Engine 1 Data
DESIRED IDLE - Scan Tool Range 0-3187 RPMThe idle speed that is commanded by the PCM. The PCM will compensate for various engine loads based on engine coolant temperature to keep the engine at the desired speed.
ECT - Scan Tool Range -40°C to 151°C, (-40°F to 304°F)
The Engine Coolant Temperature (ECT) sensor is mounted in the coolant stream and sends engine temperature information to the PCM. The PCM applies 5 volts to the ECT 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 signal voltage and interprets it 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 - Scan Tool Range -40°C to 151°C, (-40°F to 304°F)
The PCM converts the resistance of the intake air temperature sensor to degrees. Intake Air Temperature (IAT) is used by the PCM to adjust fuel delivery and spark timing according to incoming air density.
IAC POSITION - Scan Tool Range 0-255
Displays the commanded position of the idle air control pintle in counts. A larger number of counts means that more air is being commanded through the idle air passage. Idle air control should respond fairly quickly to changes in engine load to maintain desired idle RPM.
TP ANGLE - Scan Tool Range 0% - 100%
TP Angle is computed by the PCM from the Throttle Position (TP) Sensor voltage. TP Angle should display 0% at idle and 100% at wide open throttle.
TP SENSOR - Scan Tool Range 0.00-5.00 Volts
The voltage being monitored by the PCM on the TP sensor signal circuit.
THROTTLE AT IDLE - Scan Tool Displays YES or NO
Indicates whether the TP Angle being monitored by the PCM is at 0% when the throttle is closed. Refer to DTC PO121 if TP sensor angle is not 0% with the throttle closed. P0121
BARO - Scan Tool Range 10-105 kPa/0.00-5.00 Volts
The Barometric Pressure reading is determined from the MAP sensor signal monitored during key up and Wide-Open Throttle (WOT) conditions. The Barometric Pressure is used to compensate for altitude differences.
MAP - Scan Tool Range 10-105 kPa/0.00-4.97 Volts
The Manifold Absolute Pressure (MAP) sensor measures the change in the intake manifold pressure from engine load, EGR flow, and speed changes. As intake manifold pressure increases, intake vacuum decreases resulting in a higher MAP sensor voltage and kPa reading. The MAP sensor signal is used to monitor intake manifold pressure changes during the EGR flow test, to update the BARO reading, and as an enabling factor for several of the diagnostics.
MAF INPUT FREQUENCY - Scan Tool Range 0-32000 Hz.
The Mass Air Flow (MAF) sensor input signal to the PCM is a frequency which varies from around 3000 Hz at idle to above 7000 Hz at Wide-Open Throttle. The PCM converts this frequency signal to grams per second to be displayed as Mass Air Flow.
MAF - Scan Tool Range 0.0-512 gm/s
Mass Air Flow (MAF) is the MAF Input Frequency converted to grams of air per second. This indicates the amount of air entering the engine.
INJ. PULSE WIDTH - Scan Tool Range 0-1000m sec.
Indicates the amount of time the PCM is commanding each injector "ON" during each engine cycle. A longer injector pulse width will cause more fuel to be delivered. INJ. Pulse Width should increase with increased engine load.
AIR FUEL RATIO - Scan Tool Range 0.0-25.5
Air Fuel Ratio indicates the PCM commanded value. In closed loop, Air Fuel Ratio should normally be around 14.2-14.7. A lower Air Fuel Ratio indicates a richer commanded mixture, which may be seen during Power Enrichment or Three Way Catalyst (TWC) Protection modes. A higher Air Fuel Ratio indicates a leaner commanded mixture. This can be seen during Decel Fuel Mode.
FUEL PUMP - Scan Tool Displays ON or OFF
Indicates the PCM commanded state of the fuel pump relay driver circuit.
VTD FUEL DISABLE - Scan Tool Displays ACTIVE or INACTIVE
The Theft Deterrent Fuel Enable circuit is an input from the Vehicle Theft Deterrent Control Module that signals the PCM to enable the injectors if the proper signal is received. The scan tool will normally display "INACTIVE." If the Vehicle Theft Deterrent Control Module does not sent the correct Theft Deterrent Fuel Enable signal to the PCM, the display will switch to "ACTIVE" and the fuel system may be disabled. Refer to DTCs P1626 P1626 or P1629, P1629or Vehicle Theft Deterrent System for further information.
ENGINE RUN TIME - Scan Tool Range 00:00:00-99:99:99 Hrs:Min:Sec
Indicates the time elapsed since the engine was started. If the engine is stopped, ENGINE RUN TIME will be reset to 00:00:00.
LOOP STATUS - Scan Tool Displays OPEN or CLOSED
"Closed Loop" indicates that the PCM is controlling fuel delivery according to oxygen sensor voltage. In "Open Loop," the PCM ignores the oxygen sensor voltage and bases the amount of fuel to be delivered on TP sensor, engine coolant, and MAF sensor inputs only.
FUEL TRIM LEARN - Scan Tool Displays NO or YES
When conditions are appropriate for enabling long term fuel trim corrections, FUEL TRIM LEARN will display yes. This indicates that the long term fuel trim is responding to the short term fuel trim. If the Fuel Trim Learn displays "NO" then long term fuel trim will not respond to changes in short term fuel trim.
HEATED OXYGEN SENSORS (HO2S BN1 SEN. 1 and HO2S BN2 SEN. 1)
Scan Tool Displays NOT READY or READY - Indicates the status of the exhaust oxygen sensors. The scan tool will indicate that the exhaust oxygen sensors are ready when the PCM detects a fluctuating HO2S voltage sufficient to allow closed loop operation. This will not occur unless the exhaust oxygen sensors are warmed up.
HEATED OXYGEN SENSORS (HO2S BN1 SEN. 1 and HO2S BN2 SEN. 1) Scan Tool Range 0-1132 mV
Represents the fuel control exhaust oxygen sensor output voltage. Should fluctuate constantly within a range between 10 mV (lean exhaust) and 1000 mV (rich exhaust) while operating in "Closed Loop."
RICH/LEAN BN1 and BN2 - Scan Tool Displays RICH or LEAN
Indicates whether oxygen sensor voltage is above a 600 mV threshold voltage (rich) or below a 300 mV threshold voltage (lean). Should change constantly while in closed loop, indicating that the PCM is controlling the air/fuel mixture properly.
HEATED OXYGEN SENSORS (Bank 1 HO2S 2 and Bank 1 HO2S 3) Scan Tool Range 0-1132 mV
Rep resents the catalyst monitor exhaust oxygen sensor output voltage. If the catalyst is operating efficiently, the Bank 1 HO2S 2 signal will be far more active than that produced by the Bank 1 HO2S 3 sensor. If the PCM detects a level of Bank 1 HO2S 3 activity that indicates the catalyst is no longer operating efficiently, DTC P0420 will be set.
SHORT TERM FUEL TRIM BN1- Scan Tool Range -11% to 20%
Short Term Fuel Trim BN1 represents a short-term correction to bank 1 fuel delivery by the PCM in response to the amount of time the bank 1 fuel control oxygen sensor voltage spends above or below the 450 mV threshold. If the oxygen sensor voltage has mainly remained less than 450 mV, indicating a lean air/fuel mixture, short term fuel trim will increase into the positive range above 0% and the PCM will add fuel. If the oxygen sensor voltage stays mainly above the threshold, short term fuel trim will decrease below 0% into the negative range while the PCM reduces fuel delivery to compensate for the indicated rich condition. Under certain conditions such as extended idle and high ambient temperatures, canister purge may cause Short Term Fuel Trim to read in the negative range during normal operation. The PCM's maximum authority to control fuel trim allows a range between -11% and +/-20%. Fuel trim values at maximum authority may indicate an excessively rich or lean system.
LONG TERM FUEL TRIM BN1 Scan Tool Range -23% to 16%
Long Term Fuel Trim BN1 is derived from the Short Term Fuel Trim BN1 value and represents a long-term correction of bank 1 fuel delivery. A value of 0% indicates that fuel delivery requires no compensation to maintain the PCM commanded air/fuel ratio. A negative value significantly below 0% indicates that the fuel system is rich and fuel delivery is being reduced (decreased injector pulse width). A positive value significantly greater than 0% indicates that a lean condition exists and the PCM is compensating by adding fuel (increased injector pulse width). Because Long Term Fuel Trim tends to follow Short Term Fuel Trim; a value in the negative range due to canister purge at idle should not be considered unusual. The PCM's maximum authority to control long term fuel trim allows a range between -23% and +16%. Fuel trim values at maximum authority may indicate an excessively rich or lean system.
SHORT TERM FUEL TRIM BN2- Scan Tool Range -11% to 20%
Short Term Fuel Trim BN2 represents a short-term correction to bank 2 fuel delivery by the PCM in response to the amount of time the bank 2 fuel control oxygen sensor voltage spends above or below the 450 mV threshold. If the oxygen sensor voltage has mainly remained less than 450 mV, indicating a lean air fuel mixture, short term fuel trim will increase into the positive range above 0% and the PCM will add fuel. If the oxygen sensor voltage stays mainly above the threshold, short term fuel trim will decrease below 0% into the negative range while the PCM reduces fuel delivery to compensate for the indicated rich condition. Under certain conditions such as extended idle and high ambient temperatures, canister purge may cause Short Term Fuel Trim to read in the negative range during normal operation. The PCM's maximum authority to control short term fuel trim allows a range between -11% and +20%. Fuel trim values at maximum authority may indicate an excessively rich or lean system.
LONG TERM FUEL TRIM BN2 - Scan Tool Range -23% to 16%
Long Term Fuel Trim BN2 is derived from the Short Term Fuel Trim BN2 value and represents a long-term correction of bank 2 fuel delivery. A value of 0% indicates that fuel delivery requires no compensation to maintain the PCM commanded air/fuel ratio. A negative value significantly below 0% indicates that the fuel system is rich and fuel delivery is being reduced (decreased injector pulse width). A positive value significantly greater than 0% indicates that a lean condition exists and the PCM is compensating by adding fuel (increased injector pulse width). Because Long Term Fuel Trim tends to follow Short Term Fuel Trim; a value in the negative range due to canister purge at idle should not be considered unusual. The PCM's maximum authority to control fuel trim allows a range between -23% and +16%. Fuel trim values at maximum authority may indicate an excessively rich or lean system.
FUEL TRIM CELL - Scan Tool Range 0-9
Fuel trim cell is dependent upon engine speed and MAF sensor readings. A plot of RPM vs. MAF is divided into 10 cells. Fuel trim cell indicates which cell is currently active.
ENGINE LOAD - Scan Tool Range 0%-100%
Engine load is calculated by the PCM from engine speed and MAF sensor readings. Engine Load should increase with an increase in RPM or airflow.
DESIRED EGR POS. - Scan Tool Range 0%-100%
Represents the EGR pintle position that the PCM is commanding. Desired EGR Pos. should stay close to Actual EGR Pos.
ACTUAL EGR POS. - Scan Tool Range 0%-100%
Represents the actual position of the EGR pintle in percent. 0% displayed indicates a fully extended pintle (EGR valve closed).
VEHICLE SPEED - Scan Tool Range 0-255 km/h, (0-155 mph)
The vehicle speed sensor signal is converted into km/h and mph for display.
CURRENT GEAR - Scan Tool Displays 1, 2, 3, or 4
The PCM looks at Trans Range position and the gear commanded by the PCM. The actual forward gear that the transmission is in will be the lower of the two because the manual valve can override the PCM commanded gear.
TRANS RANGE - Scan Tool Displays INVALID, PARK/NEUTRAL, REVERSE, DRIVE 4, DRIVE 3, DRIVE 2, or LOW
Trans Range represents the decoded status of the three transmission range pressure switch inputs from the Transmission Range Pressure Switch Assembly. The combination of transmission range inputs indicates the position of the transmission manual valve.
TRANS RANGE ABC- Scan Tool Displays X or 0
The Trans Range ABC display represents the states of the three inputs from the Transmission Range Pressure Switch Assembly. "X" indicates a B+ voltage signal being monitored at the PCM, "0" indicates a grounded input signal. The combination of transmission range inputs indicates the position of the transmission manual valve.
COMMANDED TCC - Scan Tool Displays ENGAGED or DISENGAGED
Represents the PCM commanded state of the transmission torque converter clutch.
IGNITION 1 - Scan Tool Range 0-25.5 Volts
This represents the system voltage measured by the PCM at its ignition feed (CKT 439).
COMMANDED GEN - Scan Tool Displays ON or OFF
OFF displayed indicates that the PCM has commanded the generator L terminal "OFF"
GENERATOR LAMP - Scan Tool Displays ON or OFF
"ON" displayed indicates the PCM commanded state of the generator lamp/check gauges lamp due to low system voltage or a generator fault detected.
MIL - Scan Tool Displays ON or OFF
Indicates the PCM commanded state of the Malfunction Indicator Lamp.
CRUISE ENGAGED - Scan Tool Displays YES or NO
Represents the state of the Cruise Status Input form the SMCC module. CRUISE ENGAGED should not display YES unless the vehicle is operating in a cruise control mode.
CRUISE INHIBITED - Scan Tool Displays YES or NO
YES displayed indicates that the PCM is commanding the SMCC module to inhibit cruise control operation. Should display YES at idle.
TWC PROTECTION - Scan Tool Displays ACTIVE or INACTIVE
ACTIVE displayed indicates that the PCM has detected conditions appropriate to operate in TWC Protection mode. This is determined based on Engine Load and Engine Coolant Temperature. While in TWC Protection, the PCM will decrease Air/Fuel Ratio to a value that depends on Mass Air Flow (higher Mass Airflow = lower Air/Fuel Ratio).
HOT OPEN LOOP - Scan Tool Displays ACTIVE or INACTIVE
ACTIVE displayed indicates that the PCM has detected conditions appropriate to operate in Hot Open Loop mode. The PCM determines this based on Engine Coolant Temperature, Mass Air Flow and Vehicle Speed. While in Hot Open Loop, the PCM ignores inputs from the exhaust oxygen sensors and bases fuel delivery on Throttle Position, Engine Coolant Temperature, and Mass Air Flow.
DECEL FUEL MODE - Scan Tool Displays ACTIVE or INACTIVE
ACTIVE displayed indicates that the PCM has detected conditions appropriate to operate in Deceleration Fuel mode. The PCM will command deceleration fuel mode when a sudden decrease in throttle position has been detected while the vehicle is traveling over 20 mph. While in Deceleration Fuel mode, the PCM will decrease the amount of fuel delivered by entering Open Loop and decreasing the injector pulse width.
POWER ENRICHMENT - Scan Tool Displays ACTIVE or INACTIVE
ACTIVE displayed indicates that the PCM has detected conditions appropriate to operate in Power Enrichment mode. The PCM will command Power Enrichment mode when a large increase in throttle position and load is detected. While in Power Enrichment, the PCM will increase the amount of fuel delivered by entering Open Loop and increasing the injector pulse width. This is done to prevent a possible sag or hesitation from occurring during acceleration.