P0153
Diagnostic Chart:
Diagnostic Chart:
Wiring Diagram:
CIRCUIT DESCRIPTION
IMPORTANT: If a 10 megohm digital voltmeter measures this voltage, the voltage may read as low as 0.32 volt. The Heated Oxygen Sensor (HO2S) varies the voltage within a range of about 1.0 volt (1000mV) if the exhaust is rich to as low as 0.1 volt (100 mV) if the exhaust is lean.
The Vehicle Control Module (VCM) supplies a voltage of approximately 0.45 volt (450 mV) between the HO2S High and the HO2S Low circuits.
The VCM monitors the Heated Oxygen Sensor (HO2S) activity for 100 seconds after the Closed Loop. During the monitor period, the VCM counts the number of times that the HO2S switches from rich to lean and from lean to rich, and adds the amount of time the sensor took to complete all switches With this information, the VCM determines an average time. If the average time to switch is too slow, a DTC P0153 sets.
When the HO2S temperature is below 360°C (600°F), the sensor will not produce any voltage. The sensor will behave like an open circuit. This will result in an Open Loop operation.
The HO2S heater provides for a faster sensor warm-up which allows the sensor to become active in a shorter period of time and remain active during a long extended idle. The DTC P0153 determines if the HO2S is functioning properly by checking its response time.
CONDITIONS FOR SETTING THE DTC
The following conditions will set the DTC:
^ No Throttle Position (TP) sensor DTCs.
^ No EVAP DTCs.
^ No Intake Air Temperature (IAT) sensor DTCs.
^ No Manifold Absolute Pressure (MAP) sensor DTCs.
^ No Engine Coolant Temperature (ECT) sensor DTCs.
^ No Mass Air Flow (MAF) sensor DTCs.
^ No intrusive test in progress.
^ No device controls active.
^ System voltage measures at least 9.0 volts.
^ The HO2S average transition time from lean to rich and rich to lean is greater than 125 ms.
Response Test Enable
^ A Closed Loop Low Map not active.
^ DTCs P0151, P0152, P0154, and P0155 are not active.
^ A Closed Loop.
^ The ECT is greater than 57°C (134.3°F).
^ The engine run time is greater than 75 seconds.
^ Engine speed is between 1100-3000 RPM.
^ The MAF is between 15-55 g/s.
^ The EVAP canister purge duty cycle is greater than 0%.
^ The above conditions are present for more than 2 seconds.
ACTION TAKEN WHEN DTC SETS
The VCM turns the Malfunction Indicator Lamp (MIL) ON after the second test failure.
CONDITIONS FOR CLEARING THE MIL/DTC
^ The VCM turns the MIL OFF after 3 consecutive drive trips when the test has Run and Passed and not Failed.
^ A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle).
^ Use the scan tool Clear Information function.
^ Disconnect the VCM battery feed for 30 seconds.
DIAGNOSTIC AIDS
IMPORTANT: Never solder or attempt to repair HO2S wires.
Check for the following conditions:
^ An improperly installed air intake duct.
^ The air intake duct for collapsed ducting, restrictions, or a missing or plugged air filter.
^ Throttle body and intake manifold vacuum leaks.
^ A damaged or blocked throttle body inlet.
^ Exhaust system for corrosion, leaks, or loose or missing hardware.
^ The HO2S is installed securely and the pigtail harness is not contacting the exhaust manifold or wires.
^ HO2S contamination.
^ The vacuum hoses for splits, kinks, and proper connections.
^ Excessive water, alcohol, or other contaminants in the fuel.
^ VCM sensor grounds that are clean, tight, and properly positioned.
TEST DESCRIPTION
The numbers below refer to the step numbers in the diagnostic table.
4. This step checks for physical damage to the engine components and the converter.