P0160

CIRCUIT DESCRIPTION
The powertrain control module (PCM) supplies a voltage of approximately 450 mV between the heated oxygen sensor (HO2S) high and low signal circuits. The oxygen (O2) sensor varies the voltage from approximately 1,000 mV when the exhaust is rich, through approximately 10 mV when the exhaust is lean.

The PCM monitors and stores the heated oxygen sensor (HO2S) voltage information. The PCM evaluates the HO2S voltage samples in order to determine the period of time during which the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period, and determines if the majority of the samples are out of the operating range.

The PCM monitors the HO2S voltage and detects if the voltage goes out of the bias range. If the PCM does not detect that the voltage went out of the bias range, a DTC sets.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0135, P0141, P0155, P0161, P0200, P0300, P0410, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1221, P1258, P1415, P1416, P1441, P1514, P1515, P1516, P1517, or P1518 are not set.
^ The engine run time is more than 409 seconds.
^ The ignition 1 signal is between 9-18 volts.
^ The loop status is Closed.
^ Intrusive tests are not in progress.
^ Scan tool output controls are not active.

CONDITIONS FOR SETTING THE DTC
^ The HO2S signal voltage is steady between 410-490 mV for 150 seconds.
^ The throttle position (TP) indicated angle changes more than 5 percent within 1 second, 6 times.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Clear the MIL and the DTC with a scan tool.

DIAGNOSTIC AIDS

IMPORTANT:
^ Before you service the PCM and throttle actuator control (TAC) module, remove any debris from the module connector surfaces. Inspect the module connector gaskets when you diagnose or replace the modules. Ensure that the gaskets are correctly installed. The gaskets prevent contaminate intrusion into the modules.
^ For any test that requires probing the PCM or probing a component harness connector, use the J 35616-A Connector Test Adapter Kit. Using this kit prevents damage to the harness and component terminals. Refer to Using Connector Test Adapters in Diagnostic Aids.
^ 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 for contamination. Refer to Wiring Repairs in Diagnostic Aids.
^ For an intermittent condition, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-6:

Steps 7-13:

The numbers below refer to the step numbers on the diagnostic table.
2. The engine must be at the normal operating temperature before you perform this test.
3. Using the Freeze Frame and/or Failure Records data may help to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help to determine the number of miles since the DTC set. You can also use the Fail Counter and the Pass Counter in order to determine how the number of ignition cycles in which the diagnostic reported a pass and/or a fail. Operate the vehicle within the same Freeze Frame conditions that the PCM recorded, including the RPM, the load, the vehicle speed, and the temperature. This procedure isolates when the DTC failed.
4. If the scan tool indicates that the HO2S voltage goes below 200 mV, this indicates the HO2S circuits and PCM are OK.
5. This step verifies whether the low signal circuit from the PCM is OK. A voltage indicates that the PCM and the wiring are OK.
6. This step verifies whether the signal circuit from the PCM is OK.
7. Disconnecting the PCM allows you to use a DMM in order to test the circuit continuity. This procedure helps to locate an open or shorted circuit.