Transmission Scan Tool Data Definitions

1-2 Shift Error: Displays a range of -6.38 to +6.38 seconds. This parameter is the difference between the desired 1-2 shift time and the actual 1-2 shift time. This value is only accurate if the Adaptable Shift parameter indicates Yes.

1-2 Shift Time: Displays a range of 0.00-6.38 seconds. This parameter is the actual time of the last 1-2 shift. The shift time is based on the engine RPM drop after the commanded 1-2 shift. This value is only accurate if the Adaptable Shift parameter indicates Yes.

1-2 Sol.: Displays ON or OFF. This parameter is the commanded state of the 1-2 shift solenoid valve. ON represents a commanded energized state (current is flowing through the solenoid). OFF represents a non-commanded state (current is not flowing through the solenoid).

1-2 Sol. Open: Displays Yes or No. This parameter indicates if an open or short to ground exists in the 1-2 shift solenoid valve feedback signal to the PCM/VCM. Yes can only be displayed when the solenoid is commanded OFF.

1-2 Sol. Shorted: Displays Yes or No. This parameter indicates if a short to B+ exists in the 1-2 shift solenoid valve feedback signal to the PCM/VCM. Yes can only be displayed when the solenoid is commanded ON.

2-3 Shift Error: Displays a range of -6.38 to +6.38 seconds. This parameter is the difference between the desired 2-3 shift time and the actual 2-3 shift time. This value is only accurate if the Adaptable Shift parameter indicates Yes.

2-3 Shift Time: Displays a range of 0.00-6.38 seconds. This parameter is 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. This value is only accurate if the Adaptable Shift parameter indicates Yes.

2-3 Sol.: Displays ON or OFF. This parameter is the commanded state of the 2-3 shift solenoid valve. ON represents a commanded energized state (current is flowing through the solenoid). OFF represents a non-commanded state (current is not flowing through the solenoid).

2-3 Sol. Open: Displays Yes or No. This parameter indicates if an open or short to ground exists in the 2-3 shift solenoid valve feedback signal to the PCM/VCM. Yes can only be displayed when the solenoid is commanded OFF.

2-3 Sol. Shorted: Displays Yes or No. This parameter indicates if a short to B+ exists in the 2-3 shift solenoid valve feedback signal to the PCM/VCM. Yes can only be displayed when the solenoid is commanded ON.

3-2 Downshift Sol.: Displays On or Off. This parameter indicates 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 30 mph with a throttle increase.

3-2 Downshift Sol. Open: Displays Yes or No. This parameter indicates if an open or short to ground exists in the 3-2 shift solenoid valve assembly feedback signal to the PCM/VCM. Yes can only be displayed when a 3-2 downshift is being commanded.

3-2 Downshift Sol. Shorted: Displays Yes or No. This parameter indicates if a short to B+ exists in the 3-2 shift solenoid valve assembly feedback signal to the PCM/VCM. Yes can only be displayed when a 3-2 downshift is not being commanded.

3-4 Shift Error:  Displays a range of -6.38 to +6.38 seconds. This parameter is the difference between the desired 3-4 shift time and the actual 3-4 shift time. This value is only accurate if the Adaptable Shift parameter indicates Yes.

3-4 Shift Time: Displays a range of 0.00-6.38 seconds. This parameter is 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 Adaptable Shift parameter indicates Yes.

4WD: Displays Enabled or Disabled. This parameter indicates whether the vehicle is currently in a four-wheel drive mode.

4WD Low: Displays Enabled or Disabled. This parameter is the signal state of the four-wheel drive low circuit. Enabled indicates a 0 voltage signal (4WD Low requested). Disabled indicates a B+ voltage signal (4WD Low not requested).

A/C Clutch: Displays On or Off. This parameter indicates the commanded state of the A/C control relay. The clutch should be engaged when On displays.

Adaptable Shift (2.2L PCM): Displays a range of 0-4. When an upshift is initiated, a number of contingencies are checked to determine if the actual shift time is valid to compare to a desired shift time. If all of these contingencies are met during the entire shift, then the shift is considered valid and the adapt function may be utilized. There are also, however, separate modifiers to the adapt function that are used to provide a greater adaptive system response for a particular shift condition. The normal adaptive validation contingencies do not apply for these modifiers. The numbers displayed in this parameter indicate if the last shift met the normal validation contingencies to enable the adapt function or if the last shift required a special adaptive modifier. Zero (0) indicates that the last shift did not meet the normal validation contingencies to enable the adapt function. One (1) indicates that a run-through shift condition was detected during the last shift and the subsequent adaptive modification took place. A run-through shift signifies a very short shift time. Two (2) indicates that a long shift delay was detected during the last shift and the adaptive modification occurred. A shift delay is determined from the time that the PCM commands the shift until the start of the engine RPM drop. Three (3) indicates that an extra long shift time was detected during the last shift and the adaptive modification occurred. The shift time is calculated from the beginning of the engine RPM drop to the beginning of the engine RPM increase. Four (4) indicates that the last shift did not meet the normal validation contingencies to enable the adapt function. Shift times are only accurate when 4 is displayed.

Adaptable Shift (4.3L VCM): Displays Yes or No. Yes indicates that the proper operating conditions were all within the proper operating range during the last shift and that the shift time was accurate. This shift information is then used through the adaptive function in order to update the adapt cells. No indicates that not all of the operating conditions were met in order to enable this function and that the adapt cells were not updated. Proper operating conditions include TP Sensor Delta, Engine Torque, Vehicle Speed Delta, Engine Vacuum and Shift Delay.

Cruise: Displays Enabled or Disabled. This parameter indicates whether the PCM/VCM is allowing cruise operation. The PCM/VCM has the ability to disable cruise control under certain conditions.

Current Gear: Displays 1, 2, 3 or 4. This parameter indicates the current commanded state of the shift solenoids.

Current TAP (Transmission Adaptive Pressure): Displays a TP cell range of 0-16. This parameter indicates the current throttle position cell used for line pressure modification (adaptation).

ECT (Engine Coolant Temperature): Displays a range of -40°C to 151°C (-40°F to 304°F). This parameter is the input signal of the engine coolant temperature sensor. The engine coolant temperature is high (151°C) when the signal voltage is low (0 V), and the engine coolant temperature is low (-40°) when the signal voltage is high (5 V).

Engine Run Time: Displays a range of 0:00:00-18:12:15 hr/min/sec. This parameter measures how long the engine has been operating. When the ignition switch is turned OFF, the value is reset to zero.

Engine Speed: Displays a range of 0-8192 RPM. This parameter indicates the rotational speed of the engine expressed as revolutions per minute.

Engine Torque: Displays a range of 0-9999 ft. lbs. This parameter indicates the amount of torque that is delivered from the engine.

IAT (Intake Air Temperature 2.2L PCM): Displays a range of -40°C to 215°C (-40°F to 419°F). The IAT sensor is a thermistor located in the fresh air duct to the throttle body and is used to monitor the temperature of the air entering the throttle body. The PCM applies 5 volts to the sensor on a 5-volt reference circuit. When the air is cool, the resistance in the sensor will be high. If the air is warm, the sensor resistance will be low and the PCM will sense a low voltage signal. The PCM converts the signal of the IAT sensor to degrees Celsius. Intake air temperature is used by the PCM to adjust fuel delivery and spark timing.

Ignition Voltage: Displays a range of 0.0-25.5 V. This represents the system voltage measured by the PCM/VCM at it's ignition feed.

Last TAP: Displays psi. This parameter indicates the amount of pressure that was added to base line pressure to adjust the apply effort of a clutch or band during the last adapting shift.

Maximum TAP (Transmission Adaptive Pressure): Displays Yes or No. This parameter indicates when line pressure modification (adaptation) has reached its limit. Yes indicates that the limit has been reached. No indicates that the limit has not been reached.

PC Sol. Actual Current: Displays a range of 0.00-1.10 amps. This parameter is the actual current of the pressure control solenoid circuit at the control module. Zero amp (no current flow) indicates actual higher line pressure. Actual lower line pressure is indicated by 1.1 amps (high current flow).

PC Sol. Duty Cycle: Displays a range of 0-100%. This parameter is the commanded state of the pressure control solenoid expressed as a percent of energized ON time. Zero percent indicates zero ON time (non-energized) or no current flow. Approximately 60% at idle indicates maximum ON time (energized) or high current flow.

PC Ref. (Reference) Current: Displays a range of 0.00-1.10 amps. This parameter is the commanded current of the pressure control solenoid circuit. Zero amp (no current flow) indicates commanded higher line pressure. Commanded lower line pressure is indicated by 1.1 amps (high current flow).

Power Take Off: Displays Yes or No. This parameter indicates when Power Take Off (PTO) is engaged. PTO mode will disable all transmission diagnostics.

Speed Ratio: Displays a range of 0.00:1-8.00:1. This parameter indicates engine speed divided by transmission output speed. This value is used to estimate transmission gear ratio.

TAP % of TP: Displays psi. This parameter indicates the amount of pressure, based on a specific throttle position, that is added to base line pressure to adjust the apply effort of a clutch or band during a shift.

TCC Brake Switch: Displays Open or Closed. This parameter indicates the state of the brake switch circuit input. Open indicates a zero voltage input (brake switch open, brake pedal applied). Closed indicates a B+ voltage input (brake switch closed, brake pedal released).

TCC Duty Cycle: Displays a range of 0-100%. This parameter is the commanded percentage of ON time of the TCC PWM solenoid. Approximately 90% represents an ON (energized) commanded state. Zero percent represents an OFF (non-energized) commanded state. This commanded state is applied at a vehicle speed between approximately 0-16 km/h (0-10 mph).

TCC Duty Cycle Open: Displays Yes or No. This parameter indicates whether an open or a short to ground exists in the TCC PWM solenoid valve feedback signal to the PCM/VCM. Yes can only be displayed when the solenoid is commanded OFF (duty cycle is 0%).

TCC Duty Cycle Shorted: Displays Yes or No. This parameter indicates whether a short to B+ exists in the TCC PWM solenoid valve feedback signal to the PCM/VCM. Yes can only be displayed when the solenoid is commanded ON (duty cycle is at maximum).

TCC Enable: Displays Yes or No. This parameter is 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.

TCC Enable Open: Displays Yes or No. This parameter indicates whether an open or a short to ground exists in the TCC solenoid valve feedback signal to the PCM/VCM. Yes can only be displayed when the solenoid is commanded OFF.

TCC Enable Shorted: Displays Yes or No. This parameter indicates whether a short to B+ exists in the TCC solenoid valve feedback signal to the PCM/VCM. Yes can only be displayed when the solenoid is commanded ON.

TCC (Torque Converter Clutch) Slip Speed: Displays a range of -4080 to 4079 RPM. This parameter is 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).

TFT (Transmission Fluid Temperature) Sensor: Displays a range of 0.00-5.00 V. When the transmission fluid is cold, the sensor resistance is high and the PCM/VCM will sense high signal voltage. As the transmission fluid temperature warms to a normal operating temperature, the sensor resistance becomes less and the voltage decreases.

TFP Switch A/B/C: Displays On/Off, On/Off, On/Off. These parameters are the three inputs from the Automatic Transmission Fluid Pressure Manual Valve Position Switch Assembly. On represents a 0 voltage signal. Off represents a B+ voltage signal.

TP (Throttle Position) Angle: Displays a range of 0-100%. The TP angle is computed by the PCM/VCM from the TP sensor voltage. The TP angle should read 0% at idle and 100% at Wide Open Throttle (WOT).

TP (Throttle Position) Sensor: Displays a range of 0.00-5.00 V. The TP sensor is used by the PCM/VCM to determine the amount of throttle demanded by the driver. Voltage is below 1 volt at idle and above 4 volts at Wide Open Throttle (WOT).

Trans. Fluid Temp.: Displays a range of -40°C to 151°C (-40°F to 304°F). This parameter is the input signal of the transmission fluid temperature sensor. Transmission fluid temperature is high (151°C) when signal voltage is low (0 V), and transmission fluid temperature is low (-40°) when signal voltage is high (5 V).

Transmission Hot Mode: Displays On or Off. This parameter monitors transmission temperature. On indicates that the transmission temperature has exceeded 135°C (275°F).

Transmission OSS (Output Speed Sensor): Displays a range of 0-8192 RPM. This parameter indicates the rotational speed of the transmission output shaft expressed as revolutions per minute.

Vehicle Speed: Displays a range of 0-255 km/h (0-158 mph). This parameter is the input signal from the vehicle speed sensor assembly.