A/C - F

The Engine Scan Tool Data Definitions contains a brief description of all engine related parameters available on the scan tool. The list is 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 Clutch Feed Back Signal: This parameter displays the state of the air conditioning (A/C) compressor clutch based on the signal from the switched side of the A/C clutch relay. The scan tool will display Relay On or Relay Off. Relay On indicates the A/C clutch relay has closed, allowing voltage to the A/C compressor clutch. Relay Off indicates the A/C clutch relay is open and the A/C compressor clutch is not engaged.

A/C Compressor Cycling Switch: This parameter displays the state of the air conditioning (A/C) compressor cycling switch as determined by the control module. The scan tool will display Normal or Low Pressure. Normal indicates the A/C system has enough refrigerant to close the A/C compressor cycling switch, allowing the A/C compressor to engage. Low Pressure indicates the A/C refrigerant system has low pressure and the A/C compressor cycling switch is open.

A/C Sec. High Pressure Switch: The scan tool displays High Pressure or Normal. This parameter displays the state of the A/C secondary high pressure switch. The A/C secondary high pressure switch is normally open.

A/C Relay Command: This parameter displays the commanded state of the air conditioning (A/C) clutch relay control circuit. The scan tool will display ON or OFF. ON indicates the A/C clutch relay control circuit is being grounded by the control module, alllowing voltage to the A/C compressor clutch. OFF indicates the A/C clutch relay is not being commanded on 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. The scan tool will display Yes or No. Yes indicates the control module is receiving a request from the HVAC system to ground the A/C clutch relay control circuit, engaging the A/C compressor clutch. No indicates the control module is not receiving a request from the HVAC system to ground the A/C clutch relay control circuit.

AIR Relay Command: This parameter displays the commanded state of the secondary air injection (AIR) pump relay control circuit. The scan tool will display ON or OFF. ON indicates the AIR pump relay control circuit is being grounded by the control module, allowing voltage to the AIR pump. OFF indicates the AIR pump relay is not being commanded on by the control module.

APP Average: This parameter displays the average of the 3 accelerator pedal position (APP) sensors as calculated by the throttle actuator control (TAC) module. The APP average is a range of values indicating a low number when the accelerator pedal is not depressed to a high number when the accelerator pedal is fully depressed. This value is listed in counts.

APP Indicated Angle: This parameter displays the angle of the accelerator pedal as calculated by the control module using the signals from the accelerator pedal position sensors. The APP indicated angle is a range of values indicating a low percentage when the accelerator pedal is not depressed to a high percentage when the accelerator pedal is fully depressed.

APP Sensor 1: This parameter displays the angle of the accelerator pedal position (APP) sensor 1 as calculated by the control module using the signal from the APP sensor 1. APP sensor 1 is a range of values indicating a low percentage when the accelerator pedal is not depressed to a high percentage when the accelerator pedal is fully depressed.

APP Sensor 1: This parameter displays the voltage signal sent to the control module from accelerator pedal position (APP) sensor 1 of the APP sensor assembly. APP sensor 1 is a range of values indicating a low voltage when the accelerator pedal is not depressed to a high voltage when the accelerator pedal is fully depressed.

APP Sensor 1 and 2: This parameter displays the results of a control module test that compares the signals from the accelerator pedal position (APP) sensors 1 and 2. The scan tool will display Agree or Disagree. Agree indicates that APP sensor 1 and APP sensor 2 voltages correspond to the same accelerator pedal position. Disagree indicates that APP sensor 1 and APP sensor 2 voltages correspond to different accelerator pedal positions.

APP Sensor 2: This parameter displays the angle of the accelerator pedal position (APP) sensor 2 as calculated by the control module using the signal from the APP sensor 2. APP sensor 2 is a range of values indicating a low percentage when the accelerator pedal is not depressed to a high percentage when the accelerator pedal is fully depressed.

APP Sensor 2: This parameter displays the voltage signal sent to the control module from accelerator pedal position (APP) sensor 2 of the APP sensor assembly. APP sensor 2 is a range of values indicating a low voltage when the accelerator pedal is not depressed to a high voltage when the accelerator pedal is fully depressed.

BARO: The scan tool displays a range of 10-105 kPa. The barometric pressure (BARO) reading is determined from the manifold absolute pressure (MAP) sensor signal. The powertrain control module (PCM) monitors the MAP signal during key up or wide open throttle (WOT) conditions. The barometric pressure (BARO) compensates for altitude differences.

CMP Sensor-High to Low: The scan tool displays 0-65,535 counts. The counts increment as the powertrain control module (PCM) detects the camshaft position (CMP) sensor signal voltage going from high to low.

CMP Sensor-Low to High: The scan tool displays 0-65,535 counts. The counts increment as the powertrain control module (PCM) detects the camshaft position (CMP) signal voltage going from low to high.

Cold Start Up: The scan tool displays Yes or No. A cold start-up is when the engine coolant temperature (ECT) rises above a predetermined temperature during an ignition cycle. The next ignition cycle the ECT should be below a predetermined temperature. Also the ECT and the intake air temperature (IAT) are less than 50°C (122°F) and are within 3°C (5°F) of each other at start-up. When the above is true, the scan tool displays Yes.

Coolant Level Switch: The scan tool displays OK or Low. This parameter indicates when the engine coolant level is low. The scan tool displays Low when the powertrain control module (PCM) detects the engine coolant level is low.

Cruise Control Active: The scan tool displays Yes or No. When the cruise control switch is ON and the set/coast switch is activated, the scan tool displays yes. When the cruise control switch is ON and the set/coast switch is released, the scan tool displays No.

Cruise Disengage 1-8 History: This parameter displays the last 8 cruise control disengages in order from 1 to 8. The control module will disengage the cruise control for up to 20 different conditions.

Cruise On/Off Switch: The scan tool displays ON or OFF. When you activate the cruise control switch, the scan tool displays ON. The switch, when in the ON position, sends a signal voltage to the throttle actuator control (TAC) module. This allows all other functions of the cruise control. When you turn OFF the cruise control switch, the scan tool displays OFF.

Cruise Release Brake Pedal Switch: This parameter displays the state of the Cruise Release Brake Pedal Switch as determined by the control module. The scan tool will display Released or Applied. Released indicates the brake pedal is not being pushed down, allowing the cruise control to be enabled. Applied indicates the brake switch is being applied, disabling cruise control operation.

Cruise Resume/Accel: The scan tool displays ON or OFF. When the cruise control switch is in the ON position and the Resume/Accel switch is activated, the scan tool displays ON. When the Resume/Accel switch is released, the scan tool displays OFF.

Cruise Set/Coast: The scan tool displays ON or OFF. When the cruise control switch is in the ON position and the Set/Coast switch is activated, the scan tool displays ON. When the Set/Coast switch is released the scan tool displays OFF.

Current Gear: The scan tool displays 0-4. The scan tool displays which gear the transmission is in. An illegal transmission position displays 9.

Cycles of Misfire Data: The scan tool displays a range of 0-100. The powertrain control module (PCM) counts the number of misfire tests during 200 engine revolutions.

Decel. Fuel Shutoff: The scan tool displays Active or Inactive. The scan tool displays Active when the powertrain control module (PCM) shuts off fuel flow through the fuel injectors because of a deceleration condition.

Desired EGR Position: The scan tool displays 0-100 percent. This parameter displays the desired position of the exhaust gas recirculation (EGR) pintle as requested by the powertrain control module (PCM). This parameter should be very close to actual EGR position.

Desired EGR Position: The scan tool displays 0-5 volts. The commanded exhaust gas recirculation (EGR) is the EGR pintle position commanded by the powertrain control module (PCM).

Desired Idle Speed: The scan tool displays a range of 0-3,187 RPM. The powertrain control module (PCM) commands the desired idle speed. The PCM compensates for various engine loads based on engine coolant temperature (ECT) in order to keep the engine at the desired speed.

DTC Set This Ignition: The scan tool displays Yes or No. This parameter indicates if a DTC set during the current ignition cycle.

ECT Sensor: The scan tool displays a range of -39 to +140°C (-38 to +284°F). The powertrain control module (PCM) applies 5 volts to the engine coolant temperature (ECT) sensor circuit. The sensor is a thermistor which changes internal resistance as the engine temperature changes. When the sensor is cold, internal resistance high, the PCM senses a high signal voltage and interprets the voltage as a cold engine. As the sensor warms, internal resistance decreases, the voltage signal decreases and the PCM interprets the lower voltage as a warm engine.

EGR Learned Minimum Position: Represents the learned voltage that the controller uses to determine whether or not the EGR valve is fully closed.

EGR Position Sensor: The scan tool displays 0-5 volts. This parameter displays the actual exhaust gas recirculation (EGR) pintle position in voltage.

EGR Position Sensor: The scan tool displays a range of 0-100 percent. The powertrain control module (PCM) supplies a pulse width modulated (PWM) duty cycle to control the exhaust gas recirculation (EGR) valve. Zero percent indicates no EGR flow. One hundred percent indicates full EGR flow.

Engine Load: The scan tool displays a range of 0-100 percent. The powertrain control module (PCM) calculates the engine load from engine speed and mass airflow (MAF) sensor readings. The engine load increases with an increase in RPM or airflow.

Engine Oil Level Switch: The scan tool displays OK or Low. This parameter indicates when the engine oil level is low. The scan tool displays Low when the powertrain control module (PCM) detects the engine oil level is low.

Engine Oil Life Remaining: The scan tool displays 0-100 percent. This display represents the engine oil life index that is calculated and maintained by the powertrain control module (PCM).

Engine Run Time: The scan tool displays Hours, Minutes and Seconds. This displays the amount of engine run time for the current ignition cycle. When you cycle the ignition OFF, the timer resets to zero.

Engine Speed: The scan tool displays a range of 0-10,000 RPM. The powertrain control module (PCM) computes engine speed from the ignition reference pulses. The engine speed should remain close to desired idle under various engine loads with the engine idling.

EVAP Purge Solenoid Command: The scan tool displays a range of 0-100 percent. The powertrain control module (PCM) supplies a pulse width modulated (PWM) duty cycle to control the evaporative emission (EVAP) purge solenoid valve. 0 percent indicates no purge. 100 percent indicates full purge.

EVAP Test Result: The scan tool displays if the evaporative emission (EVAP) test has passed or failed. The scan tool displays pass when the powertrain control module (PCM) determines that the EVAP diagnostic has passed. The scan tool displays fail when the PCM determines that the EVAP diagnostic has failed.

EVAP Vent Solenoid Command: The scan tool displays Venting or Not Venting. The evaporative emission (EVAP) canister vent valve is normally open. The powertrain control module (PCM) commands the EVAP canister vent valve closed, during testing of the EVAP system.

Fuel Level Sensor: The scan tool displays 0-5 volts. The scan tool displays below 1 volt for an empty tank, and close to 2.5 volts for a full tank.

Fuel Level Sensor Rear Tank: The scan tool displays 0-5 volts. The scan tool displays below 1 volt for an empty tank, and close to 2.5 volts for a full tank.

Fuel Tank Level Remaining: The scan tool displays in liters or gallons the amount of fuel remaining in the fuel tank.

Fuel Tank Level Remaining: The scan tool displays 0-100 percent. The scan tool displays in percentage the amount of fuel remaining in the fuel tank.

Fuel Tank Pressure Sensor: The scan tool displays -32.7 to +13.96 mm/Hg (-17.4 to +7.5 in H2O. This parameter indicates the pressure vacuum inside of the fuel tank. A negative value indicates a vacuum. A positive value indicates a pressure.

Fuel Tank Pressure Sensor: The scan tool displays 0-5 volts. The scan tool displays in voltage the pressure inside of the fuel tank.

Fuel Tank Rated Capacity: The scan tool displays the capacity of the fuel tank in liters or gallons.

Fuel Trim Cell: The scan tool displays a range of 0-23. The powertrain control module (PCM) determines from the manifold absolute pressure (MAP) and RPM inputs which fuel trim cell to operate the engine in. The fuel trim cell displayed on the scan tool is the cell that the engine is operating under.

Fuel Trim Learn: The scan tool displays Enabled or Disabled. When conditions are appropriate for enabling long term fuel trim corrections, the scan tool displays Enabled. This indicates that the long term fuel trim is responding to the 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.