Transmission Scan Tool Data Definitions

1-2 Shift Error: Scan tool range: -3.20 to +3.18 seconds. This parameter is the difference between the desired 1-2 shift time and the actual 1-2 shift time. A negative number equals a longer shift time.

1-2 Shift Time: Scan tool range: 0.00 - 6.38 seconds. This parameter is the actual shift time of the last 1-2 shift. The shift time is based on a gear box ratio change after the commanded 1-2 shift.

1-2 Sol. (Solenoid): The scan tool displays On or Off. This parameter is the commanded state of the 1-2 shift solenoid valve. On indicates a commanded energized solenoid state, and Off indicates a commanded non-energized solenoid state.

1-2 Sol. (Solenoid) Open/Short to Ground: The scan tool displays Yes or No. This parameter indicates whether an open or a short to ground exists in the 1-2 shift solenoid valve feedback signal to the PCM. The 1-2 shift solenoid valve must be commanded Off for this parameter to be valid.

1-2 Sol. (Solenoid) Short to Volts: The scan tool displays Yes or No. This parameter indicates whether a short to bakery (B+) exists in the 1-2 shift solenoid valve feedback signal to the PCM. The 1-2 shift solenoid valve must be commanded On for this parameter to be valid.

1-2 TAP Cell (4-16): Scan tool range: -207 to +207 kPa (-30 to +30 psi). The amount of adapt pressure, based on 17 Nm (12.5 ft. lbs.) of engine torque increment per cell, added to or subtracted from shift pressure during a 1-2 upshift. A large positive number means the PCM has seen several long shifts and has added PC solenoid pressure in order to decrease the shift time. A large negative number means the PCM has seen several short shins and has removed PC solenoid pressure in order to increase the shift time.

2-3 Shift Error: Scan tool range: -3.20 to +3.18 seconds. This parameter is the difference between the desired 2-3 shift time and the actual 2-3 shift time. A negative number equals a longer shift time.

2-3 Shift Time: Scan tool range: 0.00 - 6.38 seconds. This parameter is the actual shift time of the last 2-3 shift. The shift time is based on a gear box ratio change after the commanded 2-3 shift.

2-3 Sol. (Solenoid): The scan tool displays On or Off. This parameter is the commanded state of the 2-3 shift solenoid valve. On indicates a commanded energized state, and Off indicates a commanded non-energized state.

2-3 Sol. (Solenoid) Open/Short to Ground: The scan tool displays Yes or No. This parameter indicates whether an open or a short to ground exists in the 2-3 shift solenoid valve feedback signal to the PCM. The 2-3 shift solenoid valve must be commanded Off for this parameter to be valid.

2-3 Sol. (Solenoid) Short to Volts: The scan tool displays Yes or No. This parameter indicates whether a short to bakery (B+) exists in the 2-3 shift solenoid valve feedback signal to the PCM. The 2-3 shift solenoid valve must be commanded On for this parameter to be valid.

2-3 TAP Cell (4-16):Scan tool range: -207 to +207 kPa (-30 to +30 psi). The amount of adapt pressure, based on 17 Nm (12.5 ft. lbs.) of engine torque increment per cell, added to or subtracted from shift pressure during a 2-3 upshift. A large positive number means the PCM has seen several long shifts and has added PC solenoid pressure in order to decrease the shift time. A large negative number means the PCM has seen several short shifts and has removed PC solenoid pressure in order to increase the shift time.

3-4 Shift Error: Scan tool range: -3.20 to +3.18 seconds. This parameter is the difference between the desired 3-4 shift time and the actual 3-4 shift time. A negative number equals a longer shift time.

3-4 Shift Time:Scan tool range: 0.00 - 6.38 seconds. This parameter is the actual shift time of the last 3-4 shift. The shift time is based on a gear box ratio change after the commanded 3-4 shift.

3-4 TAP Cell (4-16): Scan tool range: -207 to +207 kPa (-30 to +30 psi). The amount of adapt pressure, based on 17 Nm (12.5 ft. lbs.) of engine torque increment per cell, added to or subtracted from shift pressure during a 3-4 upshift. A large positive number means the PCM has seen several long shifts and has added PC solenoid pressure in order to decrease the shift time. A large negative number means the PCM has seen several short shifts and has removed PC solenoid pressure in order to increase the shift time.

A/C Clutch:The scan tool displays On or Off. This represents the PCM commanded state of the A/C compressor clutch relay driver circuit. 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.

Adaptable Shift: The scan tool displays Yes or No. When the transmission's adapt capability is functional, the scan tool displays Yes during the shift calculation and until the commanded gear changes. When the transmission's adapt capability is not functional, the scan tool displays No.

Brake Switch: Scan tool range: Open/Closed. When the brake pedal is applied, the TCC brake switch sends a signal to the PCM to disengage the TCC and disable cruise control.

Cruise: 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. The PCM has the ability to disable cruise control under certain conditions. When the cruise control is On, shift patterns will be altered for 2-3 and 3-4 upshifts for 4-3 and 3-2 downshifts.

Current Gear: The scan tool displays 1, 2, 3 or 4. This parameter indicates the current commanded state of the shift solenoid valves.

Current TAP (Transmission Adaptive Pressure) Cell: Scan tool range: 0-16. This parameter indicates the current TAP cell used for line pressure modification (adapt).

Current TAP (Transmission Adaptive Pressure) Memory: Scan tool range: -110 to +110 kPa (-16 to +16 psi). This parameter is the amount of pressure which must be added to base line pressure in order to adjust the apply effort of a clutch or a band during a shift.

ECT (Engine Coolant Temperature): Scan tool range: -40°C to 151°C (-40°F to 304°F). The ECT sensor is mounted in the coolant stream and sends engine temperature information to the PCM. The PCM applies 5 volts to the ECT sensor circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold (the internal resistance is high), the PCM monitors a high signal voltage. The PCM interprets this voltage as a cold engine. As the sensor warms (the internal resistance decreases), the voltage signal will decrease. The PCM interprets the lower voltage as a warm engine.

Engine Run Time: The scan tool displays hours/minutes/seconds. This parameter indicates the time elapsed since the engine was started. If the engine is stopped, this parameter is reset to 00:00:00.

Engine Speed (RPM): Scan tool range: 0 - 8192 RPM. The engine speed is computed by the PCM from the fuel control reference input (the crankshaft position sensor). This parameter indicates the rotational speed of the engine expressed as revolutions per minute.

Engine Torque: Scan tool range: 0 - 510 Nm (0 - 376.1 ft. lbs.). This parameter is the torque delivered by the engine.

Gear Ratio: Scan tool range: 0.00 - 3.98. This display is the actual transmission gear ratio as the transmission operates through all DRIVE, REVERSE and PARK/NEUTRAL ranges.

Hot Mode: The scan tool displays On or Off. This display indicates the automatic transmission Fluid temperature (TFT). 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. Note: these numbers are approximate. They differ with transmissions.

Ignition Voltage: Scan tool range: 0.0 - 25.5 V. This parameter is the system voltage measured by the PCM at the PCM ignition input when the ignition switch is in the RUN position.

Last Shift Time: Scan tool range: 0.00 - 6.38 seconds. This parameter is the actual shift time of the last upshift.

PC Sol. (Pressure Control Solenoid Valve) Actual Current: Scan tool range: 0.0 - 1.25 amps. This parameter is the actual current flow through the PC solenoid valve circuit, as measured by the PCM. Low current flow indicates high line pressure. High current flow indicates low line pressure.

PC Sol. (Pressure Control Solenoid Valve) Duty Cycle: Scan tool range: 0 - 100%. This parameter indicates the commanded state of the PC solenoid valve circuit, expressed as a percentage of ON time (energized). 0% duty cycle indicates no current flow (zero ON time). High current flow is approximately 60% duty cycle at idle.

PC Sol. (Pressure Control Solenoid Valve) Reference Current: Scan tool range: 0.0 - 1.25 amps. This parameter is the current flow commanded by the PCM through the PC solenoid valve circuit. Low current flow indicates high firm pressure. High current flow indicates low line pressure.

Shift Mode: The scan tool displays Normal or Performance. This parameter indicates the state of the performance control program. The scan tool displays Normal when the performance mode is not active. The scan tool displays Performance when the performance mode is active on vehicles equipped with a shift select switch.

Steady State TAP 1 GR: Scan tool range: 0 to 621 kPa (0 to +90 psi). The amount of adapt pressure that is applied to PC solenoid pressure to maintain the first gear ratio (eliminate clutch or band slip). A large number means the PCM has seen an element slipping and is compensating with adapt pressure.

Steady State TAP 2GR: Scan tool range: 0 to 621 kPa (0 to +90 psi). The amount of adapt pressure that is applied to PC solenoid pressure to maintain the second gear ratio (eliminate clutch or band slip). A large number means the PCM has seen an element slipping and is compensating with adapt pressure.

Steady State TAP 2GR/TC: Scan tool range: 0 to 621 kPa (0 to +90 psi). The amount of adapt pressure that is applied to PC solenoid pressure to maintain the second gear ratio with TCC applied (eliminate clutch or band slip). A large number means the PCM has seen an element slipping and is compensating with adapt pressure.

Steady State TAP 3GR: Scan tool range: 0 to 621 kPa (0 to +90 psi). The amount of adapt pressure that is applied to PC solenoid pressure to maintain the third gear ratio (eliminate clutch or band slip). A large number means the PCM has seen an element slipping and is compensating with adapt pressure.

Steady State TAP 3GR/TC: Scan tool range: 0 to 621 kPa (0 to +90 psi). The amount of adapt pressure that is applied to PC solenoid pressure to maintain the third gear ratio with TCC applied (eliminate clutch or band slip). A large number means the PCM has seen an element slipping and is compensating with adapt pressure.

Steady State TAP 4GR: Scan tool range: 0 to 621 kPa (0 to +90 psi). The amount of adapt pressure that is applied to PC solenoid pressure to maintain the fourth gear ratio (eliminate clutch or band slip). A large number means the PCM has seen an element slipping and is compensating with adapt pressure.

Steady State TAP 4GRITC: Scan tool range: 0 to 621 kPa (0 to +90 psi). The amount of adapt pressure that is applied to PC solenoid pressure to maintain the fourth gear ratio with TCC applied (eliminate clutch or band slip). A large number means the PCM has seen an element slipping and is compensating with adapt pressure.

Steady State TAP Refers (Reverse): Scan tool range: 0 to 621 kPa (0 to +90 psi). The amount of adapt pressure that is applied to PC solenoid pressure to maintain the reverse gear ratio (eliminate clutch or band slip). A large number means the PCM has seen an element slipping and is compensating with adapt pressure.

TCC (Torque Converter Clutch) Duty Cycle: Scan tool range: 0 - 100 percent. This display indicates the commanded percent of the TCC PWM solenoid valve On time. A value of 20 percent represents an energized commanded state and a value of 0 percent represents a de-energized commanded state. The commanded state is applied at vehicle speeds that are above approximately 16 km/h (10 mph).

TCC (Torque Converter Clutch) Duty Cycle Open/ Short to GND: The scan tool 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. 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 (Torque Converter Clutch) Duty Cycle Short to Volts: The scan tool displays Yes or No. This parameter indicates whether a short to battery (B+) exists in the TCC PWM solenoid valve feedback signal to the PCM. 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 (Torque Converter Clutch) Release Pressure: The scan tool displays Yes or No. This parameter is the status of the normally-closed TCC release switch. A scan tool displaying Yes indicates the switch is open, TCC release Fluid pressure is present and the TCC is released. A scan tool displaying No indicates the switch is closed, TCC release Fluid pressure is not present and the TCC is applied.

TCC (Torque Converter Clutch) Slip Speed: Scan tool range: -4080 to +4079 RPM. This display is the difference between the transmission input shaft RPM and the engine RPM. A negative value indicates deceleration. A value of near zero indicates that the TCC is applied.

TFP (Automatic Transmission Fluid Pressure) Range: The scan tool displays Park, Reverse, Neutral, Drive 4, Drive 3, Drive 2 or Drive 1. TFP Range display represents a decoded status of the three inputs to the PCM from the TFP manual valve position switch. The combination of TFP manual valve position switch inputs indicates the position of the manual valve using Fluid pressure switch states.

TFP (Automatic Transmission Fluid Pressure Manual Valve Position) Sw. A/B/C: The scan tool displays On or Off. The parameters are the three inputs for Range A/B/C from the automatic Transmission Fluid Pressure (TFP) manual valve position switch. On represents a low voltage signal, indicating that the switch is closed. Off represents a high voltage signal, indicating that the switch is open. The PCM uses the input sequence in order to determine the actual manual valve position. The PCM uses the actual manual valve position in order to control the line pressure, the TCC and the shift solenoid valves.

Trans. Fluid Temp. (Automatic Transmission Fluid Temperature): Scan tool range: -40 to +151°C (-40 to +304°F). This display is the temperature conversion of the voltage input signal to the PCM of the TFT. When the TFT is high (151°C, 304°F), the signal voltage is low (0.00 volts). When the TFT is low (-40°C, -40°F), the signal voltage is high (5.00 volts).

TFT (Automatic Transmission Fluid Temperature) Sensor: Scan tool range: 0.00 - 5.00 volts. This display shows the voltage drop across the TFT sensor. The PCM applies 5 volts to the TFT sensor circuit. The sensor is a thermistor which changes internal resistance as the temperature changes. When the sensor is cold (the internal resistance is high), the PCM monitors a high signal voltage. The PCM interprets this voltage as a cold transmission. As the sensor warms (the internal resistance decreases), the voltage signal will decrease. The PCM interprets the lower voltage as a warm transmission.

TP (Throttle Position) Sensor:Scan tool range: 0.00 - 5.00 volts. This parameter indicates the voltage being monitored by the PCM on the TP sensor signal circuit.

TP (Throttle Position) Angle: Scan tool range: 0 - 100%. The TP angle is computed by the PCM from the TP sensor voltage. The TP angle should display 0% at idle and 100% at wide open throttle (WOT).

Traction Control: The scan tool displays Active or Inactive. The scan tool displays Active when the PCM receives a request for torque reduction from the electronic brake traction control module (EBTCM).

Transmission ISS (Input Shaft Speed): Scan tool range: 0 - 8191 RPM. This parameter is the rotational speed of the transmission input shaft.

Transmission OSS (Output Shaft Speed): Scan tool range: 0 - 8191 RPM. This display indicates the rotational speed of the transmission output shaft as expressed in revolutions per minute.

Vehicle Speed: Scan tool range: 0-255 km/h (0 - 158 mph). This parameter is the vehicle speed sensor (VSS) input signal converted by the PCM to be displayed as vehicle speed in both metric and English units.