P0056
DTC P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141, P0155, or P0161
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0030
- HO2S Heater Control Circuit Bank 1 Sensor 1
DTC P0036
- HO2S Heater Control Circuit Bank 1 Sensor 2
DTC P0050
- HO2S Heater Control Circuit Bank 2 Sensor 1
DTC P0053
- HO2S Heater Resistance Bank 1 Sensor 1
DTC P0054
- HO2S Heater Resistance Bank 1 Sensor 2
DTC P0056
- HO2S Heater Control Circuit Bank 2 Sensor 2
DTC P0059
- HO2S Heater Resistance Bank 2 Sensor 1
DTC P0060
- HO2S Heater Resistance Bank 2 Sensor 2
DTC P0135
- HO2S Heater Performance Bank 1 Sensor 1
DTC P0141
- HO2S Heater Performance Bank 1 Sensor 2
DTC P0155
- HO2S Heater Performance Bank 2 Sensor 1
DTC P0161
- HO2S Heater Performance Bank 2 Sensor 2
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensors 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 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 HO2S heater operation to maintain a specific HO2S operating temperature range.
Conditions for Running the DTC
P0030, P0036, P0050, or P0056
* The ignition 1 voltage is between 11-18 volts.
* The engine speed is greater than 400 RPM.
* The DTCs run continuously when the above conditions are met for 1 second.
P0053, P0054, P0059, or P0060
* DTCs P0112, P0113, P0117, P0118, or P2610 are not set.
* The engine run time is greater than 3 seconds.
* The ignition voltage is less than 18 volts.
* The ignition is OFF for greater than 8 hours.
* The engine coolant temperature (ECT) is between -30 to +45°C (-22 to +113°F) at engine start-up.
* The ECT and the intake air temperature (IAT) are within 8°C (14°F) at engine start-up.
* The DTCs run once per drive cycle when the above conditions are met.
P0135, P0141, P0155, or P0161
* DTCs P0116, P0117, P0118, P0125, or P0128 are not set.
* The ignition 1 voltage is between 10-18 volts.
* The HO2S is at operating temperature.
* The HO2S is commanded ON.
* The DTCs run once per drive cycle when the above conditions are met for 120 seconds.
Conditions for Setting the DTC
P0030, P0036, P0050, or P0056
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 seconds.
P0053, P0054, P0059, or P0060
The ECM detects the HO2S heater is not within a specified resistance range at engine start-up for greater than 1 second.
P0135 or P0155
The ECM detects that the HO2S 1 heater current is greater than 3.1 amps, or less than 0.3 amps for greater than 8 seconds.
P0141 or P0161
The ECM detects that the HO2S 2 heater current is greater than 2.9 amps, or less than 0.3 amps for greater than 8 seconds.
Action Taken When the DTC Sets
DTCs P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141. P0155, and P0161 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0030, P0036, P0050, P0053, P0054, P0056, P0059, P0060, P0135, P0141. P0155, and P0161 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing For Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
* Heated Oxygen Sensor Wiring Repairs (Heated Oxygen Sensor Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Engine idling, command the appropriate B52 HO2S heater to 100 % and 0 % with a scan tool while observing the B52 HO2S Heater Circuit Test Status parameter. The parameter should display OK or Not Run.
2. Engine idling at operating temperature, observe the scan tool B52 HO2S Heater parameter. The amperage should be within 0.3-1.5 A.
3. Engine idling at operating temperature, move the related wiring and connectors while observing the B52 HO2S Heater parameter with a scan tool. The parameter should not change with movement.
• If movement affects the parameter, repair the appropriate harness or connector.
4. 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 B52 HO2S.
2. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal D and ground.
• If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B52 HO2S heater circuit fuse is open, test all components connected to the fuse and replace as necessary.
3. Probe the appropriate control circuit terminal listed below with a test lamp connected to B+. Verify that the test lamp does not illuminate.
* B52 HO2S 1 terminal E
* B52 HO2S 2 terminal C
• If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the K20 ECM.
4. Engine idling, the test lamp should illuminate, or flash.
• If the test lamp does not illuminate, or flash, test the control circuit for a short to voltage, or an open/high resistance. If the circuit/connections test normal, replace the K20 ECM.
Note:
* Less than 10 ohm on the ignition voltage circuit, or control circuit may set a DTC. If there is resistance on a circuit the driver will remain ON and the scan tool will display greater than 0.00 amp.
* Performing this test may set additional DTCs.
5. Ignition OFF, connect a 10 A fused jumper wire between the control circuit terminal listed below and the ignition voltage circuit terminal D.
* B52 HO2S 1 terminal E
* B52 HO2S 2 terminal C
6. Engine idling, observe the appropriate B52 HO2S Heater parameter. The scan tool should display 0.00 A.
• If greater than the specified value, test the control circuit and the ignition voltage circuit for high resistance.
7. If all circuits test normal, test or replace the appropriate B52 HO2S.
Repair Instructions
Caution: Refer to Heated Oxygen Sensor Resistance Learn Reset Caution (Heated Oxygen Sensor Resistance Learn Reset Caution).
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 (Heated Oxygen Sensor Replacement - Bank 1 Sensor 1)
* Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 (Heated Oxygen Sensor Replacement - Bank 1 Sensor 2)
* Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (Heated Oxygen Sensor Replacement - Bank 2 Sensor 1)
* Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 (Heated Oxygen Sensor Replacement - Bank 2 Sensor 2)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming