P0153

Circuit Description
The PCM continuously monitors the Heated Oxygen Sensor (HO2S) activity for 100 seconds. During the monitor period the PCM counts the number of times that the HO2S responds from rich to lean and from lean to rich and adds the amount of time it took to complete all transitions. With this information, the PCM can determine the average time for all transitions. If the average response time is too slow, a DTC will set.

The PCM determines the lean to rich transition when the HO2S voltage changes from less than 300 mV to greater than 600 mV. The PCM determines the rich to lean transition when the HO2S voltage changes from more than 600 mV to less than 300 mV. A HO2S that responds too slowly is most likely defective. Replace the HO2S.

Conditions for Running the DTC
^ DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0200, P0335, P0336, P0351-P0358, P1258 not set.
^ The engine coolant temperature is greater than 65°C (149°F).
^ The ignition voltage is greater than 9.0 volts.
^ The AIR, EGR, and the Catalyst diagnostics are not active.
^ The fuel system is operating in Closed Loop.
^ The engine speed is between 1,200 RPM and 3,000 RPM.
^ The engine air flow is between 23 g/s and 50 g/s.
^ The EVAP canister purge duty cycle is greater than 0%.
^ The engine run time is greater than 120 seconds.

Conditions for Setting the DTC
^ The lean to rich response (below 300 mV to above 600 mV) average time is greater than 250 milliseconds.
^ The rich to lean response (above 600 mV to below 300 mV) average time is greater than 250 milliseconds.
^ The above conditions are met for 100 seconds.

Action Taken When the DTC Sets
^ The PCM illuminates the Malfunction Indicator Lamp on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure records.

Conditions for Clearing the MIL/DTC
^ The PCM turns the MIL OFF after three consecutive ignition cycles that the diagnostic runs and does not fail.
^ A last test failed (current DTC) clears when the diagnostic runs and does not fail.
^ A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
^ Use a scan tool in order to clear the MIL/DTC.

Diagnostic Aids

Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

^ A malfunction in the HO2S heater circuits will cause a DTC to set. Check the HO2S heater circuits for intermittent opens/connections. Refer to Intermittents and Poor Connections Diagnosis. Intermittent Conditions
^ An oxygen supply inside the HO2S is necessary for proper operation. The HO2S wires provides the supply of oxygen. Inspect the HO2S wires and connections for breaks or contamination.
^ Using the Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed. For an intermittent condition, refer to Symptoms. Symptom Related Diagnostic Procedures

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the fault is present. This test may take 5 minutes for the diagnostic to run. For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616-A. Using this kit prevents damage to the harness connector terminals.
3. When DTCs P0133 and P0153 are set at the same time, it is a good indication that a fuel contamination problem is present.
4. An exhaust leak 6-12 inches away from the HO2S can cause a DTC to set.
5. This step tests whether a good ground circuit is available.
6. This step tests the integrity of the signal circuit to the PCM.
7. This step tests the integrity of the signal circuit to the PCM.
8. Certain RTV silicone gasket materials give off vapors that can contaminate the HO2S. There is also a possibility of silicone contamination caused by silicone in the fuel. If the sensors appear to be contaminated by silicone and all the silicone sealant is a non silicone base, advise the customer to try a different fuel company. A missing fuel filler restrictor indicates the customer may have used leaded fuel.