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 P0138

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-Engine Controls?	-	Go to Step 2	Go to Diagnostic System Check - Engine Controls
2	Is DTC P0140 also set?	-	Go to DTC P0140	Go to Step 3
3	Start the engine. Allow the engine to idle at operating temperature. Refer to Scan Tool Data List . Clear the DTC and record the Freeze/Frame Failure Records. Observe the heated oxygen sensor (HO2S) 2 voltage parameter with a scan tool. Vary the engine speed from idle to 3,000 RPM several times within 5 seconds. Is the HO2S 2 voltage more than the specified value?	920 mV	Go to Step 5	Go to Step 4
4	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 5	Go to Intermittent Conditions
5	Turn OFF the ignition. Disconnect the HO2S 2 connector. Connect a 3-amp fused jumper wire between the HO2S 2 low signal circuit, on the engine harness side, and a good ground. Turn ON the ignition, with the engine OFF. Observe the HO2S 2 voltage parameter with a scan tool. Is the HO2S 2 voltage more than the specified value?	920 mV	Go to Step 6	Go to Step 7
6	Test the HO2S 2 high signal circuit for a short to voltage. Refer toCircuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 9
7	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 for contamination NOTE: Refer to Heated Oxygen and Oxygen Sensor Notice in Cautions and Notices. Chafed, burnt, cut, pinched, or otherwise damaged HO2S wiring The HO2S must have a clean air reference in order to function properly. This clean air reference is obtained by way of the HO2S wires. Obstruction of the air reference and degraded HO2S performance could result from any attempt to repair the above conditions. Exhaust system leaks or restrictions Evaporative Emissions (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 12	Go to Step 8
8	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 and Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 10
9	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 in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 11
10	Replace the HO2S 2. Refer to Heated Oxygen Sensor Replacement - Position 2 . Did you complete the replacement?	-	Go to Step 12	-
11	Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement . Did you complete the replacement?	-	Go to Step 12	-
12	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 13
13	Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?	-	Go to Diagnostic Trouble Code (DTC) List	System OK