Conditions for Clearing the MIL/DTC

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.

DTC P0140

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Start the engine. Allow the engine to idle at operating temperature. Refer to Scan Tool Data List . Observe the HO2S 2 parameter with a scan tool. Vary the engine speed from idle to 3,000 RPM several times within 5 seconds. Does the voltage fluctuate above and below the specified range?	390-520 mV	Go to Step 3	Go to Step 4
3	Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	-	Go to Step 4	Go to Intermittent Conditions
4	Turn OFF the ignition. Disconnect the heated oxygen sensor (HO2S) 2 connector. Connect a test lamp between the HO2S 2 heater ignition voltage circuit and the HO2S 2 heater low control circuit, on the engine harness side. Turn ON the ignition, with the engine OFF. IMPORTANT: The scan tool will not display the HO2S 2 heater command status, but the HO2S 2 driver will still be commanded ON and OFF at the same time as the HO2S 1 driver. Command the HO2S 2 heater ON and OFF with a scan tool. Does the test lamp flash ON and OFF?	-	Go to Step 5	Go to Step 4 of DTC P0141
5	Turn OFF the ignition. Remove the test lamp from the previous step. Connect a 3-amp fused jumper wire between the HO2S 2 high signal circuit, on the engine harness side, and a good ground. Turn ON the ignition, with the engine OFF. Observe the HO2S 2 parameter with a scan tool. Is the voltage less than the specified value?	15 mV	Go to Step 6	Go to Step 7
6	Turn OFF the ignition. Disconnect the appropriate powertrain control module (PCM) harness connector. Measure the resistance of the HO2S 2 low signal circuit. Refer to Circuit Testing . Is the resistance within the specified range?	0-5 Ω	Go to Step 9	Go to Step 8
7	Test the HO2S 2 high signal circuit for an open or high resistance. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs . Did you find and correct the condition?	-	Go to Step 14	Go to Step 11
8	Test the HO2S 2 low signal circuit for an open or high resistance. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs . Did you find and correct the condition?	-	Go to Step 14	Go to Step 11
9	Inspect for the following that may affect the HO2S operation: NOTE: Refer to Silicon Contamination of Heated Oxygen Sensors Notice in Cautions and Notices. HO2S contamination NOTE: Refer to Heated Oxygen and Oxygen Sensor Notice in Cautions and Notices. Chafed, burnt, cut, pinched, or otherwise damaged HO2S wiring Exhaust system leaks or restrictions Evaporative emission (EVAP) system malfunction-Inspect the EVAP control system. Refer to Inspection/Maintenance (I/M) Evaporative Emission (EVAP) System Set Procedure . The fuel pressure-Incorrect fuel pressure can affect HO2S operation. Refer to Fuel System Diagnosis . Did you find and correct the condition?	-	Go to Step 14	Go to Step 10
10	Test for an intermittent and for a poor connection at the harness connector of the HO2S 2. Refer to Testing for Intermittent Conditions and Poor Connections , Connector Repairs , and Heated Oxygen Sensor (HO2S) Wiring Repairs . Did you find and correct the condition?	-	Go to Step 14	Go to Step 12
11	Test for an intermittent and for a poor connection at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 14	Go to Step 13
12	Replace the HO2S 2. Refer to Heated Oxygen Sensor Replacement - Position 2 . Did you complete the replacement?	-	Go to Step 14	-
13	Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?	-	Go to Step 14	-
14	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?	-	Go to Step 2	Go to Step 15
15	Observe the Capture Info with a scan tool. Are there any DTCs that have not diagnosed?	-	Go to Diagnostic Trouble Code (DTC) List - Vehicle	System OK