K71 Transmission Control Module: Scan Tool Information
The Transmission Control Module Scan Tool Data List contains all transmission related parameters that are available on the scan tool. 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.
Only the parameters listed below are used/referenced in this service information 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 value described below, refer to Symptoms - Automatic Transmission . If A DTC is set refer to Diagnostic Trouble Code (DTC) List - Vehicle .
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 with the upper radiator hose hot and in closed loop operation, closed throttle, transmission in park, accessories OFF, brake pedal not applied. | |||
| 5V Reference 1 | Varies | Volts | Indicates the voltage on the reference circuit. |
| 5V Reference 2 | Varies | Volts | Indicates the voltage on the reference circuit. |
| 9V Reference 1 Circuit Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| 9V Reference 2 Circuit Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Calculated Line Pressure | Varies | kPa/PSI | Indicates a calculated line pressure value based on various engine and transmission input data. |
| Calculated Throttle Position | Varies | % | Indicates a calculated value based on accelerator pedal position and throttle position. Zero percent indicates idle position and 100 percent indicates wide open throttle. |
| Control Module Voltage Signal | Varies | Voltage | Indicates the voltage value on the signal circuit to the Transmission Control Module. |
| Current Gear | Varies | 1 - 10, Varies from transmission model | Indicates the current gear range the transmission has obtained. |
| Driver Shift Control | Varies | Active/Inactive | Indicates the driver has taken control of shifting the transmission. |
| Driver Shift Control Mode | Varies | Inactive/Upshift/Downshift | Indicates to the transmission control module the driver has taken control of transmission shifting by placing the gear shift lever in manual mode. Transmission control module will allow manual shifting within limits. |
| Engine Coolant Temperature | Varies | °C (°F) | Indicates to the transmission control module the temperature of the engine coolant temperature, sent from the engine control module. |
| Engine Speed | Varies | RPM | Indicates the rotational speed of the engine crankshaft in revolutions per minute. |
| Engine Torque | Varies | N.m | Indicates a calculated value based on various engine input and output data values. |
| Gear Command | Varies | 1 - 10, Varies from transmission model | Indicates the current gear range the transmission control module has commanded. |
| Gear Ratio | Varies | 9 Speed FWD Transmission 1st = 4.689 2nd = 3.306 3rd = 3.012 4th = 2.446 5th = 1.923 6th = 1.446 7th = 1.000 8th = 0.747 9th = 0.617 Rev. = -2.960 |
Indicates a calculated value based on the RPM values of the ISS, Intermediate SS and OSS. |
| High Side Driver 1 or 2 Circuit High Voltage Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| High Side Driver 1 or 2 Circuit Low Voltage Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| High Side Driver 1 or 2 Circuit Open Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| High Side Driver 1 or 2 | Varies | ON/OFF | Indicates the commanded state of the transmission control module high side drivers. |
| Ignition 1 Signal | ON | ON/OFF | Indicates the transmission control module has received the ignition 1 signal. |
| Ignition Accessory Signal | ON | ON/OFF | Indicates the transmission control module has received the ignition accessory voltage signal. |
| Ignition Voltage | Varies | Volts | Indicates the available ignition voltage to the transmission control module. |
| Power Mode | Varies | OFF/Accessory/Run/Crank Request | Indicates to the transmission control module the present position of the ignition switch. |
| TCC Slip Speed | Varies | RPM | Indicates the RPM difference between the torque converter impeller and the torque converter turbine when the converter clutch is applied. |
| Transmission Accumulator Solenoid Valve | Varies | ON/OFF | Indicates if the transmission control module has commanded a transmission control solenoid either ON or OFF. |
| Transmission Accumulator Solenoid Valve Control Circuit High Voltage Test Status | OK | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Accumulator Solenoid Valve Control Circuit Low Voltage Test Status | OK | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Accumulator Solenoid Valve Control Circuit Open Test Status | OK | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Control Solenoid Valve 1 - 8 Calibration Data | Valid | Valid/Invalid/Not Programmed | Indicates if the calibration data for the programmable solenoid is programmed or programmed correctly. |
| Transmission Control Solenoid Valve 1 - 8 Calibration Data | Valid | Valid/Invalid/Not Programmed | Indicates if the solenoids are programmed with the correct calibration data. |
| Transmission Control Solenoid Valve 1 - 8 Current Command | Varies | Amperage | Indicates the commanded amperage flowing through the solenoid at any given time. |
| Transmission Control Solenoid Valve 1 - 9 | Varies | OFF/ON | Indicates if the transmission control module has commanded a transmission control solenoid either ON or OFF. |
| Transmission Control Solenoid Valve 1 - 10 Control Circuit High Voltage Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Control Solenoid Valve 1 - 10 Control Circuit Low Voltage Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Control Solenoid Valve 1 - 10 Control Circuit Open Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Fluid Temperature | Varies | °C (°F) | Indicates the temperature of the transmission fluid in the transmission oil pan. |
| Transmission Hot Mode | NO | No/Yes | Indicates if the transmission control module has commanded hot mode operation. |
| Transmission Input Speed Sensor | Varies | RPM | Indicates the rotational speed of the transmission input shaft in revolutions per minute. |
| Transmission Intermediate Speed Sensor | Varies | RPM | Indicates the rotational speed of the transmission 3-8 and 5-7-R clutch hub assembly. |
| Transmission Output Speed Sensor | Varies | RPM | Indicates the rotational speed of the transmission output shaft in revolutions per minute. |
| Transmission Range Sensor 1 | Varies | % | Indicates the percentage of duty cycle of the PWM signal from the transmission range switch to the transmission control module. |
| Transmission Range Sensor 2 | Varies | % | Indicates the percentage of duty cycle of the PWM signal from the transmission range switch to the engine control module. |
| Up and Downshift Switch | Varies | Invalid/Upshift/Downshift/None | Indicates to the transmission control module the driver has requested an upshift or downshift from the Up or Down shift switch, on the shift lever. |
| Up and Downshift Switch 1 | Varies | Invalid/Upshift/Downshift/None | Indicates to the transmission control module the driver has requested an upshift or downshift from the Up or Down shift switch, on the shift lever. |
| Up and Downshift Switch 2 | Varies | Inactive/Upshift/Downshift/None | Indicates to the transmission control module the driver has requested an upshift or downshift from the second additional set of switches, if equipped. |
| Upshift/Downshift | Varies | Inactive/Upshift/Downshift | Indicates to the transmission control module the driver has requested an upshift or downshift. |
| Vehicle Speed | Varies | km/h (MPH) | Indicates the rotational speed of the drive wheels in km/h (MPH). |
Scan Tool Output Control Functions
| Parameter | System State | Expected Value | Description |
|---|---|---|---|
| High Side Driver 1 Command | Varies | ON/OFF | Allows you to command the high side driver 1 ON or OFF. |
| High Side Driver 2 Command | Varies | ON/OFF | Allows you to command the high side driver 2 ON or OFF. |
| Shift Transmission Gear | Varies | 1 - 10 | Allows you to upshift the transmission from 1st gear to 8th gear and downshift from 8th to 1st gear. Be aware the transmission control module has limits to the gear selection, protect the engine and transmission. |
| Transmission Accumulator Pressure Charging | Varies | ON/OFF | Allows you to charge the accumulator with line pressure with the engine running. |
| Transmission Accumulator Solenoid Valve | Varies | OFF/ON | Allows you to command solenoid OFF or ON. |
| Transmission Service Fast Learn | - | - | A service fast learn procedure to be perform for any internal component repair/replacement, solenoid/valve body replacement, complete transmission replacement or transmission control module replacement. |
| Transmission Control Solenoid Valve 1 - 10 | Varies | OFF/ON | Allows you to command solenoid valve 1 - 10 OFF or ON. |
| Transmission Control Solenoid Valve 1 - 10 Current | Varies | 0 - 1.2 Amps | Allow you to command the transmission solenoids 1 - 10 electrical current from 0 - 1.2 amps. |
The Transmission Control Module Scan Tool Data List contains all transmission related parameters that are available on the scan tool. 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.
Only the parameters listed below are used/referenced in this service information 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 value described below, refer to Symptoms - Automatic Transmission . If A DTC is set refer to Diagnostic Trouble Code (DTC) List - Vehicle .
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 with the upper radiator hose hot and in closed loop operation, closed throttle, transmission in park, accessories OFF, brake pedal not applied. | |||
| 5V Reference 1 | Varies | Volts | Indicates the voltage on the reference circuit. |
| 5V Reference 2 | Varies | Volts | Indicates the voltage on the reference circuit. |
| 9V Reference 1 Circuit Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| 9V Reference 2 Circuit Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Calculated Line Pressure | Varies | kPa/PSI | Indicates a calculated line pressure value based on various engine and transmission input data. |
| Calculated Throttle Position | Varies | % | Indicates a calculated value based on accelerator pedal position and throttle position. Zero percent indicates idle position and 100 percent indicates wide open throttle. |
| Control Module Voltage Signal | Varies | Voltage | Indicates the voltage value on the signal circuit to the Transmission Control Module. |
| Current Gear | Varies | 1 - 10, Varies from transmission model | Indicates the current gear range the transmission has obtained. |
| Driver Shift Control | Varies | Active/Inactive | Indicates the driver has taken control of shifting the transmission. |
| Driver Shift Control Mode | Varies | Inactive/Upshift/Downshift | Indicates to the transmission control module the driver has taken control of transmission shifting by placing the gear shift lever in manual mode. Transmission control module will allow manual shifting within limits. |
| Engine Coolant Temperature | Varies | °C (°F) | Indicates to the transmission control module the temperature of the engine coolant temperature, sent from the engine control module. |
| Engine Speed | Varies | RPM | Indicates the rotational speed of the engine crankshaft in revolutions per minute. |
| Engine Torque | Varies | N.m | Indicates a calculated value based on various engine input and output data values. |
| Gear Command | Varies | 1 - 10, Varies from transmission model | Indicates the current gear range the transmission control module has commanded. |
| Gear Ratio | Varies | 9 Speed FWD Transmission 1st = 4.689 2nd = 3.306 3rd = 3.012 4th = 2.446 5th = 1.923 6th = 1.446 7th = 1.000 8th = 0.747 9th = 0.617 Rev. = -2.960 |
Indicates a calculated value based on the RPM values of the ISS, Intermediate SS and OSS. |
| High Side Driver 1 or 2 Circuit High Voltage Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| High Side Driver 1 or 2 Circuit Low Voltage Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| High Side Driver 1 or 2 Circuit Open Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| High Side Driver 1 or 2 | Varies | ON/OFF | Indicates the commanded state of the transmission control module high side drivers. |
| Ignition 1 Signal | ON | ON/OFF | Indicates the transmission control module has received the ignition 1 signal. |
| Ignition Accessory Signal | ON | ON/OFF | Indicates the transmission control module has received the ignition accessory voltage signal. |
| Ignition Voltage | Varies | Volts | Indicates the available ignition voltage to the transmission control module. |
| Power Mode | Varies | OFF/Accessory/Run/Crank Request | Indicates to the transmission control module the present position of the ignition switch. |
| TCC Slip Speed | Varies | RPM | Indicates the RPM difference between the torque converter impeller and the torque converter turbine when the converter clutch is applied. |
| Transmission Accumulator Solenoid Valve | Varies | ON/OFF | Indicates if the transmission control module has commanded a transmission control solenoid either ON or OFF. |
| Transmission Accumulator Solenoid Valve Control Circuit High Voltage Test Status | OK | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Accumulator Solenoid Valve Control Circuit Low Voltage Test Status | OK | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Accumulator Solenoid Valve Control Circuit Open Test Status | OK | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Control Solenoid Valve 1 - 8 Calibration Data | Valid | Valid/Invalid/Not Programmed | Indicates if the calibration data for the programmable solenoid is programmed or programmed correctly. |
| Transmission Control Solenoid Valve 1 - 8 Calibration Data | Valid | Valid/Invalid/Not Programmed | Indicates if the solenoids are programmed with the correct calibration data. |
| Transmission Control Solenoid Valve 1 - 8 Current Command | Varies | Amperage | Indicates the commanded amperage flowing through the solenoid at any given time. |
| Transmission Control Solenoid Valve 1 - 9 | Varies | OFF/ON | Indicates if the transmission control module has commanded a transmission control solenoid either ON or OFF. |
| Transmission Control Solenoid Valve 1 - 10 Control Circuit High Voltage Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Control Solenoid Valve 1 - 10 Control Circuit Low Voltage Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Control Solenoid Valve 1 - 10 Control Circuit Open Test Status | Varies | Not Run/OK/Malfunction | Indicates if the transmission control module has run a diagnostic circuit test and/or displays the present electrical condition of the circuit. |
| Transmission Fluid Temperature | Varies | °C (°F) | Indicates the temperature of the transmission fluid in the transmission oil pan. |
| Transmission Hot Mode | NO | No/Yes | Indicates if the transmission control module has commanded hot mode operation. |
| Transmission Input Speed Sensor | Varies | RPM | Indicates the rotational speed of the transmission input shaft in revolutions per minute. |
| Transmission Intermediate Speed Sensor | Varies | RPM | Indicates the rotational speed of the transmission 3-8 and 5-7-R clutch hub assembly. |
| Transmission Output Speed Sensor | Varies | RPM | Indicates the rotational speed of the transmission output shaft in revolutions per minute. |
| Transmission Range Sensor 1 | Varies | % | Indicates the percentage of duty cycle of the PWM signal from the transmission range switch to the transmission control module. |
| Transmission Range Sensor 2 | Varies | % | Indicates the percentage of duty cycle of the PWM signal from the transmission range switch to the engine control module. |
| Up and Downshift Switch | Varies | Invalid/Upshift/Downshift/None | Indicates to the transmission control module the driver has requested an upshift or downshift from the Up or Down shift switch, on the shift lever. |
| Up and Downshift Switch 1 | Varies | Invalid/Upshift/Downshift/None | Indicates to the transmission control module the driver has requested an upshift or downshift from the Up or Down shift switch, on the shift lever. |
| Up and Downshift Switch 2 | Varies | Inactive/Upshift/Downshift/None | Indicates to the transmission control module the driver has requested an upshift or downshift from the second additional set of switches, if equipped. |
| Upshift/Downshift | Varies | Inactive/Upshift/Downshift | Indicates to the transmission control module the driver has requested an upshift or downshift. |
| Vehicle Speed | Varies | km/h (MPH) | Indicates the rotational speed of the drive wheels in km/h (MPH). |
Scan Tool Output Control Functions
| Parameter | System State | Expected Value | Description |
|---|---|---|---|
| High Side Driver 1 Command | Varies | ON/OFF | Allows you to command the high side driver 1 ON or OFF. |
| High Side Driver 2 Command | Varies | ON/OFF | Allows you to command the high side driver 2 ON or OFF. |
| Shift Transmission Gear | Varies | 1 - 10 | Allows you to upshift the transmission from 1st gear to 8th gear and downshift from 8th to 1st gear. Be aware the transmission control module has limits to the gear selection, protect the engine and transmission. |
| Transmission Accumulator Pressure Charging | Varies | ON/OFF | Allows you to charge the accumulator with line pressure with the engine running. |
| Transmission Accumulator Solenoid Valve | Varies | OFF/ON | Allows you to command solenoid OFF or ON. |
| Transmission Service Fast Learn | - | - | A service fast learn procedure to be perform for any internal component repair/replacement, solenoid/valve body replacement, complete transmission replacement or transmission control module replacement. |
| Transmission Control Solenoid Valve 1 - 10 | Varies | OFF/ON | Allows you to command solenoid valve 1 - 10 OFF or ON. |
| Transmission Control Solenoid Valve 1 - 10 Current | Varies | 0 - 1.2 Amps | Allow you to command the transmission solenoids 1 - 10 electrical current from 0 - 1.2 amps. |