The Scan Tool Data Definitions list contains a brief description of all of the engine related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists. In some cases the parameter may appear more than once, or in more than one data list in order to group certain related parameters together.

A/C Disengage 1-8 History: The parameter displays the last 8 air conditioning (A/C) compressor disengages in order from 1 to 8 with 8 being the most recent. There are about 8 possible causes for the A/C compressor to disengage.

A/C High Side Pressure Sensor: This parameter displays the voltage from the A/C high side pressure sensor signal circuit to the control module.

A/C OFF for WOT: This parameter displays whether the control module is commanding the air conditioning (A/C) compressor clutch relay off for wide open throttle (WOT).

A/C Pressure Disable: This parameter displays whether the air conditioning (A/C) pressure is out of range for normal operation as determined by the control module.

A/C Relay Circuit Status:  This parameter displays the state of the air conditioning (A/C) clutch relay control circuit. The parameter displays Fault if the A/C clutch relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON. This parameter may not change if the scan tool is used to command the A/C relay ON.

A/C Relay Command: This parameter displays the state of the air conditioning (A/C) clutch relay control circuit as commanded by the control module.

A/C Request Signal: This parameter displays the state of the air conditioning (A/C) request input to the control module from the heating, ventilation, and air conditioning (HVAC) controls.

APP Indicated Angle: This parameter displays the angle of the accelerator pedal position (APP) as calculated by the control module using the signals from the APP sensors.

APP Sensor 1: This parameter displays the actual voltage on the accelerator pedal position (APP) sensor 1 signal circuit as measured by the control module.

APP Sensor 2: This parameter displays the actual voltage on the accelerator pedal position (APP) sensor 2 signal circuit as measured by the control module.

APP Sensor 1 and 2: This parameter displays Disagree if the control module detects the signal voltage from the accelerator pedal position (APP) sensor 1 is not in correct relationship to APP sensor 2. The scan tool displays Agree under the normal operating conditions.

BARO: This parameter displays the barometric pressure (BARO). The control module uses the BARO for fuel control to compensate for altitude differences.

Brake Pedal Signal Status: This parameter displays the serial data message of the brake signal from the electronic brake and traction control module (EBTCM).

Calculated ECT - Closed Loop Fuel Control: This parameter displays the modeled temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined amount of time, a DTC will set.

Calculated ECT - Thermostat Diagnosis: This parameter displays the modeled temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined amount of time, a DTC will set.

Catalytic Converter Protection Active: This parameter displays if the control module is commanding catalytic converter protection.

Crank Request: This parameter displays whether the ignition switch has been cycled to the crank position requesting the control module to activate the starter relay.

Cruise Control Active: This parameter displays the status of the cruise control system as determined by the control module.

Cruise Disengage 1-8 History: The parameter displays the last 8 cruise control disengages in order from 1 to 8, with 8 being the most recent. There are about 33 possible causes for the cruise control to disengage.

Cruise Inhibited: This parameter displays Yes if the cruise control is disabled for any reason.

Cruise Inhibit Reason: This parameter displays the reason that cruise is inhibited.

Cruise On/Off Switch: This parameter displays the state of the cruise control on/off switch input to the control module.

Cruise Resume/Accel. Switch: This parameter displays the state of the cruise controls resume/accel switch position input to the control module.

Cruise Set/Coast Switch: This parameter displays the state of the cruise controls set/coast switch position input to the control module.

Current Gear: This parameter displays the transmission gear commanded by the transmission control module.

Current Gear Signal: This parameter displays Invalid if the serial data message from the transmission control module (TCM) is invalid.

Cycles of Misfire Data: This parameter displays the number of misfire tests during 200 engine revolutions.

Cylinder 1-6 Injector Circuit Status:  This parameter displays the state of the fuel injector control circuit. The parameter displays Fault if the fuel injector control circuit is open, shorted to ground, or shorted to voltage. This parameter displays indeterminate until the control circuit has been commanded ON. This parameter may not change if the scan tool is used to command the injector control circuit ON.

Cylinder 1-6 Knock Retard: This parameter displays the knock retard as commanded by the control module for cylinders 1-6. Each cylinder is controlled individually based on both knock sensor signal inputs.

Decel. Fuel Cutoff: This parameter displays the status of the operating mode of the control module used to turn off the fuel injectors and the evaporative emission (EVAP) canister purge valve during certain deceleration conditions.

Desired Exh. CMP Bank 1 or 2: This parameter displays the desired exhaust camshaft angle as commanded by the control module.

Desired HO2S Bank 1 or 2 Sensor 1: This parameter displays the desired heated oxygen sensor (HO2S) lambda value as commanded by the control module.

Desired Idle Speed: This parameter displays the desired engine idle speed as commanded by the control module.

Desired Int. CMP Bank 1 or 2: This parameter displays the desired intake camshaft angle as commanded by the control module.

DTC Set This Ignition : This parameter displays Yes if a DTC set on the current ignition cycle.

EC Ignition Relay Circuit Status:  This parameter displays the state of the EC Ignition Relay control circuit. The parameter displays Fault if the EC Ignition Relay control circuit is open, shorted to ground, or shorted to voltage.

EC Ignition Relay Command: This parameter displays the state of the control circuit for control module power relay as commanded by the control module.

EC Ignition Relay Feedback Signal: This parameter displays the voltage available at the EC ignition relay pin of the control module.

ECM Reset: This parameter displays Yes when an internal control module reset occurs. The scan tool displays NO under normal operating conditions.

ECT Sensor: This parameter displays the temperature of the engine coolant based on input to the control module from the engine coolant temperature (ECT) sensor.

Engine Load: This parameter displays the calculated engine load in percent based on inputs to the control module from various engine sensors.

Engine Off EVAP Test Conditions Met: This parameter displays Yes if the conditions for running the Engine Off evaporative (EVAP) diagnostic are met.

Engine Off Time: This parameter displays the amount of time that has elapsed since the engine was last cycled OFF.

Engine Oil Level Switch: This parameter displays if the level of the engine oil is within range as determined by the control module from information received from the engine oil level switch.

Engine Oil Pressure Sensor: This parameter displays OK if the engine oil pressure is within the correct range. If the control module detects that the engine oil pressure is not within the correct range, the scan tool displays Low.

Engine Oil Pressure Sensor: This parameter displays the engine oil pressure.

Engine Run Time: This parameter displays the time elapsed since the engine was started.

Engine Speed: This parameter displays the speed of the engine crankshaft rotation from information received from the crankshaft position (CKP) sensor. If there is a CKP sensor DTC, the ECM calculates the engine speed from one of the camshaft position (CMP) sensors.

EVAP Purge Solenoid Circuit Status:  This parameter displays the state of the evaporative emission (EVAP) purge solenoid control circuit. The parameter displays Fault if the EVAP purge solenoid control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON. This parameter may not change if the scan tool is used to command the EVAP purge solenoid ON.

EVAP Purge Solenoid Command: This parameter displays the on-time or duty cycle of the evaporative emission (EVAP) canister purge solenoid commanded by the control module. Zero percent indicates no purge. One hundred percent indicates full purge.

EVAP Vent Solenoid Circuit Status:  This parameter displays the state of the evaporative emission (EVAP) vent solenoid control circuit. The parameter displays Fault if the EVAP vent solenoid control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON. This parameter may not change if the scan tool is used to command the EVAP vent solenoid ON.

EVAP Vent Solenoid Command: This parameter displays the state of the control circuit for evaporative emission (EVAP) vent solenoid as commanded by the control module.

Exh. CMP Angle Bank 1 or 2: This parameter displays the actual exhaust camshaft position in degrees.

Exh. CMP Bank 1 or 2 Command: This parameter displays the exhaust camshaft position in percent of range as commanded by the control module.

Exh. CMP Solenoid Bn. 1 or 2 Circuit Status:  This parameter displays the state of the exhaust camshaft actuator solenoid control circuit. The parameter displays Fault if the camshaft actuator solenoid control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON. This parameter may not change if the scan tool is used to command the camshaft position (CMP) solenoid ON.

Extended Travel Brake Pedal Switch: This parameter displays the state of the brake pedal as determined by the control module from the extended travel brake pedal switch position.

FC Relay 1 Circuit Status:  This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON. This parameter may not change if the scan tool is used to command the FC relay ON.

FC Relay 1 Command: This parameter displays the control module commanded state of the fan relay control circuit.

FC Relays 2 and 3 Command: This parameter displays the control module commanded state of the fan relay control circuit.

FC Relays 2 and 3 Circuit Status:  This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the relay control circuit has been commanded ON. This parameter may not change if the scan tool is used to command the FC relay ON.

Fuel Level Sensor Left Tank (Secondary): This parameter displays the voltage signal received by the control module from the left or secondary fuel level sensor.

Fuel Level Sensor Right Tank (Primary): This parameter displays the voltage signal received by the control module from the right or primary fuel level sensor.

Fuel Pump Relay Circuit Status:  This parameter displays the state of the fuel pump relay control circuit. The parameter displays Fault if the fuel pump relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON. This parameter may not change if the scan tool is used to command the FP relay control circuit ON.

Fuel Pump Relay Command: This parameter displays the control modules commanded state of the fuel pump relay control circuit.

Fuel Tank Level Remaining: This parameter displays the amount of fuel in liters/gallons that remains in the fuel tank as determined by the control module from information received from the left and right fuel level sensors.

Fuel Tank Pressure Sensor: This parameter displays the pressure/vacuum inside the fuel tank. A negative value indicates a vacuum, while a positive value indicates a pressure.

Fuel Tank Pressure Sensor: This parameter displays the voltage signal received by the control module from the fuel tank pressure (FTP) sensor.

Fuel Tank Rated Capacity: This parameter displays the capacity of the fuel tank in liters or gallons.

Fuel Trim Learn: This parameter displays Enabled when conditions are appropriate for enabling long term fuel trim corrections. This indicates that the long term fuel trim is adapting continuing amounts of short term fuel trim. If the scan tool displays Disabled, then long term fuel trim will not respond to changes in short term fuel trim.

GEN L-Terminal Command: This parameter displays the control modules commanded state of the voltage regulator on the generator.

Generator F-Terminal Signal: This parameter displays the amount of generator on-time as commanded by the control module. The higher the percentage the greater the generator output.

HO2S Bank 1 or 2 Sensor 1: This parameter displays the lambda output from the heated oxygen sensor (HO2S) to the control module. A lambda below 1.0 indicates a rich exhaust, while a lambda above 1.0 indicates a lean exhaust.

HO2S Bank 1 or 2 Sensor 2: This parameter displays the voltage output from the heated oxygen sensor (HO2S) to the control module. A lower voltage indicates a lean exhaust, while a higher voltage indicates a rich exhaust.

HO2S Htr. Bn. 1 or 2 Sensor 1 or 2 Circuit Status:  This parameter displays the state of the oxygen sensor heater control circuit. The parameter displays Fault if the oxygen sensor heater control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON.

HO2S Htr. Bn. 1 or 2 Sensor 1 Command: This parameter displays the commanded state of the heater control circuit as commanded by the control module.

HO2S Sensing Element Bn. 1 or 2 Sensor 1: This parameter displays the resistance of the sensing element within the control module. The front sensors are normally regulated to 80 ohms.

IAT Sensor: This parameter displays the temperature of the air entering the air induction system based on input to the control module from the intake air temperature (IAT) sensor.

Ignition 0 Signal: This parameter displays On when the control module detects a voltage at the ignition 0 input terminal.

Ignition 1 Signal: This parameter displays On when the control module detects a voltage at the ignition 1 input terminal.

IMRC Solenoid Circuit Status:  This parameter displays the state of the intake manifold runner control (IMRC) control circuit. The parameter displays Fault if the IMRC control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON. This parameter may not change if the scan tool is used to command the IMRC solenoid ON.

IMRC Solenoid Command: This parameter displays the control modules commanded state of the intake manifold runner control (IMRC) solenoid.

Initial Brake Apply Signal: This parameter displays the state of the brake pedal that is transmitted over the serial data circuit from the electronic brake control module (EBCM).

Injector 1-6 Command: This parameter displays the amount of fuel injector ON time or pulse width as commanded by the control module.

Injector PWM Bank 1 or 2 Average: This parameter displays the average pulse width of the fuel injectors for each bank of the engine as determined by the control module.

Int. CMP Angle Bank 1 or 2: This parameter displays the actual intake camshaft position (CMP) in degrees.

Int. CMP Bank 1 or 2 Command: This parameter displays the intake camshaft position (CMP) in percent of range as commanded by the control module.

Int. CMP Solenoid Bn. 1 or 2 Circuit Status:  This parameter displays the state of the intake camshaft actuator solenoid control circuit. The parameter displays Fault if the camshaft actuator solenoid control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the circuit has been commanded ON. This parameter may not change if the scan tool is used to command the camshaft position (CMP) solenoid ON.

Knock Retard: This parameter indicates the amount of spark advance the control module removes from the ignition control (IC) spark advance in response to the signal from the knock sensors.

KS 1 or 2 Signal: This parameters displays the voltage input to the control module from the knock sensor (KS).

Loop Status Bn. 1 or 2 Sen. 1: This parameter displays the state of the fuel control system as commanded by the control module. Closed Loop operation indicates that the control module is controlling the fuel delivery based off the oxygen sensors input signal. In Open Loop operation the control module ignores the oxygen sensor input signal and bases the amount of fuel to be delivered on other sensor inputs.

Loop Status Bn. 1 or 2 Sen. 2: This parameter displays the state of the rear heated oxygen sensors (HO2S) as commanded by the control module. The rear sensors will not go into Closed Loop until the engine control module (ECM) determines that the HO2S is ready for operation.

LT FT Bn. 1 or Bn. 2 Cruise/Accel.: This parameter displays the commanded Long Term Fuel Trim correction by the control module for bank 1 or bank 2 for cruise and acceleration conditions.

LT FT Bn. 1 or Bn. 2 Idle/Decel.: This parameter displays the commanded Long Term Fuel Trim correction by the control module for bank 1 or bank 2 for idle and deceleration conditions.

MAF Sensor: This parameter displays the measured quantity of air flowing into the engine during all operating conditions.

MAF Sensor: This parameter displays the signal voltage from the mass air flow (MAF) sensor to the control module.

MIL Circuit Status:  This parameter displays the state of the malfunction indicator lamp (MIL) control circuit. The parameter displays Fault if the MIL control circuit is open, shorted to ground, or shorted to voltage. This parameter displays indeterminate until the circuit is commanded ON. This parameter may not change if the scan tool is used to command the MIL control circuit ON.

MIL Command: This parameter displays the commanded state of the malfunction indicator lamp (MIL) control circuit by the control module.

Mileage Since DTC Cleared: This parameter displays the mileage that has elapsed since any DTC has been cleared from the control modules memory.

Mileage Since First Failure: This parameter displays the mileage that has elapsed since the first emission failure.

Mileage Since Last Failure: This parameter displays the mileage that has elapsed since the last emission failure.

Mileage Since MIL Requested: This parameter displays the mileage that has elapsed since the control module has commanded the malfunction indicator lamp (MIL) On.

Misfire Current Cyl. 1-6: The scan tool displays a range of 0-200 counts. This parameter displays 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. 1-6: The scan tool displays a range of 0-65,535 counts. The misfire history counters display 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 DTC P0300 has become active. The misfire history counters will update every 200 cylinder firing events.

Moderate Brake Apply Signal: This parameter displays the state of the brake pedal that is transmitted over the serial data circuit from the electronic brake control module (EBCM).

PNP Switch: This parameter displays whether the transmission range selector is in PARK or NEUTRAL.

Power Enrichment: This parameter displays the status of the operating mode of the control module used to increase fuel delivery during certain acceleration conditions.

Reduced Engine Power: This parameter displays whether the control module is commanding reduced engine power due to a throttle actuator control (TAC) system condition.

Short Term FT Bank 1 or Bank 2: This parameter displays the short term correction to the fuel delivery by the control module in response to oxygen sensor 1 or 2. If the oxygen sensor indicates a lean air/fuel mixture, the control module will add fuel increasing the short term fuel trim above 0. If the oxygen sensor indicates a rich air/fuel mixture, the control module will reduce fuel decreasing the short term fuel trim below 0.

Spark: This parameter displays the amount of spark advance the control module is commanding on the ignition control circuits. The control module determines the desired advance.

Starter Relay Circuit Status:  This parameter displays the state of the starter relay control circuit. The parameter displays Fault if the starter relay control circuit is open, shorted to ground, or shorted to voltage. The parameter displays Indeterminate until the relay control circuit has been commanded ON. This parameter may not change if the scan tool is used to command the relay control circuit ON.

Starter Relay Command : This parameter displays the control modules commanded state of the starter motor relay control circuit.

Start Up ECT: This parameter displays the temperature of the engine coolant on start up based on input to the control module from the engine coolant temperature (ECT) sensor.

Start Up IAT: This parameter displays the temperature of the intake air at start in the air induction system based on input to the control module from the IAT sensor.

Stop Lamp Pedal Switch: This parameter displays the position of the stop lamp pedal switch input to the control module.

System Power Mode: This parameter displays the position of the ignition switch.

TAC System Learned Counts: This parameter displays the steps counted in learning the throttle actuator control parameters. The last step learned is 11.

Torque Delivered Signal: This is the calculated torque output from the engine to the transmission used by the electronic brake and traction control module (EBTCM) for the traction control system operation.

Torque Request Signal: The electronic brake and traction control module (EBTCM) sends a Desired Torque Level signal request to the control module. This decreases torque from the powertrain in order to reduce wheel slip during acceleration for the traction control.

Total Fuel Trim Avg. Bank 1 or Bank 2: This parameter displays the overall fuel trim from the idle/decel cell and the cruise/accel cell.

Total Misfire Count: This parameter displays the total number of cylinder firing events that the control module detected as misfires for the last 200 crankshaft revolution sample period.

TP Desired Angle: This parameter displays the desired throttle position (TP) angle commanded by the control module.

TP Indicated Angle: This parameter displays the percent of throttle opening as calculated by the control module using information from the two throttle position (TP) sensors.

TP Sensor 1: This parameter displays the actual voltage on the throttle position (TP) sensor 1 signal circuit as measured by the control module.

TP Sensor 1 Learned Min: This parameter displays the learned minimum value of throttle position (TP) sensor 1 as recorded by the control module during the last learn procedure.

TP Sensor 2: This parameter displays the actual voltage on the throttle position (TP) sensor 2 signal circuit as measured by the control module.

TP Sensor 2 Learned Min: This parameter displays the learned minimum value of throttle position (TP) sensor 2 as recorded by the control module during the last learn procedure.

TP Sensor 1 and 2: This parameter displays Disagree when the control module detects that throttle position (TP) sensor 1 voltage signal is not within the correct relationship to TP sensor 2. The scan tool displays Agree under the normal operating conditions.

Traction Control Status: This parameter displays Active if the electronic brake and traction control module (EBTCM) is commanding traction control.

Transmission Gear Selector Signal: This parameter displays the position of the transmission gear selector that is transmitted over the serial data circuit from the transmission control module (TCM).

TWC Temperature Calculated Bank 1 or Bank 2: This parameter displays the catalytic converter temperature as calculated by the control module.

Vehicle Security Status: This parameter displays the status of the vehicle theft deterrent system.

Vehicle Speed: This parameter displays the speed of the vehicle as calculated by the transmission control module (TCM) from information received from the vehicle speed sensor (VSS).

Volumetric Efficiency: This parameter displays the calculated volumetric efficiency of the engine as calculated by the control module.