MONITOR DESCRIPTION
The ECM uses 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, sends pre-catalyst information to the ECM. The second sensor, the heated oxygen sensor, 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 voltage output of the heated oxygen sensor 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 heated oxygen sensor is long, the oxygen storage capacity is great. There is a direct correlation between the heated oxygen sensor 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 (1 trip detection logic). |
| Comes on | DTC stored | SAE Code: P0420 |
P043000 | Catalyst System Efficiency Below Threshold Bank 2 | The oxygen storage capacity value is less than the standard value under active air fuel ratio control (1 trip detection logic). |
| Comes on | DTC stored | SAE Code: P0430 |
CATALYST LOCATION
*1 | Air Fuel Ratio Sensor (Bank 1 Sensor 1) | *2 | Air Fuel Ratio Sensor (Bank 2 Sensor 1) |
*3 | Heated Oxygen Sensor (Bank 2 Sensor 2) | *4 | Heated Oxygen Sensor (Bank 1 Sensor 2) |
*5 | TWC: Front Catalyst | *6 | TWC: Rear Catalyst |
*7 | Center Exhaust Pipe Assembly | *8 | Tail Exhaust Pipe Assembly |
*9 | Tail Exhaust Pipe Assembly LH | *10 | Exhaust Manifold |
*11 | Exhaust Manifold LH | *12 | Front Exhaust Pipe Assembly |
NOTICE:
MONITOR STRATEGY
Related DTCs | P0420: Catalyst deterioration (bank 1) P0430: Catalyst deterioration (bank 2) |
Required Sensors/Components (Main) | Air fuel ratio sensor Heated oxygen sensor |
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 |
Duration | Approximately 30 seconds |
MIL Operation | 2 driving cycles |
Sequence of Operation | None |
TYPICAL ENABLING CONDITIONS
Monitor runs whenever the following DTCs are not stored | P0010, P0020 (VVT oil control solenoid bank 1, 2) P0011, P0021 (VVT system bank 1, 2 - advance) P0012, P0022 (VVT system bank 1, 2 - retard) P0013, P0023 (Exhaust VVT oil control solenoid bank 1, 2) P0014, P0024 (Exhaust VVT system bank 1, 2 - advance) P0015, P0025 (Exhaust VVT system bank 1, 2 - retard) P0016, P0018 (VVT system bank 1, 2 - misalignment) P0017, P0019 (Exhaust VVT system bank 1, 2 - misalignment) P0031, P0032, P0051, P0052, P101D, P103D (Air fuel ratio sensor heater) P0037, P0038, P0057, P0058, P0141, P0161, P102D, P105D (Heated oxygen sensor heater) P0087, P0088, P0191, P0192, P0193 (Fuel pressure sensor (for high pressure side)) P0101, P0102, P0103 (Mass air flow meter) P0111, P0112, P0113 (Intake air temperature sensor) P0116, P0117, P0118 (Engine coolant temperature sensor) P011B (Engine coolant temperature/intake air temperature sensor correlation) P0121, P0122, P0123, P0222, P0223, P2135 (Throttle position sensor) P0125 (Insufficient coolant temperature for closed loop fuel control) P0128 (Thermostat) P0136, P0137, P0138, P0139, P013A, P013C, P0156, P0157, P0158, P0159, P0607 (Heated oxygen sensor) P014C, P014D, P014E, P014F, P015A, P015B, P015C, P015D, P2195, P2196, P2197, P2198, P2237, P2238, P2239, P2240, P2241, P2242, P2252, P2253, P2255, P2256 (Air fuel ratio sensor) P0171, P0172, P0174, P0175 (Fuel system) P0201, P0202, P0203, P0204, P0205, P0206, P062D, P21CF, P21D0, P21D1, P21D2, P21D3, P21D4 (Fuel injector) P0300 - P0306 (Misfire) P0327, P0328, P0332, P0333 (Knock control sensor) P0335, P0337, P0338 (Crankshaft position sensor) P0340, P0342, P0343, P0345, P0347, P0348 (Camshaft position sensor) P0351 - P0356 (Igniter) P0365, P0367, P0368, P0390, P0392, P0393 (Exhaust camshaft position sensor) P0500 (Vehicle speed sensor) P0657, P2102, P2103, P2111, P2112, P2119 (Throttle actuator) P107B, P107C, P107D (Fuel pressure sensor (for low pressure side)) P11EA, P11EB, P11EC, P11ED, P11EE, P11EF, P11F0, P11F1, P219A, P219B, P219C, P219D, P219E, P219F, P21A0, P21A1 (Air-fuel ratio imbalance) P1235 (High pressure fuel pump circuit) |
Response rate during fuel cut from rich condition | Completed |
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 3500 rpm |
Air fuel ratio sensor status | Activated |
Fuel system status | Closed loop |
Engine load | 10% or higher, and less than 100% |
Shift position | 3rd or higher |
All of the following conditions are met | 1, 2 and 3 |
1. Mass air flow rate | 5 gm/sec. or higher, and less than 95 gm/sec. |
2. Front catalyst temperature (estimated) | 580°C (1076°F) or higher, and less than 820°C (1508°F) |
3. Rear catalyst temperature (estimated) | 340°C (644°F) or higher, and less than 820°C (1508°F) |
TYPICAL MALFUNCTION THRESHOLDS
Oxygen Storage Capacity (OSC) of catalyst (Normalized) | Less than 1 |
MONITOR RESULT
Refer to detailed information in Checking Monitor Status.
Click here
P0420: Catalyst Efficiency / O2 STORAGE B1 Monitor ID | Test ID | Scaling | Unit | Description |
---|---|---|---|---|
$21 | $AF | Multiply by 0.001 | No dimension | Oxygen storage capacity of catalyst bank 1 (Normalization) |
Monitor ID | Test ID | Scaling | Unit | Description |
---|---|---|---|---|
$22 | $AF | Multiply by 0.001 | No dimension | Oxygen storage capacity of catalyst bank 2 (Normalization) |
CONFIRMATION DRIVING PATTERN
HINT:
Click here
Click here
HINT:
In order to keep the idle stable, turn the A/C and all other electric loads off and do not perform any shift operations.
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
HINT:
Drive the vehicle while keeping the engine load as constant as possible.
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
HINT:
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
HINT:
HINT:
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
HINT:
HINT:
If the monitor item does not change to Complete, and no DTCs are stored, extend the driving time.
Techstream Display | Description |
---|---|
NORMAL |
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ABNORMAL |
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INCOMPLETE |
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HINT:
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
CONDITIONING FOR SENSOR TESTING
HINT:
Perform the operation with the engine speeds and time durations described below prior to checking the waveforms of the air fuel ratio and heated oxygen sensors. This is to activate the sensors sufficiently to obtain appropriate inspection results.
HINT:
CAUTION / NOTICE / HINT
HINT:
*: The No. 1 cylinder is the cylinder which is farthest from the transaxle.
PROCEDURE
1. | CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P042000 AND/OR P043000) |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Powertrain > Engine > Trouble Codes Result | Proceed to |
---|---|
DTC P042000 and/or P043000 are output | A |
DTC P042000 and/or P043000 and other DTCs are output | B |
HINT:
If any DTCs other than P042000 and/or P043000 are output, troubleshoot those DTCs first.
B | GO TO DTC CHART |
|
2. | PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE INJECTION VOLUME FOR A/F SENSOR) |
(a) Connect the Techstream to the DLC3.
(b) Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.
(c) Turn the Techstream on.
(d) Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for approximately 90 seconds.
(e) 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 O2 Sensor Voltage B1S2 or A/F (O2) Sensor Voltage B2S1 and O2 Sensor Voltage B2S2.
Powertrain > Engine > Active Test Active Test Display |
---|
Control the Injection Volume for A/F Sensor |
Data List Display |
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Coolant Temperature |
A/F (O2) Sensor Voltage B1S1 |
A/F (O2) Sensor Voltage B2S1 |
O2 Sensor Voltage B1S2 |
O2 Sensor Voltage B2S2 |
(f) Perform the Active Test operation with the engine idling (change the fuel injection volume).
(g) Monitor the voltage outputs of the air fuel ratio sensor and heated oxygen sensor (A/F (O2) Sensor Voltage B1S1 and O2 Sensor Voltage B1S2 or A/F (O2) Sensor Voltage B2S1 and O2 Sensor Voltage B2S2) displayed on the Techstream.
HINT:
Standard:
Techstream Display (Sensor) | Injection Volume | Status | Voltage |
---|---|---|---|
A/F (O2) Sensor Voltage B1S1 A/F (O2) Sensor Voltage B2S1 (Air fuel ratio) | 12.5% | Rich | Below 3.1 V |
-12.5% | Lean | Higher than 3.4 V | |
O2 Sensor Voltage B1S2 O2 Sensor Voltage B2S2 (Heated oxygen) | 12.5% | Rich | Higher than 0.55 V |
-12.5% | Lean | Below 0.4 V |
Status of A/F (O2) Sensor Voltage B1S1 or A/F (O2) Sensor Voltage B2S1 | Status of O2 Sensor Voltage B1S2 or O2 Sensor Voltage B2S2 | Actual air fuel ratio, air fuel ratio sensor and heated oxygen sensor condition | Misfire | Main Suspected Trouble Area | Proceed to |
---|---|---|---|---|---|
Lean/Rich | Lean/Rich | Normal | - |
| A |
Lean | Lean/Rich | Air fuel ratio sensor malfunction | - |
| B |
Rich | Lean/Rich | Air fuel ratio sensor malfunction | - |
| |
Lean/Rich | Lean | Heated oxygen sensor malfunction | - |
| C |
Lean/Rich | Rich | Heated oxygen sensor malfunction | - |
| |
Lean | Lean | Actual air fuel ratio lean | May occur |
| D |
Rich | Rich | Actual air fuel ratio rich | - |
|
B | GO TO STEP 4 |
C | GO TO STEP 5 |
D | GO TO STEP 7 |
|
3. | CHECK FOR EXHAUST GAS LEAK |
(a) Check for exhaust gas leaks.
OK:
No gas leaks in exhaust system.
OK | GO TO STEP 10 |
NG | GO TO STEP 9 |
4. | REPLACE AIR FUEL RATIO SENSOR |
(a) Replace the air fuel ratio sensor.
Click here
HINT:
Perform "Inspection After Repair" after replacing the air fuel ratio sensor.
Click here
NEXT | GO TO STEP 10 |
5. | CHECK FOR EXHAUST GAS LEAK |
(a) Check for exhaust gas leaks.
OK:
No gas leaks in exhaust system.
NG | GO TO STEP 9 |
|
6. | REPLACE HEATED OXYGEN SENSOR |
(a) Replace the heated oxygen sensor.
Click here
HINT:
Perform "Inspection After Repair" after replacing the heated oxygen sensor.
Click here
NEXT | GO TO STEP 10 |
7. | CHECK FOR EXHAUST GAS LEAK |
(a) Check the exhaust gas leaks.
OK:
No gas leaks in exhaust system.
NG | GO TO STEP 9 |
|
8. | CHECK CAUSE OF EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO |
(a) Check the cause of extremely rich or lean actual air fuel ratio, referring to the DTC P017100 Inspection Procedure.
Click here
NEXT | GO TO STEP 10 |
9. | REPAIR OR REPLACE EXHAUST SYSTEM |
(a) Repair or replace exhaust system.
HINT:
Perform "Inspection After Repair" after repairing or replacing the exhaust system.
Click here
|
10. | CLEAR DTC |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Clear the DTC.
Powertrain > Engine > Clear DTCs(e) Turn the engine switch off and wait for at least 30 seconds.
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11. | CHECK WHETHER DTC OUTPUT RECURS (DTC P042000 AND/OR P043000) |
(a) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
(b) Enter the following menus: Powertrain / Engine / Trouble Codes.
(c) Read the DTCs.
Powertrain > Engine > Trouble Codes Result | Proceed to |
---|---|
DTCs are not output (No pending DTCs output) | A |
DTC P042000 and/or P043000 are output | B |
A | END |
|
12. | CHECK DTC OUTPUT (DTC P042000 AND/OR P043000) |
NOTICE:
HINT:
Confirm the replacement parts, referring to the illustration in Catalyst Location.
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Powertrain > Engine > Trouble Codes Result | Proceed to |
---|---|
DTC P042000 is output | A |
DTC P043000 is output | B |
DTC P042000 and P043000 are output | C |
A | REPLACE EXHAUST MANIFOLD (TWC: FRONT CATALYST) AND FRONT EXHAUST PIPE ASSEMBLY (TWC: REAR CATALYST) |
B | REPLACE EXHAUST MANIFOLD ASSEMBLY LH (TWC: FRONT CATALYST) AND FRONT EXHAUST PIPE ASSEMBLY (TWC: REAR CATALYST) |
C | REPLACE EXHAUST MANIFOLD (TWC: FRONT CATALYST), EXHAUST MANIFOLD ASSEMBLY LH (TWC: FRONT CATALYST) AND FRONT EXHAUST PIPE ASSEMBLY (TWC: REAR CATALYST) |