Diagnostic Aids

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

Use the J 35616 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector.
The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to Engine Controls Component Views .
The rear HO2S will not go into closed loop when the engine is idling. Once the HO2S are at operating temperature, and the vehicle is moving, the rear HO2S will go into closed loop.
For an intermittent condition, refer to Intermittent Conditions .

DTC P0137 or P0157

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 P0137 is for bank 1 sensor 2 and DTC P0157 is for bank 2 sensor 2. 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 engine above 1,200 RPM for 30 seconds. Observe the appropriate HO2S voltage parameter with a scan tool. Is the voltage less than the specified value?	60 mV	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	Turn OFF the ignition. Disconnect the appropriate HO2S. Turn ON the ignition, with the engine OFF. Observe the HO2S voltage parameter with a scan tool. Is the HO2S voltage within the specified range?	350-550 mV	Go to Step 6	Go to Step 5
5	Turn OFF the ignition. Disconnect the engine control module (ECM) connector. Test the appropriate HO2S signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	-	Go to Step 9	Go to Step 8
6	Test or inspect for the following conditions: An injector that is too lean-Refer to Fuel Injector Balance Test with Special Tool . A fuel system that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (w/o Special Tool) or Alcohol/Contaminants-in-Fuel Diagnosis (w/Special Tool) . A fuel pressure that is too low-Refer to Fuel System Diagnosis . An exhaust leak near the HO2S-Refer to Symptoms - Engine Exhaust in Engine Exhaust. A vacuum or crankcase leak Did you find and correct the condition?	-	Go to Step 9	Go to Step 7
7	Replace the HO2S. Refer to the appropriate procedure: Heated Oxygen Sensor (HO2S) Replacement Bank 1 Sensor 2 Heated Oxygen Sensor (HO2S) Replacement Bank 2 Sensor 2 Did you complete the replacement?	-	Go to Step 9	-
8	Replace the ECM. Refer to Engine Control Module (ECM) Replacement . Did you complete the replacement?	-	Go to Step 9	-
9	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 10
10	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