2014 Jeep Wrangler JK Factory Service Manual 28 - DTC-Based Diagnostics

P0131-O2 SENSOR 1/1 CIRCUIT LOW

Special Tools: Click to display a list of tools used in this procedure


For a complete wiring diagram, refer to the Wiring Information.



Possible Causes

(K892) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO GROUND
MASS AIRFLOW SENSOR
INTAKE SYSTEM LEAK OR RESTRICTION
EXHAUST SYSTEM LEAK OR RESTRICTION
EGR SYSTEM LEAK
INSUFFICIENT FUELING CONDITION
OXYGEN SENSOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).


1. DTC IS ACTIVE



NOTE: If there are any Mass Airflow Sensor or Fuel Injector DTCs present, diagnose those DTCs before proceeding with this test procedure.
1. Ignition on, engine not running.
2. With the scan tool, clear DTCs in the PCM.
3. Start the engine.
4. Allow the engine to reach normal operating temperature.
5. Test drive the vehicle under several different driving conditions.
6. With the scan tool, select View DTCs.


Is the status Active for this DTC?

Yes


No


2. CHECK THE (K892) O2 SENSOR 1/1 SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the Oxygen Sensor harness connector.
3. Disconnect the PCM C1 harness connector.
4. Measure the resistance between ground and the (K892) O2 Sensor 1/1 Signal circuit at the Oxygen Sensor harness connector.


Is the resistance above 10k Ohms?

Yes


No


3. CHECK THE AIR FILTER

1. Turn the ignition off.
2. Remove and inspect the Air Filter for soiling or excessive dirt and debris which may cause air flow restriction.
3. Check the Inlet Tube for signs of excessive dirt, snow, or ice restricting airflow into the Air Filter Box.


Were any problems found?

Yes


No


4. CHECK FOR INTAKE SYSTEM RESTRICTIONS

1. Turn the ignition off.
2. Inspect all air intake, crankcase vent and Turbocharger related hoses/tubes and connections.
3. Inspect the Charge Air Cooler inlet and outlet hoses/tubes and connections.
4. Inspect the EGR Air Flow Control Valve to ensure the valve is not stuck in the closed position.


Were any problems found?

Yes


No


5. CHECK FOR INTAKE SYSTEM AIR LEAKS

1. Remove the Crankcase Vent Heater.
2. Remove the Mass Air Flow Sensor from the Turbocharger Inlet Tube.
3. Seal off and/or plug the Turbocharger Inlet Tube where the MAF sensor was removed.
4. Connect the Evaporative Emissions Leak Detector (EELD) Kit, EELD And Accessory 8404C to the Crankcase Vent Heater port in the intake duct and begin injecting smoke into the intake system.
5. Observe all intake system components for evidence of smoke leakage.


Is there evidence of smoke leakage?

Yes


No


6. CHECK THE EXHAUST SYSTEM FOR LEAKS OR RESTRICTIONS

1. Visually inspect the entire exhaust system for damage, leaks or restrictions.


Were any problems found?

Yes


No


7. CHECK THE FUEL DELIVERY SYSTEM

1. Perform the CHECKING THE FUEL DELIVERY SYSTEM diagnostic procedure. (Refer to 29 - Non-DTC Diagnostics/Drivability - Diesel - Diagnosis and Testing) .


Were any problems found?

Yes


No


8. OXYGEN SENSOR

1. Reconnect the PCM C1 harness connector.
2. Replace the Oxygen Sensor in accordance with the service information.
3. Start the engine.
4. Allow the engine to reach normal operating temperature.
5. Monitor the scan tool for at least two minutes.
6. With the scan tool, select View DTCs.


Is the status Active for this DTC?

Yes


No


9. POWERTRAIN CONTROL MODULE

1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor and the Powertrain Control Module.
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.


Were any problems found?

Yes


No