Transmission Control Module Scan Tool Information (6T30/6T40/6T45/6T50)

WARNING: This page is about a different car, the 2015 Chevrolet Trax and 2015 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.

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.

NOTE:

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 components.

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.

Scan Tool Data Parameters

Parameter	System State	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 Time	Varies	Seconds	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.
2-3 Shift Time	Varies	Seconds	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.
3-4 Shift Time	Varies	Seconds	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.
4-5 Shift Time	Varies	Seconds	This parameter displays the actual time of the last adaptable 4-5 shift. The actual shift time is obtained by measuring the time required for the input shaft to decelerate from the previous ratio to the current ratio.
5-6 Shift Time	Varies	Seconds	This parameter displays the actual time of the last 5-6 shift. The shift time is base on the gear ratio change after the commanded 5-6 shift.
Brake Pedal Switch	Released	Applied/Released	This parameter displays the status of the brake switch circuit input. Applied indicates a zero voltage input, brake pedal applied. Released indicates a voltage input, brake pedal released. The scan tool displays Applied or Released.
Calculated Throttle Position	Varies	%	This parameter displays a calculated value, which is determined by the accelerator pedal position and the actual throttle position, used to optimize transmission controls. It 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).
Control Module Voltage Signal	9-19	Volts	This parameter displays the system voltage measured at the module wake up signal feed.
Driver Shift Control Mode	Inactive	Active/Inactive	This parameter displays Active or Inactive. The scan tool displays Active when the gear selector is in the manual mode (M) position or left of the D position, which enables TAP shift. The scan tool displays Inactive when the gear selector is not in the M or left of D position, TAP shift disabled.
Driver Shift Request	None	Upshift / Downshift / None / Invalid	This parameter displays the current request from the TAP Shift System. This parameter will display up shift, downshift or invalid depending on the amount of voltage measured at the remote shift selector input and also will display none when there is no request.
Engine Coolant Temperature	Varies	°C (°F)	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 V). ECT is low at -40°C (-40°F) when the signal voltage is high (5 V). This parameter value is determined by the engine control module and communicated to the TCM through the High Speed GMLAN Serial Data link.
Engine Speed	Varies	RPM	This parameter displays the rotational speed of the engine expressed as revolutions per minute. This parameter value is determined by the engine control module and communicated to the TCM through the High Speed GMLAN Serial Data link.
Engine Torque	Varies	Y (lb ft)	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. This parameter value is determined by the engine control module and communicated to the TCM through the High Speed GMLAN Serial Data link.
Gear Command	1	1, 2, 3, 4, 5, or 6	This parameter displays the current commanded state of the shift solenoid valves. The scan tool displays 1, 2, 3, 4, 5, or 6.
Gear Ratio	Varies	Ratio	This parameter displays the actual transmission gear ratio. The scan tool displays the gear ratio calculated from the automatic transmission (AT) input speed sensor (ISS) and the automatic transmission (AT) output speed sensor (OSS) inputs.
High Side Driver 1	On	On/Off	This parameter displays the state of the High Side Driver 1. The scan tool displays On or Off.
High Side Driver 1 Circuit Low Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to ground exists in the high side driver 1 circuit. The scan tool displays OK, Malfunction, or Not Run.
High Side Driver 1 Circuit High Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to voltage exists in the high side driver 1 circuit. The scan tool displays OK, Malfunction, or Not Run.
High Side Driver 1 Circuit Open Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether an open exists in the high side driver 1 circuit. The scan tool displays OK, Malfunction, or Not Run.
Ignition Voltage	9-19	Volts	This parameter displays the system voltage measured at the ignition feed.
Internal Mode Switch	Park	Park-Drive 1, Open, Invalid	This parameter displays PARK, PARK/REVERSE, REVERSE, REVERSE/NEUTRAL, NEUTRAL, NEUTRAL/DRIVE 4, DRIVE 4, DRIVE 4/DRIVE 3, DRIVE 3, DRIVE 3/DRIVE 2, DRIVE 2, DRIVE 2/DRIVE 1, DRIVE 1 or INVALID. The IMS Range display represents a decoded status of the four inputs from the IMS. The combination of IMS inputs are used to determine what position the manual valve is in at any time.
Internal Mode Switch A/B/C/P	Varies	High/Low	This parameter displays the status of the four A/B/C/P inputs from the automatic transmission internal mode switch. HI indicates an ignition voltage signal and LOW indicates a 0 voltage signal. The scan tool will display High/Low, High/Low, High/Low, High/Low.
ISS/OSS Supply Voltage	OK	OK, Out of Range	This parameter displays OK, Out of Range.
Last Shift Time	Varies	Seconds	This parameter displays the actual time of the last up shift. This value is only accurate if the shift was adaptable.
Line Pressure Control Solenoid Valve Control Circuit Low Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to ground exists in the line pressure control valve 2 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Line Pressure Control Solenoid Valve Control Circuit High Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to ground exists in the line pressure control valve 2 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Line Pressure Control Solenoid Valve Performance Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a performance issue exists in the line pressure control solenoid valve control circuit by comparing the commanded current with the expected current. The scan tool displays OK, Malfunction, or Not Run.
Line Pressure Control Solenoid Valve Pressure Command	Varies	kPa (psi)	This parameter displays results in kPa (psi).
Pressure Control Solenoid Valve 2 Control Circuit Low Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to ground exists in the pressure control solenoid valve 2 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 2 Control Circuit High Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to voltage exists in the pressure control solenoid valve 2 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 2 Performance Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a performance issue exists in the pressure control solenoid valve 2 control circuit by comparing the commanded current with the expected current. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 2 Pressure Command	Varies	kPa (psi)	This parameter displays kPa (psi).
Pressure Control Solenoid Valve 3 Control Circuit Low Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to ground exists in the pressure control solenoid valve 3 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 3 Control Circuit High Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to voltage exists in the pressure control solenoid valve 3 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 3 Performance Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a performance issue exists in the pressure control solenoid valve 3 control circuit by comparing the commanded current with the expected current. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 3 Pressure Command	Varies	kPa (psi)	This parameter displays kPa (psi).
Pressure Control Solenoid Valve 4 Control Circuit Low Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to ground exists in the pressure control solenoid valve 4 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 4 Control Circuit High Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to voltage exists in the pressure control solenoid valve 4 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 4 Performance Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a performance issue exists in the pressure control solenoid valve 4 control circuit by comparing the commanded current with the expected current. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 4 Pressure Command	Varies	kPa (psi)	This parameter displays kPa (psi).
Pressure Control Solenoid Valve 5 Control Circuit Low Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to ground exists in the pressure control solenoid valve 5 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 5 Control Circuit High Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to voltage exists in the pressure control solenoid valve 5 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 5 Performance Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a performance issue exists in the pressure control solenoid valve 5 control circuit by comparing the commanded current with the expected current. The scan tool displays OK, Malfunction, or Not Run.
Pressure Control Solenoid Valve 5 Pressure Command	Varies	kPa (psi)	This parameter displays kPa (psi).
Replicated OSS CKT Status	OK	OK, Open/Short to GND, Short to Volts, Indeterminate	This parameter displays OK, Open/Short to GND, Short to Volts, Indeterminate.
Shift Solenoid Valve 1	On	On/Off	This parameter displays the commanded state of the reverse, 1st shift solenoid valve (S1). The scan tool displays On/Off.
Shift Solenoid Valve 1 Control Circuit Low Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to ground exists in the shift solenoid valve 1 control circuit. The scan tool displays OK, Malfunction, or Not Run.
1-2 Shift Solenoid Valve Control Circuit High Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to voltage exists in the shift solenoid valve 1 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Shift Solenoid Valve 1 Control Circuit Open Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether an open exists in the shift solenoid valve 1 control circuit. The scan tool displays OK, Malfunction, or Not Run.
Steady State TAP 1st Gear	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 1st Gear TCC Applied	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 2nd Gear	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 2nd Gear TCC Applied	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 3rd Gear	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 3rd Gear TCC Applied	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 4th Gear	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 4th Gear TCC Applied	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 5th Gear	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 5th Gear TCC Applied	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 6th Gear	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP 6th Gear TCC Applied	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
Steady State TAP Reverse	Varies	kPa (psi)	This parameter displays the amount of transmission adaptive pressure (TAP), which modifies the commanded clutch apply pressures.
TCC Pressure Control Solenoid Valve Control Circuit Low Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to ground exists in the TCC pressure control solenoid valve control circuit. The scan tool displays OK, Malfunction, or Not Run.
TCC Pressure Control Solenoid Valve Control Circuit High Voltage Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a short to voltage exists in the TCC pressure control solenoid valve control circuit. The scan tool displays OK, Malfunction, or Not Run.
TCC Pressure Control Solenoid Valve Performance Test Status	OK	OK, Malfunction, Not Run	This parameter displays whether a performance issue exist in the TCC pressure control solenoid valve control circuit by comparing the commanded current with the expected current. The scan tool displays OK, Malfunction, or Not Run.
TCC Pressure Control Solenoid Valve Pressure Command	Varies	kPa (psi)	This parameter displays results in kPa (psi).
TCC Slip Speed	Varies	RPM	This parameter displays the difference between transmission input speed and engine speed. A negative value indicates that the engine speed is less than the input speed, deceleration. A positive value indicates that the engine speed is greater than the input speed, acceleration. A value of zero indicates that the engine speed is equal to the input speed, TCC applied.
TCM Power-Up Temperature	Varies	°C (°F)	This displays the value of the temperature sensor inside the control solenoid and valve assembly.
TCM Temperature	Varies	°C (°F)	This displays the temperature of the TCM. This parameter displays results in °C (°F).
Transmission Fluid Pressure Switch 1	High/Low	High/Low	This parameter indicates the state of the normally closed transmission fluid pressure switch 1. Pressure to the switch is dependent on the position of the 3-5-Reverse clutch regulator valve. The scan tool displays High/Low.
Transmission Fluid Pressure Switch 3	High/Low	High/Low	This parameter indicates the state of the normally closed transmission fluid pressure switch 1. Pressure to the switch is dependent on the position of the 2-6 clutch regulator valve. The scan tool displays High/Low.
Transmission Fluid Pressure Switch 4	High/Low	High/Low	This parameter indicates the state of the normally closed transmission fluid pressure switch 1. Pressure to the switch is dependent on the position of the 1-2-3-4 clutch regulator valve. The scan tool displays High/Low.
Transmission Fluid Pressure Switch 5	High/Low	High/Low	This parameter indicates the state of the normally closed transmission fluid pressure switch 1. Pressure to the switch is dependent on the position of the R1/4-5-6 clutch regulator valve. The scan tool displays High/Low.
Transmission Fluid Life	Varies	%	This parameter displays the transmission oil life remaining. The scan tool displays the remaining oil life as a percentage. The transmission oil life is calculated based on fluid temperature and engine run time.
Transmission Fluid Temperature	Varies	°C (°F)	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 V, and transmission fluid temperature is low -40°C (-40°F ) when signal voltage is high, 5 V.
Transmission Hot Mode	On/Off	On/Off	When The transmission fluid temperature is above a temperature which varies by calibration, the TCM will alter the shift pattern until the temperature drops below a value which varies by calibration.
Transmission ISS	Varies	RPM	This parameter displays the rotational speed of the transmission input shaft. The scan tool displays input shaft speed is revolutions per minute (RPM).
Transmission OSS	Varies	RPM	This parameter displays the rotational speed of the transmission output shaft expressed as revolutions per minute.

Scan Tool Output Controls

Output Control	Description
TCC Pressure Control Solenoid Valve	The transmission control module (TCM) commands the torque converter clutch pressure control (TCC PC) solenoid pressure in order to apply and release the TCC. When the ignition is ON, and the engine is OFF, there are no limits to this control. The solenoid remains ON until commanded OFF and vice versa. When the engine is running, the following control limits apply: If the transmission range is Park, and the transmission is in hot mode, the TCC PC solenoid may not be commanded OFF. If the solenoid is requested OFF, the message "TCC OFF command disabled in Hot Mode" appears on the scan tool display. The TCC PC solenoid may not be commanded OFF for more than a calibrated amount of time. If the solenoid is commanded OFF, for a certain amount of time, the message "TCC OFF time has been exceeded" appears on the scan tool display.
Shift Solenoid: Shift Solenoid Valve 1	The TCM commands Shift Solenoid 1 ON and OFF. When the ignition is ON, and the engine is OFF, there are no limits to this control. The solenoid remains ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. When the engine is running, the following control limits apply: The transmission range must be in Park or Neutral. If the transmission range is not Park or Neutral, the message "Engine running and transmission range is not Park/Neutral" appears on the scan tool display. The solenoid remains ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. Transmission range DTCs must not be active. If a transmission range DTC is active, the message "Engine running with transmission DTC present" appears on the scan tool display.
Line Pressure Control Solenoid Valve	The scan tool is used to request pressure in increments of 207 kPa (30 psi) from 0-1862 kPa (0-270 psi). The TCM will then command the solenoid to achieve the requested pressure. When the ignition is ON, and the engine is OFF, the pressure request may be controlled within calibrated limits. There are no limits to the output control when the engine is OFF. When the engine is running, the following control limits apply: When the transmission range is Park or Neutral, the pressure request may be controlled within calibrated limits. The engine speed must be less than 1,500 RPM. If the engine speed is greater than 1,500 RPM, the message "TR in park/neutral and engine speed over 1,500 RPM" appears on the scan tool display. When the transmission range is not Park or Neutral, the requested pressure can only be controlled equal to or greater than the pressure determined by the TCM. The TCM does not allow a pressure to be selected that may cause damage to the transmission. If the requested pressure is less than allowed by the TCM, the message "Requested pressure for the Line PC Solenoid is too low" appears on the scan tool display. Transmission range DTCs must not be active. If a transmission range DTC is active, the message "Engine running with transmission DTC present" appears on the scan tool display.
Clutch PC Solenoids: Pressure Control Solenoid Valve 2 Pressure Control Solenoid Valve 3 Pressure Control Solenoid Valve 4 Pressure Control Solenoid Valve 5	The TCM commands the pressure control solenoids in order to apply and release the clutches. When the ignition is ON, and the engine is OFF, there are no limits to this control. The solenoid remains ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. When the engine is running, the following control limits apply: The transmission range must be in Park or Neutral. If the transmission range is not Park or Neutral, the message "Engine running and transmission range is not Park/Neutral" appears on the scan tool display. The solenoid remains ON until commanded OFF, and vice versa. When the output control is exited, the solenoid state is determined by the TCM. Transmission range DTCs must not be active. If a transmission range DTC is active, the message "Engine running with transmission DTC present" appears on the scan tool display.
Shift Transmission Gear	The TCM commands upshifts and downshifts. The scan tool Commanded Gear parameter should correspond with the shift solenoid combination. Refer to Shift Solenoid Valve State and Gear Ratio . When the ignition is ON, and the engine is OFF, there are no limits to this control. The scan tool shift solenoid states change to match the Commanded Gear selected. When the engine is running, the following control limits apply: The TCM does not allow a shift if it causes the engine RPM to exceed a calibrated limit. If a gear is requested and the engine speed is too high, the message "Engine speed too high" appears on the scan tool display. The TCM does not allow a 3-2 or 2-1 downshift if the vehicle speed exceeds a calibrated limit. If either downshift is requested and the vehicle speed is too high, the message "Eng. is on and veh. speed too hi for 3-2 or 2-1 downshift" appears on the scan tool display. The TCM does not allow a 4-3 downshift if the vehicle speed exceeds a calibrated limit. If a 4-3 downshift is requested and the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. The TCM does not allow an upshift if the vehicle speed exceeds a calibrated limit. If an upshift is requested and the vehicle speed is too high, the message "Vehicle speed too high" appears on the scan tool display. The TCM does not allow an upshift that is greater than the current selected transmission range (PRNDL). For example, 3rd gear is not allowed if the transmission range is D2. If an upshift is requested that is greater than the current selected transmission range, the message "Eng. running and gear request is greater than the current TR" appears on the scan tool display.
Transmission Adaptive Values Learn	The TCM commands pressure to the clutches to learn the transmission adaptive values. As the procedure is being performed, the scan tool provides operator instructions. Test may not start or may abort for the following conditions: Transmission fluid temperature must be between 70-100°C (158-212°F). Brakes and brake switch must function properly. Closed throttle and engine speed increases above 1500 RPM. Park/neutral position switch must be properly adjusted and functioning. Line pressure control is able to command 1,000 kPa (145 psi). Vehicle must be stopped. Vehicle must not be vibrating excessive.