This list explains each data message displayed on the scan tool.

This information will assist you in tracking down emissions or driveability DTCs, because you can view the displays while you are driving the vehicle. Refer to Powertrain On Board Diagnostic (OBD) System Check - Automatic Transmission for additional information.

1-2 Shift Error: Range: -3.20 to +3.18 seconds. This display is the difference between the desired 1-2 shift time and the actual 1-2 shift time. The greater the negative number equals a longer shift.

1-2 Shift Time: Range: 0.00-6.38 seconds. This display is the actual time of the last 1-2 shift. The shift time is based on a gear ratio change after the commanded 1-2 shift.

1-2 Solenoid/2-3 Solenoid: Displays ON or OFF. When the transmission is in FIRST and FOURTH gear, the display should indicate ON for the 1-2 solenoid. When the transmission is in SECOND and THIRD gear, the display should indicate OFF for the 1-2 solenoid. When the transmission is in FIRST and SECOND gear, the display should indicate OFF for the 2-3 solenoid. When the transmission is in THIRD and FOURTH gear, the display should indicate ON for the 2-3 solenoid.

1-2 Solenoid Open/Short to GND: 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. This parameter is valid only when the 1-2 shift solenoid valve is commanded OFF.

1-2 Solenoid Short to Volts: Displays YES or NO. This parameter indicates if a short to voltage exists in the 1-2 shift solenoid valve feedback signal to the PCM. This parameter is valid only when the 1-2 shift solenoid valve is commanded ON.

1-2 TAP Cell (4-16): Range: -221 to +214 kPa (-32 to +31 psi). The amount of adapt pressure, based on 17 N·m (12.5 lb ft) of engine torque increment per cell, added or subtracted from shift pressure during a 1-2 upshift. A positive number indicates that the PCM has detected long shifts and has added PC solenoid pressure in order to decrease shift time. A negative number indicates that the PCM has detected short shifts and has subtracted PC solenoid pressure in order to increase shift time.

2-3 Shift Error: Range: -3.20 to +3.18 seconds. This display is the difference between the desired 2-3 shift time and the actual 2-3 shift time. The greater the negative number equals a longer shift.

2-3 Shift Time: Range: 0.00-6.38 seconds. This display is the actual time of the last 2-3 shift. The shift time is based on a gear ratio change after the commanded 2-3 shift.

2-3 Solenoid Open/Short to GND: 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. This parameter is valid only when the 2-3 shift solenoid valve is commanded OFF.

2-3 Solenoid Short to Volts: Displays YES or NO. This parameter indicates if a short to voltage exists in the 2-3 shift solenoid valve feedback signal to the PCM. This parameter is valid only when the 2-3 shift solenoid valve is commanded ON.

2-3 TAP Cell (4-16): Range: -221 to +214 kPa (-32 to +31 psi). The amount of adapt pressure, based on 17 N·m (12.5 lb ft) of engine torque increment per cell, added or subtracted from shift pressure during a 2-3 upshift. A positive number indicates that the PCM has detected long shifts and has added PC solenoid pressure in order to decrease shift time. A negative number indicates that the PCM has detected short shifts and has subtracted PC solenoid pressure in order to increase shift time.

3-4 Shift Error: Range: -3.20 to +3.18 seconds. This display is the difference between the desired 3-4 shift time and the actual 3-4 shift time. The greater the negative number equals a longer shift.

3-4 Shift Time: Range: 0.00-6.38 seconds. This display is the actual time of the last 3-4 shift. The shift time is based on a gear ratio change after the commanded 3-4 shift.

3-4 TAP Cell (4-16): Range: -221 to +214 kPa (-32 to +31 psi). The amount of adapt pressure, based on 17 N·m (12.5 lb ft) of engine torque increment per cell, added or subtracted from shift pressure during a 3-4 upshift. A positive number indicates that the PCM has detected long shifts and has added PC solenoid pressure in order to decrease shift time. A negative number indicates that the PCM has detected short shifts and has subtracted PC solenoid pressure in order to increase shift time.

A/C Clutch: Displays ON or OFF. This represents the commanded state of the A/C clutch control relay. The clutch should be engaged whenever ON is displayed. The PCM will compensate for the additional engine load that is accompanied with the A/C clutch engaged.

Cruise: Displays DISABLED or ENABLED. When the display indicates ENABLED, the PCM is allowing cruise control operation. When the display indicates DISABLED, the PCM has disabled cruise control operation. When the cruise control display is ENABLED, shift patterns will be altered for 2-3 and 3-4 upshifts or 4-3 and 3-2 downshifts.

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

Current TAP Cell: Displays Cells 4-16. This parameter indicates the current TAP cell in use for transmission line pressure adaptation. The cells are based on engine torque. The higher the engine torque, the higher the current TAP cell. The last cell used will remain displayed until the next adaptable upshift occurs.

ECT: 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 engine coolant temperature.

Engine Run Time: Displays Hours/Minutes/Seconds. This display will show how long the engine has been running. When the ignition is turned OFF, the timer is reset to zero.

Engine Speed: Range: 0-9999 RPM. Engine speed is computed by the PCM from the fuel control reference input (crankshaft position sensor). This parameter indicates the rotational speed of the engine expressed as revolutions per minute.

Engine Torque: Range: 0-510 N·m (0-406 lb ft). This display indicates the amount of torque that is delivered from the engine.

Gear Ratio:  Range: 0.00-4.00. This display is the actual transmission gear ratio as the transmission operates through all drive ranges including REVERSE and PARK/NEUTRAL. If the display indicates an unfamiliar gear ratio in PARK or NEUTRAL, this ratio will be the average ratio for all gears at the end of the drive cycle.

Ignition Voltage: Range: 0.0-25.5 V. This represents the system voltage measured by the PCM at its ignition input.

IMS: 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. If a valid combination of inputs is not received by the PCM, INVALID will be displayed. This display is the decoded status of the four A/B/C/P inputs from the automatic transmission internal mode switch. If a valid combination of inputs is not received by the PCM, INVALID will be displayed.

IMS A/B/C/P: Displays HI/LOW, HI/LOW, HI/LOW, HI/LOW. This display is the four inputs from the automatic transmission internal mode switch. HI indicates an ignition voltage signal and LOW indicates a 0 voltage signal.

Last Shift Time: Range: 0.00-6.38 seconds. This display indicates the actual shift time of the last upshift.

Lateral Accelerometer: Operating range: 0.25-4.75 V, -1.5 G. This parameter indicates the amount of lateral G's being applied to the vehicle, and is used to enable Performance Algorithm Shifting (PAS).

PC Sol. Actual Current: Range: 0.0-1.25 amps. This display is the actual current flow through the pressure control solenoid circuit which is monitored by the PCM. High current results in low line pressure. Low current results in high line pressure.

PC Solenoid Duty Cycle: Range: 0-100%. This display indicates the commanded state of the pressure control solenoid expressed as a percent of ON time (energized). No current flow indicates zero ON time or 0% duty cycle. High current flow is approximately 60% duty cycle at idle.

PC Sol. Ref. Current: Range: 0.0-1.25 amps. This display is the amount of current which the PCM has commanded through the pressure control solenoid circuit. High current results in low line pressure. Low current results in high line pressure.

Steady State TAP 1GR: Range: 0-876 kPa (0-127 psi). This display indicates a pressure modification which is added to the line pressure in 1st gear when the PCM detects a worn or slipping component.

Steady State TAP 2GR: Range: 0-876 kPa (0-127 psi). This display indicates a pressure modification which is added to the line pressure in 2nd gear when the PCM detects a worn or slipping component.

Steady State TAP 2GR w/TCC: Range: 0-876 kPa (0-127 psi). This display indicates a pressure modification which is added to the line pressure in 2nd gear with TCC applied when the PCM detects a worn or slipping component.

Steady State TAP 3GR: Range: 0-876 kPa (0-127 psi). This display indicates a pressure modification which is added to the line pressure in 3rd gear when the PCM detects a worn or slipping component.

Steady State TAP 3GR w/TCC: Range: 0-876 kPa (0-127 psi). This display indicates a pressure modification which is added to the line pressure in 3rd gear with TCC applied when the PCM detects a worn or slipping component.

Steady State TAP 4GR: Range: 0-876 kPa (0-127 psi). This display indicates a pressure modification which is added to the line pressure in 4th gear when the PCM detects a worn or slipping component.

Steady State TAP 4GR w/TCC: Range: 0-876 kPa (0-127 psi). This display indicates a pressure modification which is added to the line pressure in 4th gear with TCC applied when the PCM detects a worn or slipping component.

Steady State TAP Reverse: Range: 0-876 kPa (0-127 psi). This display indicates a pressure modification which is added to the line pressure in Reverse when the PCM detects a worn or slipping component.

TCC Brake Switch: Displays OPEN or CLOSED. This display indicates the status of the TCC brake switch circuit input to the PCM. OPEN indicates a zero voltage input (brake pedal applied). CLOSED indicates a voltage input (brake pedal released).

TCC Duty Cycle: Range: 0-100%. This display indicates the commanded percent of TCC PWM solenoid ON time. 90% represents a fully energized commanded state and 0% represents a de-energized commanded state.

TCC Duty Cycle Open/Short to GND: Displays YES or NO. This parameter indicates if an open or short to ground exists in the TCC PWM solenoid valve feedback signal to the PCM. This parameter is valid only when the TCC PWM solenoid valve is commanded OFF (duty cycle is 0%).

TCC Duty Cycle Short to Volts: Displays YES or NO. This parameter indicates if a short to voltage exists in the TCC PWM solenoid valve feedback signal to the PCM. This parameter is valid only when the TCC PWM solenoid valve is commanded ON (duty cycle is at maximum).

TCC Slip Speed: Range: -4080 to +4079 RPM. This display is the difference between the engine RPM and the RPM of the input shaft of the transmission. A negative value indicates that the engine RPM is less than the RPM of the input shaft (deceleration). A positive value indicates that the engine RPM is greater than the RPM of the input shaft (acceleration).

TFP Sw.: Displays PARK/NEUTRAL, REVERSE, DRIVE, or INVALID. This parameter is the decoded status of the two A/C inputs from the automatic transmission fluid pressure manual valve position switch. If a valid combination of inputs is not received by the PCM, INVALID will be displayed.

TFP Sw. Sig. A/Sig. C:  Displays HI/LOW. The displays are the two inputs from the automatic transmission fluid pressure manual valve position switch. LOW represents a low voltage signal (switch closed). HI represents an ignition voltage signal (switch open). The sequence of open and closed switches is used by the PCM to determine actual manual valve position.

TP Angle: Range: 0-100%. The TP angle is computed by the PCM from TP voltage. The TP angle should display 0% at idle and 100% at wide open throttle.

TP Sensor: Range: 0.0-5.0 V. The TP sensor is used by the PCM to determine the amount of throttle demanded by the driver. By monitoring the TP voltage, the PCM will modify line pressure and shift times.

Trans. Fluid. Temp.: 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 transmission fluid temperature. Transmission fluid temperature is high (151°C) when the signal voltage is low (0 V). Transmission fluid temperature is low (-40°C) when the signal voltage is high (5.1 V).

Trans. Oil Life: Displays a range of 0-100%. This parameter represents the remaining Transmission Oil Life that is calculated and maintained by the PCM.

Transmission Hot Mode: Displays ON or OFF. This display indicates transmission hot mode operation due to high transmission fluid temperature. OFF indicates that the transmission fluid temperature has not exceeded 130°C (266°F). ON indicates that the transmission fluid temperature has exceeded 130°C (266°F) and has not cooled to 120°C (248°F) for more than five seconds.

Transmission ISS: Range: 0-8191 RPM. This display indicates the rotational speed of the transmission input shaft expressed as revolutions per minute.

Transmission OSS: Range: 0-8191 RPM. This display indicates the rotational speed of the transmission output shaft expressed as revolutions per minute.

Vehicle Speed: Range: 0-255 km/h (0-158 mph). The vehicle speed sensor signal is converted by the PCM to be displayed in mph and km/h.