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 provide an overview of each diagnostic category.

### DTC Descriptor

DTC P0030 00: HO2S Heater Control Circuit Sensor 1
DTC P0036 00: HO2S Heater Control Circuit Sensor 2
DTC P0053 00: HO2S Heater Resistance Sensor 1
DTC P0054 00: HO2S Heater Resistance Sensor 2
DTC P0135 00: HO2S Heater Performance Sensor 1
DTC P0141 00: HO2S Heater Performance Sensor 2

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Ignition voltage | P0030 00, P0036 00, P0102 00, P0135 00, P0141 00, P0443 00, P0597 00, P059 00 | P0030 00, P0036 00, | -- | --
HO2S 1 heater control | P0030 00, P0135 00, | P0030 00, P0132 00, P0135 00, P0137 00 | P0030 00, P0135 00, P0137 00 | P0135 00
HO2S 2 heater control | P0036 00, P0141 00 | P0036 00, P0138 00, P0140 00, P0141 00 | P0036 00, P0141 00 | P0141 00

### Circuit/System Description

Heated oxygen sensors (HO2S) are used for fuel control and post-catalyst monitoring. Each heated oxygen sensors (HO2S) compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. Each heated oxygen sensor (HO2S) must reach operating temperature to provide an accurate voltage signal. A heating element inside each of the heated oxygen sensor (HO2S) minimizes the time required for the sensor to reach operating temperature. Voltage is provided to the heater by an ignition voltage circuit through a fuse. With the engine running, ground is provided to the heater by the heated oxygen sensor (HO2S) heater low control circuit, through a low side driver within the engine control module (ECM). The ECM uses pulse-width modulation (PWM) to control the heated oxygen sensor (HO2S) heater operation to maintain a specific heated oxygen sensor (HO2S) operating temperature range.

### Conditions for Running the DTC

#### P0030 00 and P0036 00

• | The ignition is ON.

• | The ignition voltage is between 11-18 V.

• | DTC P0030 00 and P0036 00 run continuously when the above conditions are met.

#### P0053 00 and P0054 00

• | DTCs P0030 00, P0036 00, P0112 00, P0113 00, P0117 00, P0118 00, or P2610 00 are not set.

• | The ignition is OFF for greater than 8 h.

• | The engine coolant temperature (ECT) and the intake air temperature (IAT) are within 8°C (14°F).

• | The ECT is between -30°C to +45°C (-22 to +113°F).

• | The ignition voltage is less than 18 V.

• | The engine run time is greater than 200 ms.

• | DTC P0053 00 and P0054 00 run once per cold start-up when the above conditions are met.

#### P0135 00 and P0141 00

• | DTCs P0117 00 or P0118 00 are not set.

• | The ignition voltage is between 10-18 V.

• | The HO2S heaters are at operating temperature.

• | The scan tool HO2S Heater device control is not active.

• | The commanded HO2S heater duty cycle is greater than 0%.

• | DTC P0135 00 and P0141 00 run twice per ignition cycle when the above conditions are met for 120 s.

### Conditions for Setting the DTC

#### P0030 00 and P0036 00

The ECM detects that the commanded state of the driver and the actual state of the control circuit do not match for greater than 5 s.

#### P0053 00 and P0054 00

The ECM detects the HO2S heater is not within a specified resistance range at engine start-up.

#### P0135 00 and P0141 00

The ECM detects the HO2S heater current is less than 0.30 amps or greater than 2.5 amps for greater than 8 s.

### Action Taken When the DTC Sets

DTC P0030 00, P0036 00, P0053 00, P0054 00, P0135 00, and P0141 00 are Type B DTCs.

### Conditions for Clearing the DTC

DTC P0030 00, P0036 00, P0053 00, P0054 00, P0135 00, and P0141 00 are Type B DTCs.

### Diagnostic Aids

• | If the condition is intermittent, move the related harnesses and connectors, with the engine operating, while monitoring the scan tool circuit status parameters for the component. The circuit status parameters change from OK or Not Run to Fault if there is a condition with the circuit or a connection.

• | An open fuse F11 in the HO2S heater circuit may be caused by the heater element in one of the sensors. The condition may not be present until the sensor operates for a period of time. If no fault is present in the heater circuit, monitor the amperage of each heater with a scan tool to determine if one of the heater elements is the cause of the open fuse. Inspect the sensor pigtail or the harness for contacting the exhaust system.

### 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. Clear the DTCs with a scan tool.
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

You must perform the circuit/system verification before proceeding with circuit/system testing.

1. Ignition OFF, disconnect the harness connector at the appropriate B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S).
2. Ignition ON, test for B+ between the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) ignition voltage circuit terminal 1 and ground.

⇒ | If less than the specified range, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition voltage circuit fuse F11 is open, test all components connected to the ignition voltage circuit and replace as necessary.

3. Ignition ON, test for 3-4 V between the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) control circuit terminal 2 and ground.

⇒ | If less than the specified range, test the control circuit for a short to ground, or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

⇒ | If greater than the specified range, test the control circuit for a short to voltage. If the circuit/connections test normal, replace the K20 Engine Control Module (ECM).

4. Engine idling, command the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) to 100% with a scan tool. The DMM should transition from 3-4 V when commanded OFF to less than 1 V when commanded to 100%.

⇒ | If the circuit voltage does not correspond to the specified values, replace the K20 Engine Control Module (ECM).

5. Ignition OFF, connect a 10 A fused jumper wire between the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S) control circuit terminal 2 and the ignition circuit terminal 1.
6. Engine idling, with the scan tool observe the appropriate HO2S Heater Amps parameter. The reading should display 0.00 amps.

⇒ | If not the specified value, test the appropriate control circuit and the appropriate ignition voltage circuit for high resistance.

7. If all circuits test normal, test or replace the appropriate B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S).

### Component Testing

#### Static Test

1. Ignition OFF, disconnect the harness connector at the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S).
2. Test for 8-20 Ω between the B52A Heated Oxygen Sensor (HO2S) ignition voltage circuit terminal 1 and the control circuit terminal 2 or the B52B Heated Oxygen Sensor (HO2S) ignition voltage circuit terminal 1 and the control circuit terminal 2.

⇒ | If not within the specified range, replace the B52A Heated Oxygen Sensor (HO2S) or B52B Heated Oxygen Sensor (HO2S).

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Heated Oxygen Sensor Replacement - Sensor 1

• | Heated Oxygen Sensor Replacement - Sensor 2

• | Control Module References for ECM replacement, setup, and programming