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 P2251 or P2254

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Engine Control Module Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	Start the engine. Allow the engine to reach operating temperature. Refer to Scan Tool Data List . Cycle the throttle from idle to wide open throttle (WOT) 3 times within 5 seconds while observing the HO2S Bank 1 Sensor 1 or HO2S Bank 2 Sensor 1 parameter with a scan tool. Does the affected lambda value reach the specified value as the engine decelerates?	1.989	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. Inspect the exhaust system for any leaks upstream from the affected oxygen sensor. Inspect for any exhaust leaks between the heated oxygen sensor (HO2S) 1 and the HO2S 2. Repair the exhaust leak, as necessary. Refer to Exhaust Leakage in Engine Exhaust. Did you find and correct the condition?	-	Go to Step 12	Go to Step 5
5	Disconnect the connector for the HO2S that applies to this DTC. Visually and physically inspect for the following items: The HO2S is securely installed. Terminal corrosion or water intrusion Terminal tension at the HO2S connectors Damaged wiring Repair as necessary. Refer to Heated Oxygen Sensor Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 6
6	Turn ON the ignition, with the engine OFF. Measure the voltage between the HO2S low reference circuit, on the engine harness side, and a good ground with a DMM. Is the voltage more than the specified value?	2.3 V	Go to Step 8	Go to Step 7
7	Test the HO2S low reference circuit for an open or high resistance. Refer to Circuit Testing , Wiring Repairs , and Heated Oxygen Sensor Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 9
8	Test for intermittent and poor connections at the HO2S. Refer to Testing for Intermittent Conditions and Poor Connections , Connector Repairs , and Heated Oxygen Sensor Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 10
9	Test for intermittent and poor connections at the engine control module (ECM). 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 affected HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 and Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 . Did you complete the replacement?	-	Go to Step 12	-
11	Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. 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 - Vehicle in Vehicle DTC Information	System OK