A 3-way catalytic converter (TWC) controls emissions by converting hydrocarbons (HC) and carbon monoxide (CO) into carbon dioxide (CO2), and oxides of nitrogen (NOx) into nitrogen. The 3-way catalytic converter also stores oxygen. When the listed
idle conditions follow the listed driving conditions, the Catalyst System Efficiency test will run. The engine control module (ECM) monitors this oxygen storage capacity by comparing the pre and post-catalyst oxygen sensor signals while adding and subtracting
fuel during specific idle conditions. The ECM compares the pre-catalyst and post-catalyst oxygen sensor signals to determine if the oxygen storage capacity of the catalyst is degraded.
- Driving Condition
DTCs P0010, P0011, P0013, P0014, P0016, P0017, P0018, P0019, P0030, P0036, P0053, P0054, P0059, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128,
P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0151- P0155, P0171, P0172, P0174, P0175, P0201-P0208, P0220, P0222, P0223, P0315, P0300, P0301-P0308, P0335, P0336, P0340, P0341, P0345, P0346, P0351-P0358, P0401, P0403, P0404, P0405, P0406, P0442,
P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0455, P0496, P0506, P0507, P060D, P1101, P1133, P1153, P1174, P1175, P1258, P1400, P1404, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176,P2A00, P2A01, P2A03 or U0107 are not
set.
- Idle Condition
• | The Throttle Position (TP) is less than 2.0 percent |
• | The vehicle speed is less than the specified value. |
• | The vehicle is driven at more than 1,000 RPM for more than 20 seconds since the last idling. |
• | The engine run time is greater than specified time. |
• | This diagnostic attempts one test during each valid idle period when the above conditions have been met. This test attempts up to 17 times during each drive cycle. |
• | The diagnoses for three way catalyst on the current cycle has not finished. |
- While the vehicle meets the two conditions listed above, the normal running for the three-way catalyst under idle conditions should meet the following conditions;
• | The intake air temperature (IAT) is between -20 to +250° C (-4 to 482° F). |
• | Other tests are not set |
• | The battery voltage is above 11 volts. |
• | Without the evaluation of alcohol content |
• | The Engine Coolant Temperature (ECT) is within the allowable range. |
• | The Barometric Pressure (BARO) is greater than 70 kPa |
• | The idle time is less than the specified time before the intrusive test, and the idle time will increase when the speed and the throttle position (TP) angle reduce. |
• | The short term fuel trim (FT) is between -10 and 10 percent; |
• | The expected three-way catalytic temperature exceeds the specified value or the air flow of the engine is more than 12 g/s for at least 30 seconds with the throttle closed for 180 seconds. |
• | The current gear is Forward |
- After the vehicle speed is stable at idle, the normal running for three-way catalyst should meet the following conditions:
• | The mass air flow (MAF) is between 3-18 g/s; |
• | The expected catalytic temperature is less than 640° C (1184° F) |
- Three Way Catalytic Converter runs for 8 seconds while the conditions are met, check whether the following conditions related to engine fuel meet the requirements:
• | The pre-conversion times of oxygen sensor is at least once; |
• | The Short Term FT Avg is between -4 and +4 percent; |
DTCs P0420 and P0430 are Type A DTCs.
DTCs P0420 and P0430 are Type A DTCs.