In order to maintain a reasonably low emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx), the engine controls system uses a three-way catalytic converter. The catalyst within the converter promotes a chemical reaction which oxidizes the HC and CO present in the exhaust gas. This reaction converts them into harmless water vapor and carbon dioxide. The catalyst also reduces NOx, converting it to nitrogen. The powertrain control module (PCM) monitors this process using bank 1 heated oxygen sensor (HO2S) 2. Bank 1 HO2S 2, located in the exhaust stream past the three-way catalytic converter, produces an output signal which indicates the oxygen storage capacity of the catalyst. This determines the catalysts ability to convert exhaust emissions effectively. If the catalyst is functioning correctly, the bank 1 HO2S 2 signal will be far less active than that produced by bank 1 HO2S 1. This indicates that the three-way catalytic converters oxygen storage capacity is operating at a threshold considered acceptable.
When the conditions for running this DTC are met, the following occurs:
• | DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0171, P0172, P0200, P0300, P0335, P0336, P0341, P0342, P0343, P0351, P0401, P0404, P0405, P0410, P0418, P0440, P0442, P0443, P0446, P0449, P0500, P0502, P0503, P0506 , P0507, 0704, P0706, P0711, P0712, P0716, P0719, P0724, P0740, P0741, P0742, P0748, P0751, P0752, P0753, P0756, P0757, P0758, P1112, P1114, P1115, P1121, P1122, P1336, P1345, P1404, P1860, P1870, or P1875 are not set. |
• | The engine is operating longer than 400 seconds. |
• | The ECT is between 70-120°C (158-248°F). |
• | The IAT is between -15 to +167°C (5-75°F). |
• | Engine speed is more than 1,300 RPM for a minimum of 9 seconds since the end of the last idle test. |
• | The barometric pressure (BARO) is more than 74 kPa. |
• | The fuel system is operating in Closed Loop. |
The PCM determines the oxygen storage capability of the catalytic converter has degraded below a calibrated threshold.
• | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
• | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
• | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
• | Clear the MIL and the DTC with a scan tool. |
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | |||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |||||||||||
2 | Are any other DTCs set? | Go to the applicable DTC table | Go to Step 3 | ||||||||||
3 |
Did you find and correct the condition? | Go to Step 5 | Go to Step 4 | ||||||||||
Replace the catalytic converter. Refer to Catalytic Converter Replacement in Engine Exhaust. Is the action complete? | Go to Step 5 | -- | |||||||||||
5 |
Does the scan tool indicate that this test ran and passed? | Go to Step 6 | Go to Step 2 | ||||||||||
6 | Select the Capture Info option and the Review Info option using the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | Go to the applicable DTC table | System OK |