P0135
DTC P0030-P0032, or P0135
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0030
- HO2S Heater Control Circuit Sensor 1
DTC P0031
- HO2S Heater Control Circuit Low Voltage Sensor 1
DTC P0032
- HO2S Heater Control Circuit High Voltage Sensor 1
DTC P0135
- HO2S Heater Performance Sensor 1
Diagnostic Fault Information
Circuit/System Description
Heated oxygen sensors (HO2S) are used for fuel control and post-catalyst monitoring. The HO2S 2 compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S 2 must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S 2 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 HO2S 2 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 2 heater operation to maintain a specific HO2S 2 operating temperature range.
Conditions for Running the DTC
P0030, P0031, P0032
* The ignition is ON.
* The Ignition 1 Signal parameter is more than 9 volts.
P0135
* DTCs P0030, P0031, P0032, P0068, P0101, P0102, P0103, P0130, P0131, P0132, P0134, P1101 are not set.
* The engine is running.
* The ignition 1 signal parameter is more than 9 volts.
Conditions for Setting the DTC
P0030, P0031, P0032
The ECM detects that the difference between the predicted voltage and the actual voltage exceeds a calibrated limit.
P0135
The ECM detects that the sensor heater resistance is more than 1,200 ohms.
Action Taken When the DTC Sets
DTCs P0030, P0031, P0032, P0135 are Type B DTCs.
Conditions for Clearing the DTC
DTCs P0030, P0031, P0032, P0135 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
* Heated Oxygen Sensor Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Clear the DTCs with a scan tool.
2. Operate the vehicle within the conditions for running and setting the DTC. The DTC should not set.
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 HO2S 1.
2. Ignition ON, verify that a test lamp illuminates between the HO2S 1 heater voltage supply circuit terminal 3 and ground.
• If the test lamp does not illuminate, test the HO2S 1 heater voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all components connected to the fuse and replace as necessary.
3. Ignition ON, verify that a test lamp does not illuminate between the HO2S 1 heater low control circuit terminal 1 and the HO2S 1 heater voltage supply circuit terminal 3.
• If the test lamp illuminates, test the HO2S 1 heater low control circuit for a short to ground. If the circuit tests normal, replace the ECM.
4. Engine running, leave the test lamp connected from the previous step. The lamp should flash or be ON steady.
• If the test lamp is not ON steady or flashing, test the HO2S 1 heater low control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
5. If the ECM and all circuits test normal, replace the HO2S 1.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Heated Oxygen Sensor 1 Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming