Oxygen Sensor Data

02S Data Definitions 02S 1 - Range 01132 mV: The Oxygen Sensor (O2S 1) represents the exhaust oxygen sensor output voltage. This voltage fluctuates constantly within a range of 100 mV (lean exhaust) to 900 mV (rich exhaust) when operating in a Closed Loop.

HO2S Sensor 2 - Range 0-1132 mV: The Rear Heated Oxygen Senor (HO2S 2) represents the exhaust oxygen output voltage after the catalytic converter. When this system is operating in a Closed Loop, this voltage remains inactive, or this voltage appears lazy within a range of 100 mV and 900 mV. A lean exhaust reads at 100 mV. A rich exhaust reads at 900 mV.

Engine Speed - Range 0-16384 RPM: The PCM computes the engine speed from the fuel control reference input. The engine speed should remain close to the desired idle under various engine loads with the engine idling.

Desired Idle Speed - Range 0-3187 RPM: The PCM commands the idle speed. The PCM compensates for various engine loads in order to keep the engine at the desired idle speed.

Engine Coolant Temperature (ECT) - Range -40°C to 215°C (-4O°F to 419°F): The Engine Coolant Temperature (ECT) sensor sends the engine temperature information to the PCM. The PCM supplies 5 volts to the engine coolant temperature sensor circuit. The sensor is a thermistor which changes the internal resistance as the temperature changes. When the sensor is cold, the internal resistance is high. The PCM monitors a high voltage which the PCM interprets as a cold engine. As the sensor warms, the internal resistance decreases, and the voltage signal decreases. The PCM interprets the lower voltage as a warm engine.

Intake Air Temperature (IAT) - Range -4O°C to 215°C (-40°F to 419°F): The PCM converts the resistance of the Intake Air Temperature (IAT) sensor to degrees in the same mode as the ECT sensor. The PCM uses the intake air temperature in order to adjust the fuel delivery and the spark timing according to the incoming air density.

Manifold Absolute Pressure (MAP) - Range 11-105 kPa, 0.0-5.0 Volts: The Manifold Absolute Pressure (MAP) sensor measures the change in the intake manifold pressure. These changes result from engine load changes and speed changes. As the intake manifold pressure increases, the air density in the intake increases. Additional fuel is then required.

Barometric Absolute Pressure (BARO) - Range 11-105 kPa: The Barometric Pressure (BARO) sensor measures the change in the intake manifold pressure. This change results from altitude changes. The value is updated when the ignition is turned ON and at Wide Open Throttle (WOT).

Throttle Position (TP) Sensor - Range 0.0-5.0 Volts: The PCM uses the Throttle Position (TP) sensor in order to determine the amount of throttle demanded by the vehicle's operator. The TP sensor reads between 0.36-0.96 volt at idle to above 4 volts at WOT.

TP Angle - Range 0-100%: The PCM computes the Throttle Position (TP) angle from the TP sensor voltage input. The TP angle will auto zero to 0% at idle. The TP voltage will read below 0.90 volt. The TP angle will read 100% at Wide Open Throttle (WOT).

Short Term FT - Range 0-255 (-100% to 100%): The Short Term Fuel Trim represents a short term correction of the fuel delivery. The correction is in response to the amount of time the oxygen sensor voltage is above or below 450 mV. An oxygen sensor voltage below 450 mV indicates a lean air to fuel mixture. If the oxygen sensor has mainly read below 450 mV, the short term fuel trim will increase in order to tell the PCM to add fuel. If the oxygen sensor voltage stays mainly above the threshold, the PCM will reduce the fuel delivery in order to compensate for the indicated rich condition.

Long Term - Rang. 0-255 (-100% to 100 %): The Long Term Fuel Trim (FT) is derived from the short term fuel trim value. The Long Term Fuel Trim (FT) is used for the long term correction of the fuel delivery. A value of the 128 counts (0%) indicates that the fuel delivery requires no compensation in order to maintain a 14.7:1 air to fuel ratio. A value below 128 counts means that the fuel system is too rich and the fuel delivery is being reduced. A value above 128 counts indicates that a lean condition exists for which the PCM is compensating.

Short Term FT Average - Range 0-255 (-100% to 100%): The Short Term Fuel Trim (FT) Average is derived from the short term fuel trim from all of the cells. The PCM takes all of the values. The PCM then creates one average value.

Long Term FT Average - Range 0-255 (-100% to 100%): The Long Term Fuel Trim (FT) Average is derived from the long term fuel trim from all of the cells. The PCM takes all of the values. The PCM then creates one average value.

Lean/Rich Transition - Range 0-255 Counts: The PCM counts the number of times the Oxygen Sensor (O2S1) goes from a low voltage to a high voltage within a 100 seconds. A low voltage reading indicates a lean exhaust. A high voltage reading indicates a rich exhaust.

Rich/Lean Transition - Range 0-255 Counts: The PCM counts the number of times the Oxygen Sensor (O2S1) goes from a high voltage to a low voltage within a 100 seconds. A low voltage reading indicates a lean exhaust. A high voltage reading indicates a rich exhaust.

Lean/Rich Avg. - Range 0-249 mS Counts: Following the completion of the data collection period, the PCM takes the Lean/Rich transition times. The PCM averages the transition time from the total transition times.

Rich/Lean Avg. - Range 0-249 mS: Following the completion of the data collection period, the PCM takes the Rich/Lean transition times. The PCM divides the value with the 100 second period.

Rich/Lean to Lean/Rich Ratio Bn 1 Sen. 1 - Range 0:1-15.93:1: The Rich/Lean Average is divided by the Lean/Rich average in order to find the Oxygen Sensor (O2S 1) ratio.

Calc. Air Flow - Range 0-512 g/s: The calculated air flow is a calculation based on the manifold absolute pressure. Several diagnostics use the Air Flow Calculation in order to determine when to run.

Engine Load - Range 0-100%: The LOAD indicates the engine load based on the manifold absolute pressure. The higher the percentage, the greater the load the engine is under.

Loop Status - Range Open/Closed: A Closed Loop displayed indicates that the PCM is controlling the fuel delivery according to the Oxygen Sensor voltage. The PCM controls the air to fuel ratio as close to 14.7:1 as possible.

Number of Current DTCs - Range 0-255: The # of Curr. DTCs indicates the total number of current Diagnostic Trouble Codes (DTCs) set. These current DTCs set does not necessarily mean that the Malfunction Indicator Lamp (MIL) is illuminated.

Engine Run Time - Range 0:00:00-18:12:15 hours:minutes:seconds: The engine run time is a measure of how long the engine has been running. When the engine stops running, the timer resets to zero.