Test Description

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

The numbers below refer to the step numbers on the diagnostic table.

2: This step determines if the condition exists.
4: This step determines if the fuel system is contaminated.

DTC P0133 or P0153

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls 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	IMPORTANT: DTC P0133 is for bank 1 sensor 1 and DTC P0153 is for bank 2 sensor 1 DTC P0132 causes DTC P0153 to set. If DTC P0132 is set with DTC P0153, refer to DTC P0132 or P0152 . Inspect the heated oxygen sensor (HO2S) for being secure before proceeding with this DTC. A sensor that is loose could cause this DTC to set. Allow the engine to reach operating temperature. Operate the vehicle within the parameters specified in Conditions for Running the DTC. Observe the diagnostic trouble code (DTC) information with a scan tool. Did DTC P0133 and/or DTC P0153 fail this ignition?	-	Go to Step 4	Go to Step 3
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 Diagnostic Aids
4	Did DTC P0133 and DTC P0153 fail this ignition cycle?	-	Go to Step 7	Go to Step 5
5	Inspect for an exhaust leak near the HO2S. Refer to Exhaust Leakage in Engine Exhaust. After you inspect the exhaust system, return to this diagnostic. Did you find and correct the condition?	-	Go to Step 8	Go to Step 6
6	Inspect or test for the following conditions: Inspect that the HO2S is securely installed. Inspect for corrosion on the HO2S terminals. Inspect the terminal tension at the HO2S and at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Inspect the HO2S wiring for damage. Did you find and correct the condition?	-	Go to Step 8	Go to Step 7
7	IMPORTANT: If both DTCs are set, determine and correct the cause of the contamination before replacing a sensor. Inspect for the following conditions: Inspect for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis (w/o Special Tool) or Alcohol/Contaminants-in-Fuel Diagnosis (w/Special Tool) . Inspect for the correct RTV sealant. Inspect for engine oil consumption. Refer to Oil Consumption Diagnosis Oil Consumption Diagnosis in Engine Mechanical - 3.6L (LY7). Inspect for engine coolant consumption. Refer to Loss of Coolant (M 35) or Loss of Coolant (M 82) in Engine Cooling. Replace the HO2S. Refer to the appropriate procedure: Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 1 Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 1 Did you complete the replacement?	-	Go to Step 8	-
8	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 9
9	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