P1133

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The PCM continuously monitors the oxygen sensor 1 (O2S 1) activity for 100 seconds. During the monitor period, the PCM counts the number of times that the O2S 1 switches from rich to lean and from lean to rich. You can determine a total for all of the switches with this information. If the number of switches is too low, a DTC P1133 will set.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0105, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0171, P0201, P0202, P0203, P0204, P0300, P0335, P0440, P0442, P0446, P0506, P0507, P0601, P0602, or P1441 are not set.
^ The Engine Coolant Temperature (ECT) is more than 75°C (167°F).
^ The engine speed is between 1800 RPM and 2300 RPM.
^ The engine is operating in closed loop.
^ The Throttle Position (TP) angle is between 8 percent and 15 percent.
^ The evaporative emissions control system is commanded open for more than 80 percent.
^ The purge learned memory is more than approximately 0.86.
^ The diagnostic completes when 30 seconds of accumulated time has been spent in the above conditions.

CONDITIONS FOR SETTING THE DTC
The number of rich to lean counts is less than 1 or the lean to rich counts is less than 1.

ACTION TAKEN WHEN THE DTC SETS
^ The Malfunction Indicator Lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with the malfunction present.
^ The PCM will record the operating conditions at the time that the diagnostic fails. This information will store in the Freeze Frame and Failure Records buffers.
^ A history DTC stores.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The MIL will turn OFF after three consecutive ignition cycles in which the diagnostic runs without a fault.
^ A history DTC will clear after 40 consecutive warm-up cycles without a fault.
^ Use a scan tool to clear the DTCs.

DIAGNOSTIC AIDS
DTC P1133 is most likely caused by one of the following:
^ High fuel pressure - The system will go rich if fuel pressure is to high. The PCM can compensate for some increase, however, if the fuel pressure becomes too high, a DTC P0172 will be set. Refer to Fuel System Diagnosis.
^ A leaking injector - A leaking or malfunctioning injector can cause the system to go rich.
^ The MAP sensor - An output that causes the PCM to sense a higher than normal manifold pressure, indicative of a low vacuum, can cause the system to go rich. Disconnecting the MAP sensor will allow the PCM to set a fixed value for the MAP sensor. Substitute a different MAP sensor if the rich condition is gone while the sensor is disconnected.
^ The pressure regulator - Check for a leaking fuel pressure regulator diaphragm by checking for the presence of liquid fuel in the vacuum line to the regulator.
^ The TP sensor - An intermittent TP sensor output will cause the system to go rich due to a false indication of the engine accelerating.
^ O2S 1 contamination - Inspect O2S 1 for silicone contamination from fuel or use of improper RTV sealant. The sensor may have a while powdery coating, which may result in a high but false voltage signal, indicating a rich exhaust condition. The PCM will then reduce the amount of fuel that is delivered to the engine, causing a severe surge or driveability problem.

TEST DESCRIPTION
The numbers below refer to the step numbers on the Diagnostic Table.
16. The replacement PCM must be programmed and the Crankshaft Position System Variation Learn procedure.