Operation CHARM: Car repair manuals for everyone.

Part 2



Scan Tool Data Definitions

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 tank pressure as calculated based on a signal sent to the control module from the fuel tank pressure (FTP) sensor. The scan tool will display a low value when the pressure in the fuel tank is low or a vacuum. The scan tool will display a high value when the pressure in the fuel tank is high.

Fuel Rail Pressure Sensor
- This parameter displays the voltage signal sent to the control module from the sensor used to monitor the pressure inside the fuel tank. The scan tool will display a low voltage when the pressure in the fuel tank is high. The scan tool will display a high voltage when the pressure in the fuel tank is low or in a vacuum.

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.