The Engine Control Module Scan Tool Data Definitions contains a brief description of all engine control module (ECM) related parameters 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.

5 Volt Reference 1 Circuit: This parameter displays the voltage sensed on the 5-volt reference 1 circuit at the control module. The scan tool will display a higher value at higher voltage. The scan tool will display a lower value at lower voltage.

5 Volt Reference 2 Circuit: This parameter displays the voltage sensed on the 5-volt reference 2 circuit at the control module. The scan tool will display a higher value at higher voltage. The scan tool will display a lower value at lower voltage.

5 Volt Reference 3 Circuit: This parameter displays the voltage sensed on the 5-volt reference 3 circuit at the control module. The scan tool will display a higher value at higher voltage. The scan tool will display a lower value at lower voltage.

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, allowing voltage to the A/C compressor clutch. OFF indicates the A/C clutch relay is not being commanded on by the control module.

Ambient Air Temperature: This parameter displays the temperature of the ambient air as calculated by the control module based on the input from the ambient air temperature sensor. The scan tool will display a low value when the air temperature is low, and a high value when the air temperature is high.

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 accelerator pedal position (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 voltage signal sent to the control module from 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: 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.

APP Sensor 1 Indicated Position: This parameter display the angle of the 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 2: This parameter displays the voltage signal sent to the control module from 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.

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.

APP Sensor 2 Indicated Position: This parameter displays the angle of the 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.

Balancing Rate Cyl. 1-8: These parameter display the adjustment in fuel volume for each cylinder as calculated by the control module. The scan tool will display a negative balancing rate if the fuel volume is lowered. The scan tool will display a positive balancing rate if the fuel volume is increased.

BARO: This parameter displays the barometric pressure as calculated by the control module using the signal from the barometric pressure (BARO) sensor. The scan tool will display a high value at higher barometric pressures, such as sea level. The scan tool will display a lower value at lower barometric pressures, such as higher altitude locations.

Base Injector Fuel Rate: It display base calculate rate fuel delivers. The rate is calculated in cubic millimeters.

CAM Signal Present: This parameter displays the state of the CAM signal as determined by the control module. The scan tool will display Yes if the CAM signal is being received by the control module. The scan tool will display No if the CAM signal is missing.

CKP Sensor Signal Present: This parameter displays an incrementing counter when the control module receives a signal from the crankshaft position (CKP) sensor. The scan tool will display an incrementing counter when the CKP signal is being received by the control module. The scan tool will display a steady number when the CKP signal is not being received by the control module.

Cmmd. A/F Equivalence Ratio: This parameter displays the ratio of air to fuel as calculated by the control module based on various sensor inputs. The scan tool will display a lower air fuel ratio when a richer air to fuel mixture is commanded. The scan tool will display a higher air fuel ratio when a leaner air to fuel mixture is commanded.

Coolant Level Switch: This parameter displays the level of engine coolant as determined by the control module. The control module determines the level of the coolant using the signal from a switch used to monitor the engine coolant level. The scan tool will display low when the engine coolant level is low. The scan tool will display OK when the coolant level is correct.

Cruise Control Active: This parameter displays the status of the cruise control system as determined by the control module. The scan tool will display Yes when the cruise control system is in control of vehicle speed. The scan tool will display No when the cruise control system is not operating.

Current Fuel Type: The parameter will display diesel as the current fuel type.

Desired EGR Position: This parameter displays the position of the exhaust gas recirculation (EGR) valve commanded by the control module. The scan tool will display 0 percent when the control module is commanding the EGR valve closed. The scan tool will display a higher percentage when the EGR valve is commanded open.

Desired Fuel Rail Pressure: This parameter displays the desired fuel rail pressure as calculated by the control module. This value is calculated based on engine speed, engine load, and sensor inputs. The scan tool will display a higher value at higher engine speeds and loads, and a lower value at idle.

Desired IAF Valve Position: This parameter will display the position of the intake air flow valve and it will display it in percentage.

Desired Idle Speed: This parameter displays the engine idle speed in RPM as commanded by the control module. The control module compensates for various engine loads in order to maintain the desired engine speed at idle. This parameter is not valid unless the engine is running.

Desired TC Vane Position: This parameter displays the position of the turbocharger vane position sensor as the turbocharger vane position is commanded by the control module. The scan tool will display 0 percent when the control module is commanding the vanes open. The scan tool will display a higher percentage when the vanes are commanded closed.

Des. TC Vane Pos. Ctrl. Solenoid: This parameter displays the desired current draw of the turbocharger vane position control solenoid valve as calculated by the control module. The scan tool will display a high value if the solenoid is commanded open, and a lower value when the solenoid is commanded closed.

Distance Since DTC Cleared: This parameter will display the amount of vehicle travel after a DTC has been cleared. This parameter will be displayed in km/miles.

Distance Since Last DPF Regeneration: This parameter will display the amount of vehicle travel after a DPF regeneration. This parameter will be displayed in km/miles.

DPF Indicator Command: This parameter will display the status of the IPC mounted DPF status light. This parameter will display On/Off.

DPF Pressure Sensor: This parameter will display the voltage differential between the front and rear pressures at the DPF as calculated by the ECM. This will be displayed in volts. As the DPF becomes restricted the differential pressure increases and the voltage we get higher.

DPF Regen Inhibit Reason: The parameter will display the reason why the DPF regeneration was inhibited. The parameter will display, None; Engine Run Time; ECT Too Low Eng. Oil temp; BARO Low; ECT Too High; Ign. Voltage; Not in Park; Trans. Range; VSS Engine Speed; Fuel Rate APP; EGT 1 Range; EGT 2 Range; Soot Mass; Fault; DPF Temperature; EGT 1 High; EGT 2 High ; Fault; Device Control; ECT too High; Decel Rate; Fuel Level Low; Turbo Temp; TCM; Idle Speed; MEC Counter; BPP Applied.

DPF Regenerations Completed: The parameter displays a count from 0 to 65535. Every time the regeneration has completed, this value is incremented.

DPF Regeneration Reason: This parameter will display the reason for the regen. The parameter will display, None; Fuel Used; Engine Run Time; Distance Traveled; Device Control; DPF Pressure; Soot Mass, Calc. Soot.

DPF Regeneration Status: This parameter will display the status of the regen. The parameter will display, Not Required; Regen Required; Regen Active; Device Control; Regen Complete.

DPF Soot Mass: This parameter displays the amount of calculated soot in exhaust particulate filter. This parameter will be displayed in grams.

EC Ignition Relay Command: This parameter displays the commanded state of the engine control (EC) ignition relay control circuit. The scan tool will display ON or OFF. ON indicates the EC ignition relay control circuit is being grounded by the control module, allowing voltage to other control module circuits and systems. OFF indicates the EC ignition relay is not being commanded ON by the control module.

ECT Sensor 1: This parameter displays the temperature of the engine coolant calculated by the control module, based on the input from the engine coolant temperature sensor. When the coolant temperature is low, the scan tool will display a low temperature. When the coolant temperature is high, the scan tool will display a high temperature.

ECT Sensor 2: This parameter displays the temperature of the engine coolant based on the input from the engine coolant temperature (ECT) sensor 2. When the coolant temperature is low, the scan tool will display a low temperature. When the coolant temperature is high, the scan tool will display a high temperature.

EGR Learn Minimum Position: This parameter will display the learned value of the EGR valve. This parameter will be displayed in a percentage.

EGR Position Sensor: This parameter displays the voltage signal received from the EGR valve position sensor by the control module. The scan tool will display a lower value when the EGR valve is closed, and a higher value when the EGR valve is open.

EGR Position Sensor: This parameter displays EGR valve position as calculated by the control module based on an input from the EGR valve position sensor. The scan tool will display a lower value when the EGR valve is closed, and a higher value when the EGR valve is open.

EGR Position Variance: This parameter displays the difference between the desired EGR valve position calculated by the control module and the actual EGR position input from the EGR valve position sensor. The scan tool will display a higher value if the difference is large, and a lower value if the difference is small.

EGR Solenoid Command: This parameter displays the duty cycle commanded by the control module for the EGR valve. The scan tool will display a high percentage when the EGR valve is commanded open. The scan tool will display a low percentage when the EGR valve is commanded closed.

EGT Sensor 1: This parameter will display the exhaust temperature before the DPF. When the exhaust temperature is low, the scan tool will display a low temperature. When the exhaust temperature is high, the scan tool will display a high temperature.

EGT Sensor 2: This parameter will display the exhaust temperature after the DPF. When the exhaust temperature is low, the scan tool will display a low temperature. When the exhaust temperature is high, the scan tool will display a high temperature.

Engine Load: This parameter displays the engine load in percent based on inputs to the control module from the various engine sensors. The scan tool will display a low percentage when the engine is at idle with little or no load. The scan tool will display a high percentage when the engine is running at a high RPM under a heavy load.

Engine Oil Life Remaining: This parameter displays the amount engine oil life remaining before requiring an oil change based on calculations by the control module. The scan tool will display lower values as the engine oil life approaches 0 miles.

Engine Oil Pressure Sensor: This parameter displays the pressure of the engine oil as calculated by the control module using a signal from the engine oil pressure (EOP) sensor. The scan tool will display oil pressure when the engine is running. The engine oil pressure sensor has a range of values indicating a low value when the oil pressure is low to a high value when the oil pressure is high.

Engine Run Time: This parameter displays the time elapsed since the engine was started. The scan tool will display the time in hours, minutes and seconds. The engine run time will reset to zero when the engine stops running.

Engine Run Time Since Last DPF Regeneration: This parameter displays the total of time since the last regen. This parameter will be displayed in hours, minutes and seconds.

Engine Speed: This parameter displays the speed of the crankshaft as determined by the control module using an input from the CKP sensor. The scan tool will display a high value at high engine speeds and a low value at low engine speeds.

FRP Regulator Command: This parameter displays the fuel rail pressure regulator duty cycle as commanded by the control module. The scan tool will display a lower value for a higher commanded fuel pressure, and a higher value for a lower commanded fuel pressure.

Fuel Level Sensor: This parameter displays the approximate fuel level in the fuel tank as calculated by the control module based on inputs from the fuel level sensors. The scan tool will display a low value when the fuel level in the tank is low or near empty. The scan tool will display a high value when the fuel level in the tank is high or near full.

Fuel Pump Relay Command: This parameter displays the commanded value of the fuel pump relay. This function is not available on all application.

Fuel Rail Pressure Sensor: This parameter displays the fuel rail pressure as calculated based on a signal sent to the control module from the fuel rail pressure (FRP) sensor. The scan tool will display a low pressure at idle and a high pressure when fuel pressure demands are high.

Fuel Rail Pressure Sensor: This parameter displays the voltage signal sent to the control module from the sensor used to monitor the fuel rail pressure. The scan tool will display a low voltage when the engine is at idle. The scan tool will display a high voltage when pressure demands are high.

Fuel Tank Level Remaining: This parameter displays the amount of fuel remaining in the fuel tank as measured in percent. The control module determines the amount of fuel remaining in the tank by using information from the fuel level sensor(s). The scan tool will display a higher value with a full fuel tank, and a lower value with an empty fuel tank.

Fuel Temperature Sensor: This parameter displays the current fuel temperature as calculated by the control module based on input from the fuel temperature sensor. The scan tool will display a higher value at higher fuel temperatures. The scan tool will display a lower value at lower fuel temperatures.

Fuel Used Since Last DPF Regeneration: This parameter will display the amount of fuel used since last regeneration of the exhaust particulate filter.

Glow Plug Command: This parameter displays the voltage supply to the glow plugs as measured by the control module. The scan tool will display a higher value at high voltages, or a lower value at lower voltages.

Glow Plug 1-8: This parameter indicates the resistance of the individual glow plug circuits as calculated by the control module. The scan tool will display a higher value for more resistance, and a lower value for less resistance.

Glow Plug Driver Open: This parameter displays the diagnostic state of the output driver for the glow plug circuits. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an open on the circuit.

Glow Plug Driver Shorted: This parameter displays the diagnostic state of the output driver for the glow plug circuits. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an short on the circuit.

Glow Plug Overtemp: This parameter displays the diagnostic state of the output driver for the intake air heater (IAH). The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if the circuit is shorted to ground.

Glow Plug Overvoltage: This parameter displays the diagnostic state of the output driver for the glow plug circuits. The scan tool will display OK if the circuits are operating correctly. The scan tool will display Fault if the control module detects that the glow plug voltage is too high.

Glow Plug Undervoltage: This parameter displays the diagnostic state of the output driver for the glow plug circuits. The scan tool will display OK if the circuits are operating correctly. The scan tool will display Fault if the control module detects that the glow plug voltage is too low.

High Idle Switch: This parameter displays the state of the high idle request input to the control module from the high idle switch. The scan tool will display ON or OFF. ON indicates the control module is receiving a request from the high idle switch to increase engine speed. OFF indicates the control module is not receiving a request from the high idle switch to increase engine speed.

IAF Valve Learned Minimum: This parameter displays the learned value of the intake air flow valve. This value will be displayed in percent.

IAF Value Position: This parameter displays the actual position of the intake air flow valve.

IAF Valve Pos. Sensor: This parameter displays the voltage signal sent to the control module from the intake air valve. The intake air valve is a range of values indicating a high voltage when the throttle is closed to a low voltage when the throttle plate is fully open.

IAT Sensor 1: This parameter displays the temperature of the air entering the engine air duct as calculated by the control module based on the input from the intake air temperature 1 sensor. The scan tool will display a low value when the air temperature is low, and a high value when the air temperature is high.

IAT Sensor 2: This parameter displays the temperature of the air entering the engine intake manifold as calculated by the control module based on the input from the intake air temperature 2 sensor. The scan tool will display a low value when the air temperature is low, and a high value when the air temperature is high.

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. The scan tool will display a low value when the voltage is low. The scan tool will display a high value, such as battery voltage, when the voltage is higher.

Ignition Accessory Signal: This parameter displays the state of the ignition 0 input to the control module from the ignition switch. The scan tool will display ON when the ignition switch is in the ignition 0 position. The scan tool will display OFF when the ignition switch is in any other position.

Injection Pump Cam Reference Signal Missed: This parameter will display the number of reference signals missed.

Injection Timing: Indicates the current timing of the main injection pulse as calculated by the control module. The scan tool will display a higher value for a main injection event farther from top dead center (TDC). The Scan tool will display a lower value for a main injection event closer to TDC.

Intake Air Heater Command: This parameter displays duty cycle of the IAH as commanded by the control module.

Intake Air Heater Command: This parameter displays the status of the IAH as commanded by the control module.

MAF Sensor: This parameter indicates the frequency signal received from the MAF sensor by the control module. The scan tool will display a high value at high engine speeds, and a low value at low engine speeds.

Main Injection Timing: Indicates the current timing of the main injection pulse as calculated by the control module. The scan tool will display a higher value for a main injection event farther from top dead center (TDC). The Scan tool will display a lower value for a main injection event closer to TDC.

MAP Sensor: This parameter indicates the voltage signal received by the control module from the MAP sensor. The scan tool displays a low voltage at idle, and a high voltage at wide open throttle. Barometric pressure and altitude can effect these values.

Misfire Current Cyl. #1-8: This parameter displays the number of possible misfires during cylinder firing events detected on each cylinder as calculated by the control module. The misfires are calculated based on engine crankshaft rotation speed variations. The scan tool displays an incrementing counter.

Particulate Filt. Pressure Variance: This parameter will display the pressure differential between the front and rear pressures at the DPF as calculated by the ECM. This will be displayed in kPa. As the DPF becomes restricted the differential pressure will increase.

Pilot Inj. Cyl 1-8 Command: This parameter displays the commanded on time of the fuel injectors for the pilot injection pulse. The scan tool will display a higher value for a longer injection pulse. The scan tool will display a lower value for a shorter injection pulse.

PNP Switch: This parameter indicates the range selection of the automatic transmission as calculated by the control module based on input from the park/neutral position (PNP) switch. The scan tool will display, In Gear, Park, or Neutral depending on the PNP switch position.

Reduced Engine Power: This parameter will display the fuel system status as commanded by the ECM.

Start Up ECT: This parameter Indicates the engine coolant temperature at engine start up as calculated by the control module based on the signal from the engine coolant temperature (ECT) sensor. the scan tool will display a higher value on a warmer engine, and a lower value on a colder engine.

Start Up Fuel Temperature: This parameter Indicates the fuel temperature at engine start up as calculated by the control module based on the signal from the fuel temperature (ECT) sensor. The scan tool will display a higher value on a warmer fuel, and a lower value on a colder fuel.

Start Up IAT: This parameter indicates the intake air temperature at engine start up as calculated by the control module based on the signal from the intake air temperature (IAT) sensor. the scan tool will display a higher value during warmer underhood temperatures, and a lower value during colder underhood temperatures.

TC Vane Position Lrn. This Run Cycle: This parameter indicates the status of the control module in learning the turbocharger vane position. The Scan tool will display Yes if the turbocharger vane position has been learned this ignition cycle. The scan tool will display No if the turbocharger vane position has not been learned this ignition cycle. The control module will attempt to relearn during every ignition cycle. A relearn must be completed after any service on the turbocharger or control module.

TC Vane Position Lrn. Since DTC Clear: This parameter indicates the status of the control module in learning the turbocharger vane position. The Scan tool will display Yes if the turbocharger vane position has been learned any time after the DTCs have been cleared. The scan tool will display No if the turbocharger vane position has not been learned since the last DTC clear. The control module will attempt to relearn during every ignition cycle. A relearn must be completed after any service on the turbocharger or control module.

TC Vane Position Sensor: This parameter displays the current commanded state of the turbocharger vane position control solenoid valve by the control module. The scan tool will display a higher value as the solenoid is commanded open. The scan tool will display a lower value as the solenoid is commanded closed.

TC Vane Position Sensor: This parameter displays the voltage signal sent to the control module from the sensor. The scan tool will display a higher value as the solenoid is commanded open. The scan tool will display a lower value as the solenoid is commanded closed.

TC Vane Pos. Ctrl. Solenoid: This parameter displays the current draw of the vane position control solenoid through the control module. The scan tool will display a high current draw when the turbocharger vanes are being commanded closed. The scan tool will display a lower current draw when the turbocharger vanes are being commanded open.

TCC/Cruise Brake Pedal Switch: This parameter displays the state of the brake pedal as determined by the control module. The control module monitors the pedal switch on the brake pedal for vehicles equipped with an automatic transmission. The control module uses this information to release the torque convertor clutch when the brake pedal is applied. The scan tool will display Applied when the brake pedal is depressed. the scan tool will display Released when the brake pedal is not applied.

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.

Water in Fuel Sensor: This parameter will display Water if fuel is present in the fuel or No Water when water is no longer present in the fuel.