Part 2

Scan Tool Data Definitions

Fuel Tank Rated Capacity
- This parameter displays the rated maximum quantity of fuel the fuel tank will hold. This is calibrated in the control module to match the vehicle.

Fuel Trim Cell
- This parameter displays the fuel trim cell number as calculated by the control module based on engine speed and load inputs. The scan tool will display a lower number as conditions are nearer to idle, and a higher value as conditions approach maximum engine speed and maximum load.

Fuel Trim Learn
- This parameter indicates if the control module is adjusting long term fuel trim in response to the short term fuel trim. The scan tool displays Enabled or Disabled. When conditions are appropriate for enabling long term fuel trim corrections, the scan tool displays Enabled.

Fuel Volatility
- This parameter indicates the rate the fuel can be vaporized in the cylinder as calculated by the control module. The scan tool will display HIGH when the fuel volatility is high. The scan tool will display LOW when the fuel volatility is low.

HO2S 1
- The scan tool displays a range of 0-1,106 mV.

HO2S 1 Heater
- This parameter displays the current through the control module when the heated oxygen sensor (HO2S) 1 heater is commanded ON by the control module. HO2S 1 Heater Current is a range of values indicating a low current when the heater circuit resistance is high to a high current when the heater circuit resistance is low.

HO2S 1 Heater Circuit Status
- This parameter displays the diagnostic state of the output driver for the heater control circuit of oxygen sensor 1. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an open, short to ground, or a short to voltage on the circuit.

HO2S 1 Heater Command
- This parameter displays the commanded state of the heater control circuit for oxygen sensor 1. The oxygen sensor 1 heater should be on when the scan tool indicates the HO2S 1 Heater Command is On. The oxygen sensor 1 heater should be off when the scan tool indicates the HO2S 1 Heater Command is Off. The scan tool displays 1=On /0=Off.

HO2S 2
- The scan tool displays a range of 0-1,106 mV.

HO2S 2 Heater
- This parameter displays the current through the control module when the HO2S 2 heater is commanded ON by the control module. HO2S 2 Heater Current is a range of values indicating a low current when the heater circuit resistance is high to a high current when the heater circuit resistance is low.

Hot Open Loop
- This parameter indicates the status of the fuel delivery system. The scan tool will display Active if the fuel system is running in open loop due to a temperature concern. The scan tool will display Inactive if the fuel system is operating normally.

IAT Sensor
- The scan tool displays °C. The powertrain control module (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.
The scan tool displays a range of -39 to +140°C (-38 to +284°F). The PCM converts the resistance of the intake air temperature sensor to degrees. The PCM uses the IAT in order to adjust fuel delivery and spark timing according to incoming air density.

Ignition 1 Signal
- This parameter displays the voltage measured at the ignition 1 circuit of the control module. Voltage is applied to the control module when the ignition switch is in the ignition 1 position.

Ignition Off Time
- The scan tool displays time in minutes.
This parameter is used by the control module to identify the amount of time that has passed. This parameter is used for various components and systems including throttle actuator control (TAC) system and the EVAP system.

Injector PWM
- The scan tool displays mS.
Indicates the base pulse width modulation (PWM) or ON time of the fuel injectors in milliseconds. When the engine load is increased, the injector pulse width will increase.
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. Injector pulse width should increase with increased engine load.

Knock Retard
- The scan tool displays °.
Indicates the amount of spark the PCM is removing from ignition control (IC) spark advance in response to the signal from the knock sensors. The traction control system desired torque signal from the electronic brake and traction control module (EBTCM) may cause knock retard to display a value more than 0.0 degrees if traction control is active.

Long Term FT
- The scan tool displays percentage. The PCM derives the long term fuel trim from the short term fuel trim value. The long term fuel trim represents a long term correction of fuel delivery. A value of 0 percent indicates that fuel delivery requires no compensation in order to maintain the PCM commanded air/fuel ratio. A negative value significantly below 0 percent indicates that the fuel system is rich and the PCM is reducing the fuel delivery. A positive value significantly more than 0 percent indicates that a lean condition exists and the PCM compensates by adding fuel. Fuel trim values at maximum authority indicates an excessively rich or lean system.

Long Term FT Avg.
- This parameter is the average long term fuel trim for this bank as calculated by the control module. The scan tool will display a value more than 0 percent indicating that time is being added to the injector pulse width, increasing the amount of fuel to this bank of the engine. The scan tool will display a value of less than 0, indicating time is being subtracted from the injector pulse width, reducing the amount of fuel to this bank of the engine. A value of 0 percent indicates no compensation is required to operate the engine at the desired air/fuel ratio.

Loop Status
- 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 throttle position (TP) sensor, ECT, and mass air flow (MAF) sensor inputs only.

MAF Sensor
- The scan tool displays g/s
The scan tool displays a range of 0.0-655 g/s. The MAF is the MAF input frequency converted to grams of air per second. This indicates the amount of air entering the engine.

MAF Sensor
- The scan tool displays a range of 0-31,999 Hz. The MAF sensor is a hot wire type air flow sensor. The PCM converts current draw needed by the MAF to keep the hot wires at a constant into a frequency signal. The scan tool displays this frequency in a hertz signal.

MAP Sensor
- The scan tool displays kPa
The 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.
The scan tool displays a range of 10-105 kPa. The MAP sensor measures the absolute pressure in the intake manifold.

MAP Sensor
- The scan tool displays Volts
The 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.
The scan tool displays a range of 10-105 kPa. The MAP sensor measures the absolute pressure in the intake manifold.

MIL Circuit Status
- This parameter displays the status of the output driver for the malfunction indicator lamp (MIL) control circuit. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an open, short to ground or a short to voltage on the circuit.

MIL Command
- This parameter displays the commanded state of the MIL control circuit. The malfunction indicator lamp should be ON when the scan tool indicates the MIL Command is ON. The malfunction indicator lamp should be OFF when the scan tool indicates the MIL Command is OFF. The control module will command the MIL On when the ignition is ON with the engine OFF in order to perform a bulb check.

MIL Requested by DTC
- This parameter indicates the reason the control module illuminated the MIL. The scan tool will display YES when the MIL is requested as a result of an A or B type DTC. The scan tool will display NO if the MIL is illuminated for another reason, such as transmission DTCs.

Misfire Current Cyl. 1-4
- The scan tool displays 0-255 counts. The display shows the number of misfires that have been detected during the last 200 cylinder firing events. The counters may normally display some activity, but the activity should be nearly equal for all of the cylinders, and in low numbers.

Misfire History Cyl. 1-4
- The scan tool range is 0-255 counts. This parameter indicates the total level of misfire that has been detected on each cylinder. The misfire history counters will not update or show any activity until a misfire or DTC P0300 has become active. The misfire history counter will update every 200 cylinder firing events.

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.

Reduced Engine Power
- The scan tool displays Active or Inactive. The scan tool displays Active when the PCM receives a signal from the TAC module that a throttle actuator control system fault is occurring. The PCM limits the engine power.

Short Term FT
- The scan tool displays percentage. The short term fuel trim represents a short term correction to fuel delivery by the PCM in response to the amount of time the fuel control oxygen sensor voltage spends above or below the 450 mV threshold. If the oxygen sensor voltage mainly remains less than 450 mV, indicating a lean air/fuel mixture, short term fuel trim increases into the positive range above 0 percent. The PCM adds fuel. If the oxygen sensor voltage stays mainly above the threshold, the short term fuel trim decreases below 0 percent into the negative range. The PCM reduces the fuel delivery in order to compensate for the indicated rich condition. Under certain conditions such as an extended idle and a high ambient temperature, the canister purge may cause the short term fuel trim to read in the negative range during normal operation. The fuel trim values at maximum authority may indicate an excessively rich or lean system.

Short Term FT Avg.
- The scan tool displays %. This parameter indicates the average short term fuel trim for this bank. The scan tool will display a value more than 0 if the time is being added to the injector pulse width, increasing the amount of fuel to that bank of the engine to compensate for a lean condition sensed by the oxygen sensors on that bank. The scan tool will display a value less than 0 if time is being subtracted from the injector pulse width, reducing the amount of fuel to the engine to compensate for a rich condition sensed by the oxygen sensors on that bank. A value of 0 percent indicates no compensation is required to operate the engine at the desired air/fuel ratio.

Spark
- The scan tool displays a range of -64 to +64°. The scan tool displays the amount of degrees the PCM commands. The PCM computes the desired spark advance using the following: (1) ECT, (2) engine speed (RPM), (3) load, (4) vehicle speed. The PCM adjusts the timing.
A negative (-) value indicates degrees before top dead center (BTDC) or spark advance; a positive value indicates degrees after top dead center (ATDC) or spark retard.

Start Up ECT
- Indicates the engine coolant temperature at engine start up.
The scan tool displays a range of -39 to +140°C (-38 to +284°F). The scan tool displays the engine ECT at the time the engine was started. The PCM uses start-up ECT for certain DTCs.
Indicates the engine coolant temperature at the time that the vehicle was started. Used to determine if the last startup was a cold start.

Start Up IAT
- Indicates the IAT at the time that the vehicle was started. Used to determine if the last startup was a cold start.
The scan tool range is -39 to +140°C (-38 to +284°F). This parameter indicates the ambient air temperature at start-up.

Torque Delivered Signal
- Represents the pulse width modulation (PWM) signal which indicates the percent of available torque the engine is delivering to the drive wheels. The EBTCM monitors the traction control torque signal to ensure that the PCM is responding properly to the traction control desired torque signal.

Torque Request Signal
- Represents the PWM signal from the EBTCM. The EBTCM reduces the traction control desired torque signal pulse width when a drive wheel slippage situation is detected. The PCM monitors the traction control desired torque signal and reduces drive wheel slippage as necessary by retarding spark timing, decreasing boost sol. PWM, or increasing air/fuel ratio. The PCM can also turn OFF up to three fuel injectors if the traction control desired torque signal indicates a large enough amount of drive wheel slippage.

Total Misfire Count
- The scan tool range is 0-255 counts. This parameter indicates the total level of misfire that has been detected on each cylinder. The misfire history counters will not update or show any activity until a misfire or DTC P0300 has become active. The misfire history counter will update every 200 cylinder firing events.

TP 1 Learned Min
- This parameter displays the learned minimum value of TP sensor 1 as recorded by the control module on start-up for the ignition cycle.

TP 2 Learned Min
- This parameter displays the learned minimum value of TP sensor 2 as recorded by the control module on start-up for the ignition cycle.

TP Desired Angle
- The scan tool displays %. The scan tool displays 0-100 percent. The PCM indicates the desired throttle angle commanded by the vehicle operator. The scan tool indicates the desired throttle angle commanded by the vehicle operator.

TP Indicated Angle
- This parameter displays the angle of the TP in percent. This information is calculated by the control module using the signals from the throttle position sensors. The scan tool will display a low percentage when the throttle plate is closed. The scan tool will display a high percentage when the throttle plate is fully open.

TP Sensor 1
- This parameter displays the voltage signal sent to the control module from the sensor used to monitor the position of the throttle plates. This parameter is for sensor 1 of the TP sensor assembly. The scan tool will display a low voltage when the throttle plates are at rest. The scan tool will display a high voltage when the throttle plates are fully open.

TP Sensor 1
- This parameter displays the angle of the TP sensor 1 in percent. This information is calculated by the control module using the signal from the throttle position sensor 1. The scan tool will display a low percentage when the throttle plates are closed. The scan tool will display a high percentage when the throttle plates are fully open.

TP Sensors 1 and 2
- This parameter displays the results of a control module test that compares the signals from the TP sensors 1 and 2. The scan tool will display Agree when the signal from TP sensor 1 corresponds with the signal from TP sensor 2. The scan tool will display Disagree when the signal from TP sensor 1 conflicts with the signal from TP sensor 2.

TP Sensor 2
- This parameter displays the voltage signal sent to the control module from the sensor used to monitor the position of the throttle plates. This parameter is for sensor 2 of the TP sensor assembly. The scan tool will display a high voltage when the throttle plates are at rest. The scan tool will display a low voltage when the throttle plates are fully open.

TP Sensor 2
- This parameter displays the angle of the TP sensor 2 in percent. This information is calculated by the control module using the signal from the throttle position sensor 2. The scan tool will display a low percentage when the throttle plates are closed. The scan tool will display a high percentage when the throttle plates are fully open.

Traction Control Status
- This parameter displays the status of the traction control circuit. The scan tool displays active if the PCM receives a signal from the EBTCM requesting torque reduction during a traction control event.

Vehicle Speed Sensor
- This parameter indicates the vehicle speed as calculated by the control module based on a signal from the vehicle speed sensor (VSS). The scan tool will display a higher value at higher vehicle speeds, and a lower value at lower vehicle speeds.

Warm-ups w/o Emission Faults
- The scan tool displays a range of 0-255. This parameter counts the number of warm up cycles without an emission fault present. The counter increments to 255 and rolls back to 0 unless a fault occurs. If a fault occurs, the counter reverts back to 0 until the fault is corrected. Clearing the information with a scan tool or a loss of power to the PCM also resets the counter to 0. The scan tool displays counts. This display indicates the number of warm-up cycles without a emission failure.

Warm-ups w/o Non-Emission Faults
- The scan tool displays a range of 0-255. This parameter counts the number of warm up cycles without a non-emission fault present. The counter increments to 255 and rolls back to 0 unless a fault occurs. If a fault occurs, the counter reverts back to 0 until the fault is corrected. Clearing information with a scan tool or a loss of power to the PCM also resets the counter to 0.