Spark

DTC P0130-P0134, P0137, P0138, P013A, P013B, or P0140 - FX3

The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. The control module supplies the HO2S with a reference, or bias voltage of about 450 mV. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. This voltage will fluctuate above and below the bias voltage. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases above bias voltage toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.

The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.

The HO2S utilises the following circuits:

P0131, P0132, P0137, P0138, or P0140

P0133 or P0134

P013A

P013B

P0131 or P0137

The ECM detects that the filtered HO2S signal voltage is less than 0.02V.

P0132 or P0138

The ECM detects that the filtered HO2S signal voltage is greater than 1.10V.

P0133

P0134

The ECM detects that the filtered HO2S signal voltage is between 299-600 mV.

P013A

The ECM detects that the average time for rich-to-lean transition is greater than 1 s during the deceleration fuel cut-off.

P013B

The ECM detects that the average time for lean-to-rich is greater than predetermined values during the power enrichment.

P0140

The ECM detects that the filtered HO2S signal voltage is between 0.42-0.48V.

DTC P0131, P0132, P0133, P0134, P0137, P0138, P013A, P013B, and P0140 are Type E DTCs.

DTC P0131, P0132, P0133, P0134, P0137, P0138, P013A, P013B, and P0140 are Type E DTCs.

Schematic Reference

Engine Controls Schematics : Siemens ECM - LPG with LCP → Siemens ECM - Gas without FX3 or LCP → Delphi ECM - FX3

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

1. Ignition ON, verify that the DTCs related to the HO2S heater are not set.

⇒	If a DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

Note: A front HO2S circuit condition can cause a rear HO2S DTC to set.

2. Engine running at normal operating temperature, verify that the scan tool heated oxygen sensor voltage parameters fluctuate above and below the range of 350-550 mV for HO2S 1, and within 350-550 mV for HO2S 2.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

1. Ignition OFF, disconnect the harness connector at the appropriate HO2S.

•	B52A Heated Oxygen Sensor 1 (HO2S 1)

•	B52B Heated Oxygen Sensor 2 (HO2S 2)

2. Ignition OFF for 1 minute, test for less than 5 Ω between the low reference circuit and ground.

•	Low reference circuit terminal 3 of the B52A HO2S 1 and ground

•	Low reference circuit terminal 3 of the B52B HO2S 2 and ground

⇒	If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

3. Ignition ON, test for 350-550 mV between the signal circuit and ground.

•	Signal circuit terminal 1 of the B52A HO2S 1 and ground

•	Signal circuit terminal 1 of the B52B HO2S 2 and ground

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 3. Engine running, verify the scan tool HO2S parameter is less than 60 mV.

•	Signal circuit terminal 1 and low reference circuit terminal 3 of the B52A HO2S 1

•	Signal circuit terminal 1 and low reference circuit terminal 3 of the B52B HO2S 2

⇒	If greater than the specified range, replace the K20 ECM.

5. Verify none of the following conditions exist:

•	Lean or rich fuel injectors-Refer to Fuel Injector Diagnosis with Special Tool .

•	Water intrusion in the HO2S harness connector

•	Low or high fuel system pressure--Refer to Fuel System Diagnosis .

•	Fuel that is contaminated--Refer to Alcohol/Contaminants-in-Fuel Diagnosis .

•	Fuel saturation of the evaporative emission (EVAP) canister

•	Exhaust leaks near the HO2S

•	Engine vacuum leaks

⇒	If you find any of the above conditions, repair as necessary.

6. If all circuits test normal, test or replace the appropriate HO2S.

•	B52A HO2S 1

•	B52B HO2S 2

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.