1-2 Shift Error: This parameter displays the difference
between the desired 1-2 shift time and the actual 1-2 shift
time. A positive number indicates a firm or fast shift, the actual shift time was
shorter than the desired shift time. A negative number indicates a soft or slow shift,
the actual shift time was longer than the desired shift time. This value is only accurate
if the shift was adaptable.
1-2 Shift Time: This parameter displays the actual time
of the last adaptable 1-2 shift. The shift time is based on the gear
ratio change after the commanded 1-2 shift.
1-2 Sol.: This parameter displays the commanded state
of the 1-2 shift solenoid valve. When the transmission is in FIRST and
FOURTH gear, the display should indicate ON, current is flowing trough the solenoid.
When the transmission is in SECOND and THIRD gear, the display should indicate OFF,
current is not flowing through the solenoid.
1-2 Sol. CKT Status: This parameter displays the solenoid valve feedback voltage signal circuit status on the scan tool. If the voltage is low when the solenoid is commanded OFF, the scan tool will display Open/Short to GND. If the
voltage is high when the solenoid is commanded ON, the scan tool will display Short to Volts. If no circuit fault is present, the scan tool will display OK. Until the circuit has been evaluated, the scan tool will display Indeterminate.
1-2 Sol. Open/Short to GND: This parameter displays whether
an open or a short to ground exists in the 1-2 shift solenoid valve feedback
signal and displays Yes or No. The 1-2 shift solenoid valve must be commanded
Off for this parameter to be valid.
1-2 Sol. Short to Volts: This parameter displays if a
short to voltage exists in the 1-2 shift solenoid valve feedback signal.
This parameter is valid only when the 1-2 shift solenoid valve is commanded
ON. The scan tool will display YES or NO.
1-2 TAP Cell (4-16): This parameter displays the
amount of transmission adaptive pressure (TAP), based on 17 N·m
(12.5 lb ft) of engine torque increment per cell, added to or subtracted
from shift pressure during a 1-2 upshift. A positive number indicates
that long shifts have been detected and PC solenoid pressure has been added in order
to decrease shift time. A negative number indicates that short shifts have been detected
and PC solenoid pressure has been subtracted in order to increase shift time.
2-3 Shift Error: This parameter displays the difference
between the desired 2-3 shift time and the actual 2-3 shift
time. A positive number indicates a firm or fast shift, the actual shift time was
shorter than the desired shift time. A negative number indicates a soft or slow shift,
the actual shift time was longer than the desired shift time. This value is only accurate
if the shift was adaptable.
2-3 Shift Time: This parameter displays the actual time
of the last adaptable 2-3 shift. The shift time is based on the gear
ratio change after the commanded 2-3 shift.
2-3 Sol.: This parameter displays the commanded state
of the 2-3 shift solenoid valve. When the transmission is in FIRST and
SECOND gear, the display should indicate OFF, current is not flowing through
the solenoid. When the transmission is in THIRD and FOURTH gear, the display should
indicate ON, current is flowing through the solenoid.
2-3 Sol. CKT Status: This parameter displays the solenoid valve feedback voltage signal circuit status on the scan tool. If the voltage is low when the solenoid is commanded OFF, the scan tool will display Open/Short to GND. If the
voltage is high when the solenoid is commanded ON, the scan tool will display Short to Volts. If no circuit fault is present, the scan tool will display OK. Until the circuit has been evaluated, the scan tool will display Indeterminate.
2-3 Sol. Open/Short to GND: This parameter displays whether
an open or a short to ground exists in the 2-3 shift solenoid valve feedback
signal and displays Yes or No. The 2-3 shift solenoid valve must be commanded
Off for this parameter to be valid.
2-3 Sol. Short to Volts: This parameter displays if a
short to voltage exists in the 2-3 shift solenoid valve feedback signal.
This parameter is valid only when the 2-3 shift solenoid valve is commanded
ON. The scan tool will display YES or NO.
2-3 TAP Cell (4-16): This parameter displays the
amount of transmission adaptive pressure (TAP), based on 17 N·m
(12.5 lb ft) of engine torque increment per cell, added to or subtracted
from shift pressure during a 2-3 upshift. A positive number
indicates that long shifts have been detected and PC solenoid pressure has been added
in order to decrease shift time. A negative number indicates that short shifts have
been detected and PC solenoid pressure has been subtracted in order to increase shift
time.
3-4 Shift Error: This parameter displays the difference
between the desired 3-4 shift time and the actual 3-4 shift
time. A positive number indicates a firm or fast shift, the actual shift time was
shorter than the desired shift time. A negative number indicates a soft or slow shift,
the actual shift time was longer than the desired shift time. This value is only accurate
if the shift was adaptable.
3-4 Shift Time: This parameter displays the actual time
of the last adaptable 3-4 shift. The shift time is based on the gear
ratio change after the commanded 3-4 shift.
4WD: This parameter displays whether the vehicle is currently
in a four-wheel drive mode. The scan tool displays Enabled or Disabled.
4WD Low: This parameter displays the signal state of the four-wheel
drive low circuit. Enabled indicates a 0 voltage signal requesting 4WD low.
Disabled indicates a B+ voltage signal which does not request 4WD low. The scan tool
displays Enabled or Disabled.
A/C Clutch: This parameter displays the commanded state of the
air conditioning (A/C) compressor clutch relay driver circuit and displays
On or Off. The A/C compressor clutch should be engaged when On displays. When the
display indicates On, the line pressure and the shift times will be adjusted for the
additional engine load.
Calc. Throttle Position: This parameter displays a calculated value, which is determined by the accelerator pedal position and the actual throttle position, used to optimize transmission controls. The parameter represents the driver's intended
request for torque or acceleration. The range is 0-100%, where 0% represents an idle or coast request and 100% represents a request for wide open throttle (WOT).
Commanded Gear: This parameter displays the current commanded
state of the shift solenoid valves. The scan tool displays 1, 2, 3, 4 or 5.
Cruise: This parameter displays the commanded state of the cruise
control system. The scan tool displays ENABLED or DISABLED. When the display indicates
ENABLED, the PCM is allowing cruise control operation. When the display indicates
DISABLED, the PCM has disabled cruise control operation. When the cruise control display
is ENABLED, shift patterns will be altered for 2-3 and 3-4 upshifts or
4-3 and 3-2 downshifts.
Current TAP Cell: This parameter displays the current transmission
adaptive pressure (TAP) cell in use for transmission line pressure adaptation.
The cells are based on 17 N·m (12.5 lb ft) of engine torque.
The higher the engine torque, the higher the current TAP cell. The last cell used
will remain displayed until the next adaptable upshift occurs.
ECT: This parameter displays the input signal from the engine
coolant temperature (ECT) sensor. ECT is high at 151°C (304°F) when
the signal voltage is low, 0 volt. ECT is low at -40°C (-40°F)
when the signal voltage is high, 5 volt.
ECT: This parameter displays the input signal from the engine
coolant temperature (ECT) sensor. The scan tool displays -40 to +151°C
(-40 to +304°F). When the ECT is high at 151°C (304°F), the signal
voltage is low, 0 V. When the ECT is low at -40°C (-40°F),
the signal voltage is high, 5 V. The ECM sends the ECT information to the
transmission control module (TCM) via the high speed GMLAN serial data line.
Engine Run Time: This parameter displays a measure in Hr:Min:Sec
of the length of time the engine has been operating. When the ignition is cycled to
OFF, the value is reset to zero.
Engine Run Time: This parameter displays a measure in Hr:Min:Sec
of the length of time the engine has been operating. When the ignition is cycled
to OFF, the value is reset to zero. The ECM sends the engine run time information
to the transmission control module (TCM) via the high speed GMLAN serial data
line.
Engine Speed: This parameter displays the rotational
speed of the engine expressed as revolutions per minute.
Engine Speed: This parameter displays the engine speed, based
on a signal from the engine control module (ECM). The scan tool displays engine
speed in revolutions per minute (RPM). The ECM sends the RPM information to
the transmission control module (TCM) via the high speed GMLAN serial data
line.
Engine Torque: This parameter displays a calculated value based
on engine load, throttle position, mass air flow, and other engine inputs. This parameter
is accurate to within 20 N·m (15 ft lb) of actual measured
engine torque.
Engine Torque: This parameter displays the estimated amount
of torque that is delivered from the engine. The scan tool displays engine torque
in N·m (lb ft). The ECM sends the engine torque information to the transmission
control module (TCM) via the high speed GMLAN serial data line.
Gear Ratio: This parameter displays the actual transmission
gear ratio. The scan tool displays the gear ratio calculated from the automatic transmission
input shaft speed sensor (AT ISS) and the automatic transmission output
shaft speed sensor (AT OSS) inputs.
Ignition Voltage: This parameter displays the system voltage
measured at the ignition feed.
Last Shift Time: This parameter displays the actual time of
the last upshift. This value is only accurate if the shift was adaptable.
PC Sol. Actual Current: This parameter displays the actual current
flow through the pressure control solenoid circuit, which is measured by the control
module. High current flow results in low line pressure. Low current flow results in
high line pressure.
PC Sol. Ref. Current: This parameter displays the commanded
current of the pressure control solenoid circuit. High current results in low line
pressure. Low current results in high line pressure.
PC Sol. Duty Cycle: This parameter displays the commanded state of the pressure control solenoid, expressed as a percentage of energized ON time. A reading of low percent indicates zero ON time, non energized, or no current flow. A high
percent at idle indicates maximum ON time, energized, or high current flow.
Power Take-Off: This parameter displays when the Power
Take-Off (PTO) is engaged. PTO mode disables all transmission diagnostics.
The scan tool displays YES or NO.
Speed Ratio: This parameter displays the calculated speed ratio
of the transmission. The ratio is calculated by dividing the output speed sensor
signal by the input speed sensor signal. Gear ratio in a step-gear transmission
is calculated in the opposite manner.
TCC Brake Switch: This parameter displays the status of the
TCC brake switch circuit input. OPEN indicates a zero voltage input, brake pedal applied.
CLOSED indicates a voltage input, brake pedal released. The scan tool displays OPEN
or CLOSED.
TCC Duty Cycle: This parameter displays the commanded percentage
of ON time for the TCC PWM solenoid. A high percentage represents an ON, energized,
commanded state. 0 percent represents an OFF, non-energized, commanded
state.
TCC Duty Cycle CKT Status: This parameter displays the solenoid driver feedback voltage signal and displays the circuit status on the scan tool. If the voltage is low when the solenoid is commanded OFF, the scan tool will display Open/Short
to GND. If the voltage is high when the solenoid is commanded ON, the scan tool will display Short to Volts. If no circuit fault is present, the scan tool will display OK. Until the circuit has been evaluated, the scan tool will display Indeterminate.
TCC Duty Cycle Open/Short to GND: This parameter displays whether
an open or a short to ground exists in the TCC PWM solenoid valve feedback signal
and displays Yes or No. The TCC PWM solenoid valve must be commanded Off for this
parameter to be valid. The scan tool will display Yes only while the TCC PWM solenoid
valve is Off. The display will pulsate.
TCC Duty Cycle Short to Volts: This parameter displays whether
a short to voltage exists in the TCC PWM solenoid valve feedback signal and displays
Yes or No. The TCC PWM solenoid valve must be commanded On for this parameter to be
valid. The scan tool will display Yes only while the TCC PWM solenoid valve is On.
The display will pulsate.
TCC Slip Speed: This parameter displays the difference between
transmission input speed and engine speed. A negative value indicates the engine speed
is less than the input speed, deceleration. A positive value indicates the engine
speed is greater than the input speed, acceleration. A value of zero indicates the
engine speed is equal to the input speed, TCC applied.
TFP Sw.: This parameter displays Park/Neutral, Reverse, Drive4,
Drive3, Drive2, Drive1 or invalid. This parameter is the decoded status of the three
A/B/C inputs from the automatic transmission fluid pressure manual valve position
switch. If a valid combination of inputs is not detected, invalid will be displayed.
TFP Sw. A/B/C: This parameter displays HI/LOW, HI/LOW, HI/LOW.
This parameter indicates the status of the three inputs from the automatic transmission
fluid pressure manual valve position switch assembly. LOW represents a zero voltage
signal. HI represents an ignition voltage signal.
TFT Sensor: This parameter displays the voltage drop across
the transmission fluid temperature (TFT) sensor circuit. 5 volts is
applied to the TFT sensor circuit. The sensor is a thermistor which changes internal
resistance based on temperature. When the sensor is cold, the internal resistance
is high, resulting in a high signal voltage. As the sensor warms, the internal resistance
decreases, and the signal voltage will also decrease. A low signal voltage indicates
a warm TFT, and a high signal voltage indicates a cold TFT.
Tow/Haul Mode: This parameter displays when the transmission
is operating in a towing or hauling mode. In tow/haul mode a different shift pattern
is commanded that increases performance when towing or hauling. Shift quality and
TCC scheduling are also affected during tow/haul mode operation. The scan tool displays
Active or Inactive.
TP Angle: This parameter displays a percentage that is calculated
based on TP sensor voltage. The TP angle should display 0 percent at idle and
100 percent at wide open throttle (WOT).
TP Indicated Angle: This parameter displays the desired throttle
angle for operating conditions present at the time.
TP Sensor: This parameter displays the TP sensor voltage that
is used to determine the amount of throttle demanded by the driver. TP voltage is
used to modify line pressure and shift times.
TR Sw.: This parameter displays the decoded status of the four
A/B/C/P inputs from the transmission range switch. The scan tool displays Park, Reverse,
Neutral, Drive, Intermediate, Low, and invalid. If a valid combination of inputs is
not detected, invalid will be displayed.
TR Sw. A/B/C/P: This parameter displays the status of the four
inputs from the transmission range switch. The scan tool displays HI/LOW. HI indicates
an ignition voltage input to the control module. LOW indicates a zero voltage input
to the control module.
Traction Control: This parameter displays Active or Inactive. When the PCM/ECM receives a request for torque reduction from the electronic brake traction control module (EBTCM), Active is displayed.
Trans. Fluid Temp.: This parameter displays the input signal of the transmission fluid temperature sensor. Transmission fluid temperature is high, 151°C (304°F), when signal voltage is low, 0 volt. Transmission fluid temperature
is low, -40°C (-40°F), when signal voltage is high, 5 volt.
Trans. Slip Counter: This parameter displays the number of times
the P0894 diagnostic test has identified a slipping condition. This diagnostic test
is required, to identify a slipping condition three times in a row in order to set
the DTC P0894 Transmission Component Slipping diagnostic code. The scan tool
displays 0, 1 or 2.
Transfer Case Ratio: This parameter displays the ratio of the
transfer case, calculated by engine speed, divided by transmission output speed based
on transmission commanded gear.
Transmission Hot Mode: This parameter displays the automatic
transmission fluid temperature (TFT) and displays On or Off. Off indicates
that the TFT has not exceeded 130°C (266°F). On indicates that the TFT has
exceeded 130°C (266°F) and has not cooled to 120°C (248°F) for greater
that 5 seconds. These numbers are approximate and differ with transmissions.
Transmission ISS: This parameter displays the rotational speed
of the transmission input shaft. The scan tool displays input shaft speed as
revolutions per minute (RPM).
Transmission OSS: This parameter displays the rotational speed
of the transmission output shaft. The scan tool displays output shaft speed as revolutions
per minute (RPM). On four-wheel drive applications, the transfer case
output shaft speed is measured.
Turbine Speed: This parameter displays the rotational speed
of the torque converter turbine shaft, and is expressed as revolutions per minute (RPM).
In commanded gears 1, 2, and 3, the turbine speed equals the input speed. In commanded
gear 4, the turbine speed equals 3/4 of the input speed.
Vehicle Speed: This parameter displays the speed at which the
vehicle is traveling. The scan tool displays vehicle speed as kilometers per hour (km/h),
miles per hour (MPH). The vehicle speed is calculated based on the input signal
from the automatic transmission output shaft speed sensor.