P1134 or P1154 (W/Case Grounded HO2S)

CIRCUIT DESCRIPTION
This diagnostic applies only to vehicles built with case grounded heated oxygen sensors (HO2S). To identify the HO2S, refer to Computers and Controls Systems Component Views.

The powertrain control module (PCM) monitors the HO2S activity. 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 needed to complete all transitions. With this information, an average time for all transitions can be determined. The PCM then divides the rich to lean average by the lean to rich average to obtain a ratio. A DTC sets if the HO2S ratio is not within range.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0131, P0132, P0134, P0135, P0151, P0152, P0154, P0155, P0200, P0300, P0401, P0404, P0405, P0440, P0442, P0446, P0452, P0453, P1120, P1125, P1220, P1221, P1258, P1404, P1441, P1514, P1515, P1516, P1517, or P1518 are not set.
^ The engine coolant temperature (ECT) is more than 65°C (149°F).
^ The engine run time is more than 160 seconds.
^ The evaporative emission (EVAP) purge solenoid command is more than 1 percent.
^ The mass air flow (MAF) is between 23-50 g/s.
^ The engine speed is between 1,200-3,000 RPM.
^ For vehicles without throttle-actuated control (TAC), the throttle position (TP) is more than 5 percent.
^ For vehicles with TAC, the TP indicated angle is 5 percent more than the value observed at idle.
^ The vehicle is operating in Closed Loop.
^ The ignition 1 signal is between 9-18 volts.
^ The fuel tank level remaining is more than 10 percent.
^ The fuel alcohol content is less than 90 percent.
^ Intrusive tests are not in progress.
^ The scan tool output controls are not active.
^ The above conditions are met for 100 seconds.

CONDITIONS FOR SETTING THE DTC
The HO2S transition time ratio is not within a calibrated range.

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: 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.

^ Using the Freeze Frame/Failure Records data may aid in locating an intermittent condition. If the DTC cannot be duplicated, the information included in the Freeze Frame/Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass and/or a fail. In order to isolate when the DTC failed, operate vehicle within the same Freeze Frame conditions that you observed:
^ An oxygen supply inside the HO2S is necessary for proper operation. This supply of oxygen is provided through the HO2S wires. All HO2S wires and connections should be inspected for breaks or contamination. Refer to Heated Oxygen Sensor (HO2S) Wiring Repairs in Diagnostic Aids.

For an intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-7:

Steps 8-15:

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 J 35616-A Connector Test Adapter kit. Using this kit prevents damage to the harness connector terminals.
3. When DTCs P1134 and P1154 are set at the same time, this is a good indication that a fuel contamination condition is present.
4. An exhaust leak 15.2-30.5 cm (6-12 inches) away from the HO2S can cause a DTC to set.
5. This step tests the HO2S for being tight and the connectors and circuits are OK.
6. This step tests the integrity of the HO2S low signal circuit to the PCM.
7. This step tests the integrity of the signal circuits to the PCM.