Circuit Description

Powertrain Control Module (PCM) continuously monitors Oxygen Sensor 1 (O2S 1) activity for 100 seconds. During monitor period, PCM counts number of times than O2S 1 switches from rich to lean and from lean to rich. If total number of switches is less than calibrated value, a DTC P1133 will set.

Conditions for setting this DTC are:

• DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0171, P0200, P0300, P0301, P0302, P0303, P0304, P0341, P0404, P0506, P0507, P0601 and P0602 not set.
• Number of lean to rich counts is less than 15, or rich to lean counts is less than 10.
• Engine speed is 1600-2600 RPM.
• TP sensor angle is 9-20 percent.
• Purge learn memory is greater than 191.
• Evaporative emission control system is commanded open for greater than 80 percent Pulse Width Modulated (PWM) on A/T.
• Evaporative emission control system is commanded open for greater than 40 percent Pulse Width Modulated (PWM) on M/T.