Transmission Control Module Scan Tool Information 4L60-E
| Table 1: | Scan Tool Data Parameters |
| Table 2: | Scan Tool Output Controls |
The Transmission Control Module Scan Tool Data List contains all transmission related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.
The values below represent a typical display recorded from a properly functioning system.
Important: Do not use a scan tool that displays faulty data. Report the condition to the scan tool manufacturer. The use of a faulty scan tool can result in misdiagnosis and the unnecessary replacement of parts.
Only the parameters listed below are used/referenced in this manual for diagnosis. If a scan tool displays other parameters, those values are not recommended by General Motors for use in diagnosis.
If all values are within the expected range described below, refer to Symptoms - Automatic Transmission for diagnosis.
The scan tool values from a properly functioning transmission may be used for comparison with the transmission you are diagnosing. The values below represent a typical display recorded from a properly functioning system.
Parameter | Expected Value | Description |
|---|---|---|
Operating Conditions: Engine at idle, upper radiator hose hot, closed throttle, transmission in Park, closed loop operation, accessories OFF, brake pedal not applied. | ||
1-2 Shift Error | Seconds, Varies | 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 | Seconds, Varies | This parameter displays the actual time of the last 1-2 shift. The shift time is based on the RPM drop after the commanded 1-2 shift. This value is only accurate if the shift was adaptable. |
1-2 Sol. | On | 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 through 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. Open/Short to GND | No | 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 | No | 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) | kPa (psi), Varies | 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 | Seconds, Varies | 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 | Seconds, Varies | This parameter displays the actual time of the last 2-3 shift. The shift time is based on the engine RPM drop after the commanded 2-3 shift. The value is only accurate if the shift was adaptable. |
2-3 Sol. | On | 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 ON, current is not flowing through the solenoid. When the transmission is in THIRD and FOURTH gear, the display should indicate OFF, current is flowing through the solenoid. |
2-3 Sol. Open/Short to GND | No | 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 | No | 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) | kPa (psi), Varies | 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. |
3-2 Downshift Sol. | On | This parameter displays if the 3-2 shift solenoid valve assembly is currently commanded On or Off. The solenoid commanded state is based on the transmission temperature. The solenoid will change states during a 3-2 downshift to regulate the appropriate pressure. The commanded state of the solenoid occurs at approximately 48 km/h (30 mph) with a throttle increase. The scan tool displays On or Off. |
3-2 Sol. Open/Short to GND | No | This parameter displays whether an open or a short to ground exists in the 3-2 shift solenoid valve feedback signal and displays Yes or No. The 3-2 shift solenoid valve must be commanded Off for this parameter to be valid. |
3-2 Sol. Short to Volts | No | This parameter displays if a short to voltage exists in the 3-2 shift solenoid valve feedback signal. This parameter is valid only when the 3-2 shift solenoid valve is commanded ON. The scan tool will display YES or NO. |
3-4 Shift Error | Seconds, Varies | 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 | Seconds, Varies | This parameter displays the actual time of the last 3-4 shift. The shift time is based on the engine RPM drop after the commanded 3-4 shift. This value is only accurate if the shift was adaptable. |
4WD | Disabled | This parameter displays whether the vehicle is currently in a four-wheel drive mode. Displays Enabled or Disabled |
4WD Low | Disabled | 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 | Off | 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. |
Commanded Gear | 1 | This parameter displays the current commanded state of the shift solenoid valves. The scan tool displays 1,2,3,4 or 5. |
Cruise | Disabled | 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 | Varies | 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 up shift occurs. |
ECT | °C (°F), Varies | 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. |
Engine Run Time | Hr/Min/Sec, Varies | This parameter displays a measure in Hr:Min:Sec the length of time the engine has been operating. When the ignition is cycled to OFF, the value is reset to zero. |
Engine Speed | RPM, Varies | This parameter displays the rotational speed of the engine expressed as revolutions per minute. |
Engine Torque | N·m, Varies | 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 lb ft) of actual measured engine torque. |
Estimated Gear Ratio | Ratio, Varies | This parameter displays the estimated turbine speed divided by the transmission output speed. Estimated turbine speed is calculated from engine speed and engine torque. |
Ignition Voltage | Volts, 12-14 | This parameter displays the system voltage measured at the ignition feed. |
Last Shift Time | Seconds, Varies | This parameter displays the actual time of the last up shift. This value is only accurate if the shift was adaptable. |
PC Sol. Actual Current | Amps, Varies | 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. Duty Cycle | %, Varies | 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. |
PC Sol. Ref. Current | Amps, Varies | 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. |
Power Take Off | On | 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 | Ratio, Varies | This parameter displays the calculated speed ratio of the transmission. The ratio is calculate 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 | Closed | 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 display OPEN or CLOSED. |
TCC Duty Cycle | %, Varies | 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 Open/Short to GND | No | 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 | No | 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 Enable | No | This parameter displays the commanded state of the TCC solenoid. Yes indicates a commanded energized state, current is flowing through the solenoid. No indicates a commanded non-energized state, current is not flowing through the solenoid. This commanded state occurs at various vehicle speeds between applications. The scan tool displays Yes or No. |
TCC Enable Open/Short to GND | No | This parameter displays whether an open or a short to ground exists in the TCC solenoid valve feedback signal. This parameter is valid only when the TCC solenoid is commanded Off. The scan tool displays Yes or No. |
TCC Enable Short to Volts | No | This parameter displays whether a short to voltage exists in the TCC solenoid valve feedback signal. This parameter is valid only when the TCC solenoid is commanded On. The scan tool displays Yes or No. |
TCC Slip Speed | RPM, Varies | This parameter displays the difference between transmission output speed and engine speed. A negative value indicates that the engine speed is less than the output speed, deceleration. A positive value indicates that the engine speed is greater than the output speed, acceleration. A value of zero indicates that the engine speed is equal to the output speed, TCC applied. |
TFP Sw. | Park/Neutral | 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 | HI/LOW/HI | 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 | Varies | This parameter displays the voltage drop across the transmission fluid temperature (TFT) sensor circuit. Five 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, the signal voltage will also decrease. A low signal voltage indicates a warm TFT, and a high signal voltage indicates a cold TFT. |
Torque Converter Efficiency | Ratio, Varies | This parameter displays a ratio of 0.00:1 to 2:1. The ratio is calculated by multiplying the speed ratio by a value related to the "K factor" of the torque converter. The "K factor" is the looseness or tightness of the torque converter for a given torque. The nearer the torque converter is to full coupling, i.e. 1:1, the closer the torque converter efficiency number will be to 1. |
Tow/Haul Mode | Inactive | 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 (Vehicles w/o Traction Control) | %, Varies | 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 (Vehicles with Traction Control) | %, Varies | This parameter displays the desired throttle angle for operating conditions present at the time. |
TP Sensor (Vehicles w/o Traction Control) | Volts, 0.3-0.9 | 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. | Park | 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 | LOW/HI/HI/LOW | 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 | Inactive | This parameter displays Active or Inactive. When the PCM receives a request for torque reduction from the electronic brake traction control module (EBTCM), Active is displayed. |
Trans. Fluid Temp. | °C (°F), Varies | 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, and transmission fluid temperature is low -40°C (-40°F ) when signal voltage is high, 5 volt. |
Trans. Slip Counter | 0 | 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 | Ratio, Varies | 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 | Off | 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 more that 5 seconds. These numbers are approximate. They differ with transmissions. |
Transmission OSS | RPM, Varies | This parameter displays the rotational speed of the transmission output shaft expressed as revolutions per minute (RPM). On four-wheel drive applications, the transfer case output shaft speed is measured. |
Vehicle Speed | km/h (mph), Varies | 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 vehicle speed sensor. |
Output Control | Description | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1-2 Solenoid |
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2-3 Solenoid |
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3-2 Downshift Solenoid |
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Clear TAP (Transmission Adaptive Pressures) |
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PC Solenoid |
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Preset Transmission Adapts |
Important: Depending on the application, this procedure may set some or all Transmission Adaptive values to zero. This procedure will clear the current Transmission Shift Adaptives to preset engineered values. | ||||||||||||||||||
Shift Transmission |
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TCC Control Solenoid |
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TCC Enable |
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Transmission Control Module Scan Tool Information 4L80-E
| Table 1: | Scan Tool Data Parameters |
| Table 2: | Scan Tool Output Controls |
The Transmission Control Module Scan Tool Data List contains all transmission related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.
The values below represent a typical display recorded from a properly functioning system.
Important: Do not use a scan tool that displays faulty data. Report the condition to the scan tool manufacturer. The use of a faulty scan tool can result in misdiagnosis and the unnecessary replacement of parts.
Only the parameters listed below are used/referenced in this manual for diagnosis. If a scan tool displays other parameters, those values are not recommended by General Motors for use in diagnosis.
If all values are within the expected range described below, refer to Symptoms - Automatic Transmission for diagnosis.
The scan tool values from a properly functioning transmission may be used for comparison with the transmission you are diagnosing. The values below represent a typical display recorded from a properly functioning system.
Parameter | Expected Value | Description |
|---|---|---|
Operating Conditions: Engine at idle, upper radiator hose hot, closed throttle, transmission in PARK, closed loop operation, accessories OFF, brake pedal not applied. | ||
1-2 Shift Error 4.8L and 6.0L | Seconds, Varies | 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 | Seconds, Varies | 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. | On | 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 6.6L | No | 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 4.8L and 6.0L | No | 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 4.8L and 6.0L | No | 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) | kPa/psi, Varies | 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 4.8L and 6.0L | Seconds, Varies | 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 | Seconds, Varies | 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. | Off | 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 6.6L | No | 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 4.8L and 6.0L | No | 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 4.8L and 6.0L | No | 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) | kPa/psi, Varies | 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 | Seconds, Varies | 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 | Seconds, Varies | 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 | Disabled | This parameter displays whether the vehicle is currently in a four-wheel drive mode. The scan tool displays Enabled or Disabled. |
4WD Low | Disabled | 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 4.8L and 6.0L | Off | 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 6.6L | % | 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 | 1 | This parameter displays the current commanded state of the shift solenoid valves. The scan tool displays 1, 2, 3, 4 or 5. |
Cruise 4.8L and 6.0L | Disabled | This parameter displays the commanded state of the cruise control system. The scan tool displays ENABLED or DISABLED. When the display indicates ENABLED, the powertrain control module (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 | 0-16, Varies | 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 4.8L and 6.0L | °C (°F), Varies | 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 6.6L | °C (°F), Varies | 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 4.8L and 6.0L | Hr:Min:Sec, Varies | 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 6.6L | Hr:Min:Sec, Varies | 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 4.8L and 6.0L | RPM, 600-800 | This parameter displays the rotational speed of the engine expressed as revolutions per minute (RPM). |
Engine Speed 6.6L | RPM, 600-800 | 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 4.8L and 6.0L | N·m, 10 | 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 6.6L | N·m, 10 | 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 | Ratio, 3.98:1 | 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 | Volts, 13.5-14.5 | This parameter displays the system voltage measured at the ignition feed. |
Last Shift Time | Seconds, Varies | This parameter displays the actual time of the last upshift. This value is only accurate if the shift was adaptable. |
PC Sol. Actual Current | Amps, 0.92 | 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. Duty Cycle | Percent On Time, Varies | 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. |
PC Sol. Ref. Current | Amps, 0.92 | 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. |
Power Take-Off | Off | This parameter displays when the power take-off (PTO) is engaged. PTO mode disables all transmission diagnostics. The scan tool displays On or Off. |
Speed Ratio | Ratio, 8.00:1 | 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 | CLOSED | 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 | Percent, 0% | This parameter displays the commanded percentage of ON time for the torque converter clutch pulse width modulation (TCC PWM) solenoid. A high percentage represents an ON, energized, commanded state. 0% represents an OFF, non-energized, commanded state. |
TCC Duty Cycle CKT Status 6.6L | NO | 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 4.8L and 6.0L | No | 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 4.8L and 6.0L | No | 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 | RPM, +/- 150 | 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. | Park/Neutral | 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 | HI/LOW/HI | 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 4.8L and 6.0L | Volts, Varies | 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 4.8L and 6.0L | Inactive | 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 Vehicles w/o Traction Control 4.8L and 6.0L | Percent, 0% | 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 Vehicles with Traction Control 4.8L and 6.0L | Percent, 0-10% | This parameter displays the desired throttle angle for operating conditions present at the time. |
TP Sensor Vehicles w/o Traction Control 4.8L and 6.0L | Volts, 0.3-0.9 V | 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. |
Traction Control 4.8L and 6.0L | Inactive | 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. |
TR Sw. | Park | 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 | LOW/HI/HI/LOW | 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. |
Transfer Case Ratio | Ratio, 3.22:1 | This parameter displays the ratio of the transfer case, calculated by engine speed, divided by transmission output speed based on transmission commanded gear. |
Trans. Fluid Temp. | °C (°F), Varies | 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 | 0 | 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. |
Transmission Hot Mode | Off | 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 | RPM, 600-800 | This parameter displays the rotational speed of the transmission input shaft. The scan tool displays input shaft speed as RPM. |
Transmission OSS | RPM, 0 | This parameter displays the rotational speed of the transmission output shaft. The scan tool displays output shaft speed as RPM. On four-wheel drive applications, the transfer case output shaft speed is measured. |
Turbine Speed | RPM, 600-800 | This parameter displays the rotational speed of the torque converter turbine shaft, and is expressed as 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 | km/h (mph), 0 | 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. |
Output Control | Description | ||||||||||||||||||
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1-2 Solenoid |
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2-3 Solenoid |
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Clear TAP (Transmission Adaptive Pressures) |
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PC Solenoid |
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Shift Transmission |
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TCC Control Solenoid |
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