Conditions for Clearing the MIL/DTC

WARNING: This page is about a different variant/trim than selected.

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 P2A01

Step	Action	Value(s)	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls 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 reach operating temperature. Refer to Scan Tool Data List . While observing the HO2S 2 parameter with a scan tool, quickly cycle the throttle from closed throttle to wide open throttle 3 times. Does the voltage fluctuate rapidly above and below the specified range?	295-703 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 Testing for Intermittent Conditions and Poor Connections
4	Turn OFF the ignition. Disconnect the heated oxygen sensor (HO2S) 2. Turn ON the ignition, with the engine OFF. Observe the HO2S 2 parameter on a scan tool. Is the voltage more than the specified value?	475 mV	Go to Step 10	Go to Step 5
5	Measure the voltage between the HO2S 2 low signal circuit, on the engine harness side, and a good ground with a DMM. Refer to Circuit Testing . Is the voltage more than the specified value?	1 V	Go to Step 11	Go to Step 6
6	Connect a 3-amp fused jumper wire between the HO2S 2 high signal circuit, on the engine harness side, and a good ground. Observe the HO2S parameter with a scan tool. Is the voltage less than the specified value?	15 mV	Go to Step 7	Go to Step 12
7	Remove the jumper wire from the previous step. Connect a 3-amp fused jumper wire between the high signal circuit and the low signal circuit of the HO2S 2 on the engine harness side. Observe the HO2S 2 parameter with a scan tool. Is the voltage less than the specified value?	15 mV	Go to Step 8	Go to Step 13
8	Turn OFF the ignition. Measure the resistance between the low signal circuit and heater low control circuit of the HO2S 2. Refer to Circuit Testing . Is the resistance less than the specified value?	200K ohm	Go to Step 14	Go to Step 9
9	Probe the HO2S 2 low signal circuit with a test lamp that is connected to B+. Refer to Probing Electrical Connectors . Does the test lamp illuminate?	-	Go to Step 15	Go to Step 16
10	Test the HO2S 2 high signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 21	Go to Step 18
11	Test the HO2S 2 low signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 21	Go to Step 18
12	Test the HO2S 2 high signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 21	Go to Step 18
13	Test the HO2S 2 low signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 21	Go to Step 18
14	Test the HO2S 2 low signal circuit for a short to the HO2S 2 heater low control circuit. Refer to Circuit Testing and Wiring Repairs . Did you complete the replacement?	-	Go to Step 21	Go to Step 18
15	Test the HO2S 2 low signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you complete the replacement?	-	Go to Step 21	Go to Step 18
16	Inspect for the following that may affect the HO2S operation: NOTE: Refer to Silicon Contamination of Heated Oxygen Sensors Notice . HO2S contamination NOTE: Refer to Heated Oxygen and Oxygen Sensor Notice . 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) System Check . The fuel pressure Incorrect fuel pressure-Refer to Fuel System Diagnosis . Did you find and correct the condition?	-	Go to Step 21	Go to Step 17
17	Test for an intermittent and for a poor connection at the HO2S 2. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?	-	Go to Step 21	Go to Step 19
18	Test for shorted terminals and poor connections at the powertrain control module (PCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs s. Did you find and correct the condition?	-	Go to Step 21	Go to Step 20
19	NOTE: Refer to Heated Oxygen Sensor Resistance Learn Reset Notice in Cautions and Notices. Replace the HO2S 2. Refer to Heated Oxygen Sensor 2 Replacement .Did you complete the replacement?	-	Go to Step 21	-
20	Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?	-	Go to Step 21	-
21	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 22
22	Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?	-	Go to Diagnostic Trouble Code (DTC) List - Vehicle	System OK