For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P0130: HO2S Signal Circuit Shorted to Heater Circuit Bank 1 Sensor 1
DTC P0150: HO2S Signal Circuit Shorted to Heater Circuit Bank 2 Sensor 1

### Circuit Description

The engine control module (ECM) supplies a voltage near 450 mV between the heated oxygen sensor (HO2S) signal circuit and the low reference circuit. The HO2S varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean. The ECM monitors and stores the HO2S voltage information. The ECM evaluates the HO2S voltage samples in order to determine the amount of time that the HO2S voltage was out of range. Or, to detect if the HO2S signal voltage switches at the same rate at which the ECM is commanding the heater ON and OFF.

### Conditions for Running the DTC

#### Condition 1 and 2

• | Before the ECM can report that DTC P0130 or P0150 failed, DTCs P0030, P0031, P0032, P0050, P0051, P0052, P0133, P0135, P0153, and P0155 must run and pass.

• | DTC P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, P0277, P2146, P2149, P2152, P2155, P216A, or P216D is not set.

• | The engine is greater than 240 RPM.

• | The ignition voltage is greater than 10 volts.

• | The HO2S 1 heater duty cycle is greater than 90 percent for greater than 5 seconds.

• | The DTCs run continuously once the conditions above exist for greater than 60 seconds.

#### Condition 3

• | Before the ECM can report that DTC P0130 or P0150 failed, DTCs P0030, P0031, P0032, P0050, P0051, P0052, P0133, P0135, P0153, and P0155 must run and pass.

• | The engine is operating.

• | The HO2S 1 heater duty cycle is greater than 70 percent or, the calculated exhaust gas temperature is warmer than 600°C (1,112°F).

• | The air flow into the engine has exceeded 10 grams.

• | The evaporative emissions system (EVAP) is not performing an intrusive test.

• | Closed loop fuel control is enabled.

• | The DTCs run continuously once the conditions above exist for greater than 30 seconds.

### Conditions for Setting the DTC

#### Condition 1

The ECM detects that the HO2S 1 signal voltage increases to greater than 2 volts within 4 ms of 4 out of 6 HO2S heater switch OFF samples.

#### Condition 2

The HO2S 1 voltage is between 520-1,150 mV and the corresponding HO2S 2 voltage is less than 100 mV.

#### Condition 3

The HO2S 1 voltage is between 60-400 mV and the corresponding HO2S 2 voltage is less than 500 mV.

### Action Taken when the DTC Sets

DTCs P0130 and P0150 are Type B DTCs.

### Conditions for Clearing the MIL/DTC

DTCs P0130 and P0150 are Type B DTCs.

### Diagnostic Aids

• | The HO2S 1 voltage should be between 350-550 mV with the ignition ON. If the voltage is greater than the specified value, there is a condition with the HO2S 1 circuits. If the voltage does not change after disconnecting the HO2S, the condition is between the sensor and the ECM. If the voltage is between 350-550 mV after disconnecting the sensor, the condition is with the HO2S 1.

• | Inspect the HO2S 1 harness connector for water intrusion. Moisture in a connector may cause voltage to bleed to other circuits within the connector.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Ignition ON, observe the appropriate scan tool HO2S 1 voltage parameter. The HO2S 1 voltage parameter should be less than 1,025 mV.
2. 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.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate HO2S 1.
2. Ignition ON, verify that the scan tool HO2S 1 parameter is between 350-500 mV.

⇒ | If greater than the specified range, test the signal circuit of the HO2S 1 for a short to the heater circuit. If the circuit/connections test normal, replace the ECM.

3. If all circuits/connections test normal, replace the appropriate HO2S.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Heated Oxygen Sensor Replacement - Bank 1 Sensor 1

• | Heated Oxygen Sensor Replacement - Bank 2 Sensor 1

• | Control Module References for engine control module replacement, setup, and programming