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

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 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 typical 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 adaptable 5-6 shift. The shift time is based on the gear ratio change after the commanded 5-6 shift.

Brake 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.

Calc. Throttle Position

Varies

%

This parameter displays a calculated value, which is determined by the accelerator pedal position and the actual throttle position, used to optimise transmission controls. It represents the driver's intended request for torque or acceleration. The range is 0-100%, where 0% represents an idle or freewheel request and 100% represents a request for wide open throttle (WOT).

Commanded Gear

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.

Driver Shift Control

Inactive

Active/Inactive

This parameter displays Active or Inactive. The scan tool displays Active when the gear selector is in the sport (S) position, which enables TAP shift. The scan tool displays Inactive when the gear selector is not in the S 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.

ECT

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).

Engine Speed

Varies

RPM

This parameter displays the rotational speed of the engine expressed as revolutions per minute.

Engine torque

Varies

N·m (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.

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/Off

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 Status

OK

OK, Open/Short to GND, Short to Volts, Indeterminate

This parameter displays whether an open, short to voltage or ground exists in the driver 1 circuit. The scan tool displays OK, Open/Short to Volts, Short to GND.

Ignition Voltage

9-19

Volts

This parameter displays the system voltage measured at the ignition feed.

IMS

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.

IMS A/B/C/P

Varies

HI/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 HI/LOW, HI/LOW, HI/LOW, HI/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 upshift. This value is only accurate if the shift was adaptable.

Line PC Sol. CKT Status

OK

OK, Open/Short to GND, Short to Volts, Indeterminate

This parameter displays whether an open, short to voltage or ground exists in the line pressure control (PC) solenoid valve feedback signal circuit. The scan tool displays OK, Open/Short to Volts, Short to GND.

Line PC Sol. Pressure Command

Varies

kPa (psi)

This parameter displays results in kPa (psi).

PC Sol. 2 CKT Status

OK

OK, Open/Short to GND, Short to Volts, Indeterminate

This parameter displays OK, Open/Short to GND, Short to Volts.

PC Sol. 2 Pressure Command

Varies

kPa (psi)

This parameter displays kPa (psi).

PC Sol. 3 CKT Status

OK

OK, Open/Short to GND, Short to Volts, Indeterminate

This parameter displays OK, Open/Short to GND, Short to Volts.

PC Sol. 3 Pressure Command

Varies

kPa (psi)

This parameter displays kPa (psi).

PC Sol. 4 CKT Status

OK

OK, Open/Short to GND, Short to Volts, Indeterminate

This parameter displays OK, Open/Short to GND, Short to Volts.

PC Sol. 4 Pressure Command

Varies

kPa (psi)

This parameter displays kPa (psi).

PC Sol. 5 CKT Status

OK

OK, Open/Short to GND, Short to Volts, Indeterminate

This parameter displays OK, Open/Short to GND, Short to Volts.

PC Sol. 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 Sol. 1 CKT Status

OK

OK, Open/Short to GND, Short to Volts, Indeterminate

This parameter displays OK, Open/Short to GND, Short to Volts, or Indeterminate.

Shift Solenoid 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 Sol. 2 CKT Status

OK

OK, Open/Short to GND, Short to Volts, Indeterminate

This parameter displays OK, Open/Short to GND, Short to Volts, or Indeterminate.

Shift Solenoid 2

On

On/Off

This parameter displays the commanded state of the 2-3, 3-4 shift solenoid valve (S2). The scan tool displays On/Off.

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 PC Sol. 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 Temperature

Varies

°C (°F)

This parameter displays results in °C (°F).

TFP Switch 1

HI/LOW

HI/LOW

This parameter displays the state of the first clutch oil pressure switch. The scan tool displays HI/LOW.

TFP Switch 3

HI/LOW

HI/LOW

This parameter displays state of the 3rd clutch oil pressure switch. The scan tool displays HI/LOW.

TFP Switch 4

HI/LOW

HI/LOW

This parameter displays state of the 4th clutch oil pressure switch. The scan tool displays HI/LOW.

TFP Switch 5

HI/LOW

HI/LOW

This parameter displays state of the fifth clutch oil pressure switch. The scan tool displays HI/LOW.

Trans. 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.

Trans. Fluid Temp.

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 in 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 Control Solenoid
    • 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 1
    • Shift Solenoid 2
    • The TCM commands Shift Solenoid 1 and Shift Solenoid 2 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 PC Solenoid
    • 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:

    • PC Solenoid 2
    • PC Solenoid 3
    • PC Solenoid 4
    • PC Solenoid 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
    • 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.

Service Cleaning Procedure

Control limits are not defined at this time.

   


© Copyright Chevrolet. All rights reserved
   


© Copyright Chevrolet. All rights reserved