EGR/EVAP Data
EGR/EVAP DataScan Tool Data - Specific Eng., EGR/EVAP Idle/Upper Radiator Hose Hot/Closed Throttle/Park or Neutral/"Closed Loop"/ACC. "OFF"(1 Of 2):
Scan Tool Data - Specific Eng., EGR/EVAP Idle/Upper Radiator Hose Hot/Closed Throttle/Park or Neutral/"Closed Loop"/ACC. "OFF"(2 Of 2):
Engine Speed - Range 0-16384 RPM
Engine Speed is computed by the Powertrain Control Module (PCM) from the fuel control reference input. It should remain close to desired idle under various engine loads with the engine idling.
Desired Idle - Range 0-3187 RPM
The idle speed that is commanded by the PCM. The PCM will compensate for various engine loads to keep the engine at the desired idle speed.
ECT - Range -40°C to 215°C (-40°F to 419°F)
The Engine Coolant Temperature (ECT) sensor sends 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 internal resistance as temperature changes. When the sensor is cold (internal resistance high), the PCM monitors a high voltage which it interprets as a cold engine. As the sensor warms (internal resistance decreases), the voltage signal will decrease and the PCM will interpret the lower voltage as a warm engine.
IAT - Range -40°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 manner as the ECT sensor. Intake air temp is used by the PCM to adjust fuel delivery and spark timing according to incoming air density.
MAP - Range 11-105 kPa, 0-5.0 Volts
The Manifold Absolute Pressure (MAP) sensor measures the change in the intake manifold pressure which results from engine load and speed changes. As the intake manifold pressure increases, the air density in the intake also increases and additional fuel is required.
BARO - Range 11-105 kPa, 0-5.0 Volts
The Barometric Pressure (BARO) sensor measures the change in the intake manifold pressure which results from altitude changes. This value is updated at Turn the ignition "ON" and also at Wide Open Throttle (WOT).
TP Sensor - Range 0-5.0 Volts
The Throttle Position (TP) sensor is used by the PCM to determine the amount of throttle demanded by the operator of the vehicle. The TP sensor will read between 0.36-0.96 volt at idle to above 4 volts at Wide Open Throttle (WOT).
TP Angle - Range 0-100%
Throttle Position (TP) angle is computed by the PCM from the TP sensor voltage input. TP angle will auto zero to 0% at idle (TP voltage below .90 volt) and read 100% at Wide Open throttle (WOT)
O2S I - Range 0-1132 mV
The Oxygen Sensor (O2S 1) represents the exhaust oxygen sensor output voltage. This voltage will fluctuate constantly within a range between 100 mV (lean exhaust) to 900 mV (rich exhaust) when operating in "Closed Loop."
HO2S 2 - Range 0-1132 mV
The Rear Heated Oxygen Sensor (HO2S 2) represents the exhaust oxygen output voltage beyond the catalytic converter. This voltage will remain inactive or appear lazy within a range of 100 mV (lean exhaust) and 900 mV (rich exhaust) when the system is operating in "Closed Loop."
IAC Position - Range 0255 counts
The Idle Air Control (IAC) pintle position command from the PCM is displayed in counts. The higher the number of counts, the greater the commanded idle speed. Idle air control will respond fairly quickly to changes in engine load to maintain the desired idle RPM.
Fuel Trim Cell - Range 0-22
Fuel Trim Cell is dependent upon engine speed and MAP sensor readings. A plot of RPM vs. MAP is broken down into 22 cells. Fuel Trim Cell indicates which cell is currently active.
Short Term FT - Range 0-255 (-100% to 100%)
Short Term Fuel Trim (FT) represents a short term correction to fuel delivery by the PCM in response to the amount of time the oxygen sensor voltage spends above or below the 450 mV threshold. If the oxygen sensor has mainly been below 450 mV, indicating a lean air/fuel mixture, short term fuel trim will increase to tell the PCM to add fuel. If the oxygen sensor voltage stays mainly above the threshold, the PCM will reduce fuel delivery to compensate for the indicated rich condition.
Long Term FT - Range 0-255 (-100% to 100%)
Long Term Fuel Trim (FT) is derived from the short term fuel trim value and is used for long term correction of fuel delivery. A value of 128 counts (0%) indicates that fuel delivery requires no compensation to maintain a 14.7:1 air/fuel ratio. A value below 128 counts means that the fuel system is too rich and fuel delivery is being reduced (decreased injector pulse width). A value above 128 counts indicates that a lean condition exists and the PCM is compensating.
Decel EWMA - Range -10 to 10 kPa
The Exponentially Weighted Moving Average (EWMA) is an average kPa difference between the expected MAP kPa change the PCM expected to see when the diagnostic ran and the actual MAP kPa change that was seen. The EGR EWMA value should always be near -3. Whenever the EGR EWMA value becomes more positive (towards 0), then the EGR system is possibly restricted.
Desired EGR Position - Range 0 to 100%
The desired EGR position is the commanded EGR position calculated by the PCM. The higher the percentage the more the EGR valve is being commanded "ON."
EGR Actual - Range 0 to 100%
The PCM monitors the results of its commands through a feedback signal. The EGR valve sends a voltage signal back to the PCM which represents actual EGR pintle position. The EGR pintle position should remain close to desired EGR position.
EGR Decel Trip Sample Counter - Range 0 to 255 Counts
The total number of decel test samples this ignition cycle. Should never indicate greater than one unless an EGR DTC has been cleared or the battery has been disconnected.
Loop Status - Range Open/Closed
"Closed Loop" is displayed indicating that the PCM is controlling fuel delivery according to the Oxygen Sensor (O2S 1) voltage as close to an air/fuel ratio of 14.7:1 as possible.
Purge Lrn. Mem. - Range 0.00-1.00
Purge learn memory is a display of the PCM adding or subtracting fuel based on EVAP purge. This number is added to fuel trim calculations and fuel is added or subtracted there. A number near "1" indicates that fuel is being added to fuel trim and a number near "0" indicates that fuel is being taken away.
EVAP Solenoid - Range 0% to 100%
The EVAP Solenoid hen energizes allows fuel vapor to flow from the EVAP canister to the engine. The EVAP valve is normally closed and is pulse width modulated by the PCM to control vapor flow. The EVAP valve will read 0% when closed to 100% when fully opened.
Fuel Level Sensor Range - 0 to 100%
The Fuel Level Sensor determines the fuel level in the tank. The fuel level effects the rate of change of air pressure in the EVAP System. Several of the Enhanced EVAP System diagnostics are dependent upon correct fuel level.
Fuel Tank Vacuum Pressure - Range 0 to 5 Volts
The fuel tank pressure sensor measures the difference between the pressure or vacuum in the fuel tank and the outside air pressure. When the air pressure in the fuel tank is equal to the outside air pressure, such as when the fuel filler cap is removed, the output voltage of the sensor will be 1.3 to 1.7 volts.
Loop Status - Range Open/Closed
"Closed Loop" is displayed indicating that the PCM is controlling fuel delivery according to the Oxygen Sensor (O2S 1) voltage as close to an air/fuel ratio of 14.7 to 1 as possible.
Engine Run Time Range 0:00:00-18:12:15 hours:minutes:seconds
A measure of how long the engine has been running. When the engine stops running, the timer is reset to zero.