |
- |
- |
Replace the exhaust manifold converter sub-assembly (*1) and the front exhaust pipe assembly (*2) together when catalyst replacement is necessary. (Excluding air fuel ratio sensor (sensor 1)*4 and air fuel ratio sensor (sensor 2)*5)
MONITOR STRATEGY
Required Sensors/Components (Main) |
Air fuel ratio sensor (sensor 1) Air fuel ratio sensor (sensor 2) |
Required Sensors/Components (Related) |
Intake air temperature sensor (mass air flow meter sub-assembly) Mass air flow meter sub-assembly Crankshaft position sensor Engine coolant temperature sensor |
Frequency of Operation |
Once per driving cycle |
TYPICAL ENABLING CONDITIONS
Battery voltage |
11 V or higher |
Intake air temperature |
-10°C (14°F) or higher |
Engine coolant temperature |
75°C (167°F) or higher |
Atmospheric pressure |
76 kPa(abs) [11.02 psi(abs)] or higher |
Idling |
Off |
Engine speed |
Less than 4000 rpm |
Air fuel ratio sensor (sensor 1) status |
Activated |
Fuel system status |
Closed loop |
Engine load |
10% or higher, and less than 140% |
All of the following conditions are met |
- |
Mass air flow rate |
6.0 to 40 gm/sec. |
Front catalyst temperature (estimated) |
570°C (1058°F) to 800°C (1472°F) |
Rear catalyst temperature (estimated) |
460°C (860°F) to 700°C (1292°F) |
CONFIRMATION DRIVING PATTERN
It is necessary for the response of the air fuel ratio sensor (sensor 2) to be normal in order to confirm DTC P042000. Therefore, perform the confirmation driving pattern for the air fuel ratio sensor (sensor 2) monitor before performing the confirmation driving pattern for the catalyst efficiency monitor.
Performing this confirmation driving pattern will activate the catalyst efficiency monitor. This is very useful for verifying the completion of a repair.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher [A].
Tip:In order to keep the idle stable, turn the A/C and all other electric loads off and do not perform any shift operations.
Drive the vehicle at approximately 60 km/h (37 mph) for 10 minutes or more [B].
CAUTION:When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Tip:Drive the vehicle while keeping the engine load as constant as possible.
Turn the ignition switch off and wait for at least 30 seconds [C].
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher [D].
Drive the vehicle at approximately 60 km/h (37 mph) for 10 minutes or more [E].
CAUTION:When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Tip:Drive the vehicle while keeping the engine load as constant as possible.
Enter the following menus: Powertrain / Engine / Trouble Codes [F].
Read the pending DTCs.
Tip:If a pending DTC is output, the system is malfunctioning.
If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P042000.
Check the DTC judgment result.
GTS Display
Description
NORMAL
DTC judgment completed
System normal
ABNORMAL
DTC judgment completed
System abnormal
INCOMPLETE
DTC judgment not completed
Perform driving pattern after confirming DTC enabling conditions
Tip:If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result is INCOMPLETE, perform the following procedure.
Drive the vehicle at a speed between 75 and 100 km/h (47 and 62 mph) for 10 minutes or more [G].
CAUTION:When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Tip:Drive the vehicle while keeping the engine load as constant as possible.
Enter the following menus: Powertrain / Engine / Trouble Codes [H].
Read the pending DTCs.
Tip:If a pending DTC is output, the system is malfunctioning.
If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P042000.
Check the DTC judgment result.
GTS Display
Description
NORMAL
DTC judgment completed
System normal
ABNORMAL
DTC judgment completed
System abnormal
INCOMPLETE
DTC judgment not completed
Perform driving pattern after confirming DTC enabling conditions
Tip:If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
CAUTION / NOTICE / HINT
If a malfunction cannot be found when troubleshooting DTC P042000, a lean or rich abnormality may be the cause. Perform troubleshooting by following the inspection procedure for P017100 (System Too Lean) and P017200 (System Too Rich).
Sensor 1 refers to the sensor closest to the engine assembly.
Sensor 2 refers to the sensor farthest away from the engine assembly.
Read Freeze Frame Data using the GTS. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. When troubleshooting, Freeze Frame Data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P042000)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Read the DTCs.
Powertrain > Engine > Trouble Codes
Result
Result
Proceed to
DTC P042000 is output
A
DTC P042000 and other DTCs are output
B
Tip:If any DTCs other than P042000 are output, troubleshoot those DTCs first.
PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Warm up the air fuel ratio sensors at an engine speed of 2500 rpm for 90 seconds.
Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor / Data List / Coolant Temperature, A/F (O2) Sensor Voltage B1S1 and A/F (O2) Sensor Current B1S2.
Powertrain > Engine > Active Test
Active Test Display
Control the Injection Volume for A/F Sensor
Data List Display
Coolant Temperature
A/F (O2) Sensor Voltage B1S1
A/F (O2) Sensor Current B1S2
Perform the Control the Injection Volume for A/F Sensor operation with the engine idling.
Monitor the output values of the air fuel ratio sensors (A/F (O2) Sensor Voltage B1S1 and A/F (O2) Sensor Current B1S2) displayed on the GTS.
Tip:The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%.
The air fuel ratio sensor (sensor 1) has an output delay of a few seconds and the air fuel ratio sensor (sensor 2) has a maximum output delay of approximately 20 seconds.
If the sensor output value does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.
Standard
GTS Display (Sensor)
Injection Volume
Status
Value
A/F (O2) Sensor Voltage B1S1
(Air fuel ratio sensor (sensor 1))
12.5%
Rich
Below 3.1 V
-12.5%
Lean
Higher than 3.4 V
A/F (O2) Sensor Current B1S2
(Air fuel ratio sensor (sensor 2))
12.5%
Rich
Below -0.86 mA
-12.5%
Lean
More than 0.33 mA
Result
Status of A/F (O2) Sensor Voltage B1S1
Status of A/F (O2) Sensor Current B1S2
Air Fuel Ratio Condition and Air Fuel Ratio Sensors Condition
Main Suspected Trouble Area
Proceed to
Lean/Rich
Lean/Rich
Normal
Three-way catalytic converter
Gas leak from exhaust system
A
Lean
Lean/Rich
Air fuel ratio sensor (sensor 1) malfunction
Air fuel ratio sensor (sensor 1)
B
Rich
Lean/Rich
Air fuel ratio sensor (sensor 1) malfunction
Air fuel ratio sensor (sensor 1)
Lean/Rich
Lean
Air fuel ratio sensor (sensor 2) malfunction
Air fuel ratio sensor (sensor 2)
Gas leak from exhaust system
C
Lean/Rich
Rich
Air fuel ratio sensor (sensor 2) malfunction
Air fuel ratio sensor (sensor 2)
Gas leak from exhaust system
Lean
Lean
Actual air fuel ratio lean
Extremely lean actual air fuel ratio
Gas leak from exhaust system
D
Rich
Rich
Actual air fuel ratio rich
Extremely rich actual air fuel ratio
Gas leak from exhaust system
Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output voltage (A/F (O2) Sensor Voltage B1S1) is consistently higher than 3.4 V, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently more than 0.33 mA.
Rich: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output voltage (A/F (O2) Sensor Voltage B1S1) is consistently below 3.1 V, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently below -0.86 mA.
Lean/Rich: During the Control the Injection Volume for A/F Sensor Active Test, the output value of the air fuel ratio sensor (sensor 1) or air fuel ratio sensor (sensor 2) alternate correctly.
Tip:Refer to "Data List / Active Test" [A/F (O2) Sensor Voltage B1S1, A/F (O2) Sensor Current B1S2].
B REPLACE AIR FUEL RATIO SENSOR (SENSOR 1)Click here
C CHECK FOR EXHAUST GAS LEAKClick here
D CHECK FOR EXHAUST GAS LEAKClick here
CHECK FOR EXHAUST GAS LEAK
Check for exhaust gas leaks.
OK
No gas leaks in exhaust system.
Result
Proceed to
OK
NG
OK REPLACE EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY AND FRONT EXHAUST PIPE ASSEMBLYClick here
NG REPAIR OR REPLACE EXHAUST SYSTEMClick here
REPLACE AIR FUEL RATIO SENSOR (SENSOR 1)
Replace the air fuel ratio sensor (sensor 1).
Tip:Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 1).
Result
Proceed to
NEXT
NEXT CHECK WHETHER DTC OUTPUT RECURS (DTC P042000)Click here
CHECK FOR EXHAUST GAS LEAK
Check for exhaust gas leaks.
OK
No gas leaks in exhaust system.
Result
Proceed to
OK
NG
NG REPAIR OR REPLACE EXHAUST SYSTEMClick here
REPLACE AIR FUEL RATIO SENSOR (SENSOR 2)
Replace the air fuel ratio sensor (sensor 2).
Tip:Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 2).
Result
Proceed to
NEXT
NEXT CHECK WHETHER DTC OUTPUT RECURS (DTC P042000)Click here
CHECK FOR EXHAUST GAS LEAK
Check for exhaust gas leaks.
OK
No gas leaks in exhaust system.
Result
Proceed to
OK
NG
NG REPAIR OR REPLACE EXHAUST SYSTEMClick here
CHECK CAUSE OF EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO
Check the cause of extremely rich or lean actual air fuel ratio, referring to the DTC P017100 and P017200 Inspection Procedure.
Result
Proceed to
NEXT
NEXT CHECK WHETHER DTC OUTPUT RECURS (DTC P042000)Click here
REPAIR OR REPLACE EXHAUST SYSTEM
Repair or replace exhaust system.
Result
Proceed to
NEXT
CLEAR DTC
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs.
Powertrain > Engine > Clear DTCs
Turn the ignition switch off and wait for at least 30 seconds.
Result
Proceed to
NEXT
CHECK WHETHER DTC OUTPUT RECURS (DTC P042000)
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Read the DTCs.
Powertrain > Engine > Trouble Codes
Result
Result
Proceed to
DTCs are not output
A
DTC P042000 is output
B
A END
REPLACE EXHAUST MANIFOLD CONVERTER SUB-ASSEMBLY AND FRONT EXHAUST PIPE ASSEMBLY
Note:When replacing the exhaust manifold converter sub-assembly and the front exhaust pipe assembly in order to replace the three-way catalytic converter, it is not necessary to replace the air fuel ratio sensor (sensor 1) and the air fuel ratio sensor (sensor 2).
Tip:Confirm the replacement parts, referring to the illustration in Catalyst Location.
Replace the exhaust manifold converter sub-assembly.
Replace the front exhaust pipe assembly.
Result
Proceed to
NEXT
NEXT END