A list of each data message displayed on the Scan tool
will be explained in two groups; Engine or Transmission. This information
will assist in emission or driveability problems. The displays can be viewed
while the vehicle is being driven. Always perform the Powertrain On-Board
Diagnostic (OBD) System Check first. The OBD System Check will confirm proper
system operation.
Engine Speed-Range 0-9999 RPM: Engine speed is computed by the PCM from the crankshaft position sensor.
If the crankshaft position sensor is inoperative, an rpm reading is taken
from the injection pump cam signal. It should remain close to desired idle
under various engine loads with engine idling. Engine speed value is very
accurate.
Desired Idle-Range 0-3187 RPM: The idle speed that is requested by the PCM. The PCM will compensate
for various engine loads based on engine coolant temperature to keep the engine
at the desired speed.
ECT-Range -40°C to 151°C, -40°F to 304°F: The Engine Coolant Temperature (ECT) sensor sends a signal to the PCM
relative to engine coolant temperature. The sensor is a thermistor which changes
internal resistance as temperature changes. When the sensor is cold (internal
resistance high), the PCM monitors a high signal voltage and interprets it
as a cold engine. As the sensor warms (internal resistance decreases), the
voltage signal will decrease and the PCM will interpret the lower voltage
as a warm engine.
Startup Coolant - Range -40°C to 151°C, -40°F
to 304°F: A reading of the vehicles coolant temperature at startup. This will change
every key cycle.
IAT-Range -40°C to 151°C, -40°F to 304°F: The intake air temperature sensor sends a signal to the PCM relative
to the incoming air. The IAT is used by the PCM to adjust fuel delivery.
ECT Sensor-Range 0-5 volts: The Engine Coolant Temperature (ECT) sensor sends a signal to the PCM
relative to engine coolant temperature. The sensor is a thermistor which changes
internal resistance as temperature changes. When the sensor is cold (internal
resistance high), the PCM monitors a high signal voltage and interprets it
as a cold engine. As the sensor warms (internal resistance decreases), the
voltage signal will decrease and the PCM will interpret the lower voltage
as a warm engine.
BARO-Range 10-105 kPa, 0-5 Volts: The BARO reading is determined from the Boost sensor at ignition ON,
engine OFF. The BARO reading display represents barometric pressure and is
used to compensate for altitude differences.
ESO Solenoid-Range ON/OFF: The ESO is located on the fuel injection pump. When the ignition switch
OFF, the ESO is in the NO FUEL position. It prevents fuel from entering the
fuel injection pump.
Boost Solenoid-Range 0-100%: The PCM cycles the boost solenoid PWM ON and OFF. The ON time (duty cycle)
of the solenoid valve is expressed as a percent. The Boost pulse width modulated
solenoid meters the vacuum level at the wastegate valve actuator as commanded
by the PCM.
Boost Pressure-Range 10-200 kPa, 0-5.0 Volts: The amount of turbo boost pressure in the intake manifold. This is measured
in kPa and volts. True boost pressure is determined by subtracting BARO from
the actual reading.
Actual EGR - Range 10-200 kPa, 0-5.0 Volts: Actual EGR vacuum going to the EGR valve.
Desired EGR - Range 10-200 kPa, 0-5.0 Volts: The PCM command for EGR vacuum.
EGR Duty Cycle-Range 0-100%: The PCM cycles the EGR solenoid PWM ON and OFF. The ON time (duty cycle)
of the EGR solenoid valve is expressed as a percent. The EGR pulse width modulated
solenoid meters the vacuum level at the EGR valve actuator as commanded by
the PCM.
Fuel Temp.-Range -28°C to 140°C, -18°F
to 285°F: There is a thermistor located in the optical sensor that determines fuel
temperature. When the sensor is cold (internal resistance high) the PCM monitors
a high signal voltage which it interprets as low fuel temperature. As the
sensor warms (internal resistance low) the voltage signal will decrease and
the PCM will interpret the low voltage as warm fuel.
Fuel Rate-Range 0-80mm3: This reading is displayed in millimeters cubed (mm3). This is the amount
of fuel the PCM is requesting.
Glow Plug-Range 0-25.5 volts: The amount of voltage the glow plug system is drawing. The scan tool
can be used to indicate if the glow plugs actually turned ON by monitoring
the voltage drop. Also, a good functional check of the glow plug relay.
Glow Plug System-Range ON/OFF: Glow Plug System-Range ON/OFF Indicates whether or not the PCM
has requested the glow plugs to be turned ON.
Des. Inj. Timing-Range 0-25.5 Degrees: The amount of injection timing requested by the PCM.
Act. Inj. Timing-Range 0-25.0 Degrees: Current actual injection timing.
APP Angle-Range 0-100%: Computed by the PCM from APP module voltage (throttle position) and should
display 0% at idle and 100% at wide open throttle.
APP 1-Range 0-5 Volts: The PCM uses the APP sensors to control fuel delivery as requested by
the driver. Three APP sensors are located in a module at the base of the accelerator
pedal. The PCM only requires information from one sensor, the other two serve
as fail safes. APP 1 should read about 0.35-0.95 volts at idle
to above 4.0 volts at wide open throttle.
APP 2-Range 0-5 Volts: The PCM uses the APP sensors to control fuel delivery as requested by
the driver. Three APP sensors are located in a module at the base of the accelerator
pedal. The PCM only requires information from one sensor, the other two serve
as fail safes. APP 2 should read about 4.5 volts at idle and steadily
decrease to about 1.0 volt at wide open throttle.
APP 3-Range 0-5 Volts: The PCM uses the APP sensors to control fuel delivery as requested by
the driver. Three APP sensors are located in a module at the base of the accelerator
pedal. The PCM only requires information from one sensor, the other two serve
as fail safes. APP 3 should read about 4.0 volts at idle and steadily
decrease to about 2.5 volts at wide open throttle.
Inj. Pump Sol. Closure Time-Range 0.0-4.0 milliseconds: Indicates the amount of time the fuel solenoid takes to close. When engine
load is increased, closure time will fluctuate.
TDC OFFSET-Range -2.50 to + 2.50 Degrees: The PCM has the ability to determine the amount of offset needed to bring
the engine to top dead center. This is used by the PCM to determine proper
injection timing and fuel delivery. This value may be displayed as a positive
or negative number.
MPH km/h-Range 0-98 mph: Vehicle speed is a PCM internal parameter. It is computed by timing pulses
coming from the Vehicle Speed Sensor (VSS). Vehicle speed is used in checking
TCC lock-up speed or speedometer accuracy. Speed is displayed in both
Miles Per Hour (mph) and Kilometers Per Hour (km/h).
Cruise Switch-Range ON/OFF: Indicates if the cruise switch (on turn signal lever) is in the ON position.
Cruise Active-Range ON/OFF: Indicates if vehicle is in cruise control.
Cruise Brake Sw.-Range open/closed: Is used for stop lamps and a redundant cruise control disengagement switch.
Brake Switch-Range open/closed: When the brake pedal is applied, the switch sends a signal to the PCM
to disengage the cruise control.
Set Switch-Range ON/OFF: Indicates if the cruise control set switch is activated. The scan tool
may be used to determine if the cruise control set switch is functioning properly.
Resume Switch-Range ON/OFF: Indicates if the cruise conrol resume switch is activated. The scan tool
may be used to determine if the cruise control resume set switch is functioning
properly.
TR Switch-Range Park/Neutral, Reverse, Drive 4, Drive 3, Drive
2, Low and Invalid: These values represent the decoded sequence of the transmission range
pressure switch assembly circuits and are to determine manual valve position.
Crank Ref. Missed-Range 0- 8: The scan tool will display the number of crank pulses missed. At idle
it should read 0.
Inj. Pump Cam Reference Missed-Range 0-8: The scan tool will display the number of cam pulses missed. At idle it
should read 0.
Lift Pump-Range 0-25.5 volts: The amount of voltage the lift pump system is drawing. Also, a good functional
check of the lift pump relay and oil pressure switch.
Lift Pump System-Range disabled/enabled: Indicates weather or not the PCM has requested the lift pump to be turned
ON. This display can not be used to determine if the lift pump is actually
ON.
Engine Load-Range 0-100%: The amount of load on the engine.
Engine Torque-Range 0-999 ft/lb: The amount of engine torque.
# of Curr. DTCs-Range #: Indicates the total number of current DTCs set. Does not necessarily
mean the MIL is illuminated.
DTC Set This Ign.-Range #: Indicates the total number of current DTCs set this ignition cycle.
Ignition Volts-Range 0-25.5 volts: This represents the system voltage measured by the PCM at its ignition
feed circuit. Ignition voltage is only present when vehicle is running.
TFT Sensor-Range 0-5 volts: This value represents the input signal of the transmission fluid temperature
sensor in voltage. Refer to section Refer to Transmissions.
TFT-Range- -40°C to 151°C, -40°F
to 304°F: This value represents the input signal of the transmission fluid temperature
sensor. Refer to Transmissions.
Calc. A/C Load-Range: The amount of load the A/C is putting on the engine.
A/C Compressor-Range engaged/disengaged: Indicates weather or not A/C compressor is engaged. The output test function
in the scan tool can only activated with the key ON, and the engine OFF.
A/C Request-Range ON/OFF: Represents the state of the A/C request input from the control head.
A/C Relay-Range Disabled/Enabled: Represents the commanded state of the A/C clutch control relay. The A/C
clutch should be engaged with ON displayed.
MIL Lamp-Range ON/OFF: Represents the commanded state of the Service Engine Soon (MIL) lamp.
STS Lamp-Range ON/OFF: Represents the commanded state of the Service Throttle Soon lamp.
4WDL Mode-Range: Indicates if vehicle is in the four wheel drive mode.
Front Axle Switch-Range Engaged/Disengaged: Indicates weather or not the front axle state is being detected by the
PCM.
A/B/C Range Sw.-Range On On On/Off Off Off: They are used to detect which gear has been manually selected. Engine
must be running. Refer to Transmissions.
1-2 Sol 2-3 Sol-Range On Off/On Off: These values are the command status of the 1-2 and the 2-3
shift solenoids. ON represents a commanded energized state (current flowing
through solenoid). OFF represents a commanded non-energized state (current
not flowing through solenoid). Refer to Transmissions.
TCC Enabled-Range disabled/enabled: Indicates if TCC is engaged.
PC Solenoid-On/Off: This value is the commanded state of the pressure control solenoid. Refer
to Transmissions.
Device Control-Range YES/NO: Indicates if the scan tool has taken control of a system under output
tests.
Engine Run Time-Range 00:00:00 (HRS/MIN/SEC): A measure of how long the engine has been operating. When the ignition
is cycled to OFF the value is reset to zero.
Freeze Frame and Failure Record Data Definitions: A freeze frame and failure record data list consist of a many of the
same parameters as in a Engine data list. The list below defines the parameters
not found in a Engine data list.
First Odometer-Range miles (x16): The amount of miles (in 16 mile increments) that the vehicle has traveled
since the freeze frame or failure record has been stored.
Last Odometer-Range miles (x16): Every time a failure occurs, last odometer will reset to zero. The amount
miles since the last failure (in 16 mile increments).
Fail Counter-Range (decimal): The number of ignition cycles that at test has ran and failed (at least
once).
Pass Counter-Range (decimal): The number of ignition cycles that at test has ran and passed (at least
once).
No Results Counter: The number of ignition cycles with out a result (pass or fail).