Scan Tool Data Definitions

1-2 Sol (Solenoid) and 2-3 Sol (Solenoid): Scan tool displays ON or OFF. These parameters are the commanded states of the 1-2 and the 2-3 shift solenoid valves. ON indicates a commanded energized solenoid state, and OFF indicates a commanded non-energized solenoid state.

1-2 Sol (Solenoid) Open/Short to GND: 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 work.

1-2 Sol (Solenoid) Short to Volts: Scan tool displays YES or NO. This parameter indicates whether a short to battery (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 work.

2-3 Sol (Solenoid) Open/Short to GND: 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 work.

2-3 Sol (Solenoid) Short to Volts: Scan tool displays YES or NO. This parameter indicates whether a short to battery (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 work.

A/C Clutch: 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.

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

Cruise: 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 Enabled, shift patterns will be altered for 2-3 and 3-4 upshifts and for 4-3 and 3-2 downshifts.

Current Gear: Scan tool displays 1, 2, 3, or 4. The PCM looks at the transmission range position and the gear commanded by the PCM. The actual forward gear that the transmission is in will be the lower of the two because the manual valve overrides the PCM commanded gear.

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: Scan tool displays Hr:Min:Sec. 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 0-9,999 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 is 0 - 510 Nm (0 - 376 ft. lbs.). This parameter displays the amount of torque that is delivered from the engine.

Gear Ratio: Scan tool range 0.00-3.98. This display indicates transmission gear ratio as the transmission operates through all Drive and Reverse ranges.

Hot Mode: Scan tool displays ON or OFF. This display indicates the Automatic Transmission Fluid Temperature (TFT) status. 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.

Intake Air Temperature (IAT): Scan tool range:-40° to +215°C (-40° to +419°F). Changes in air temperature at the intake manifold cause a change in voltage across the IAT Sensor. The PCM translates the voltage into air temperature. The PCM uses IAT Sensor information to adjust the fuel delivery, the ignition timing, the line pressure and the shift timing.

Ignition Volts: Scan tool range is 0.0-25.5 volts. This parameter represents the system voltage measured by the PCM at the PCM ignition input.

Shift Mode: Scan tool displays Normal or Performance. This parameter shows the actual state of the performance control program within the PCM. On vehicles with a Second Gear start switch, the scan tool displays Performance when this switch is in the On position. When the switch is in the Off position, the scan tool displays Normal. If the vehicle is not equipped with a Second Gear start switch, this parameter will always display Normal.

Speed Ratio: Scan tool range 0-8. This parameter indicates engine RPM divided by transmission output shaft RPM.

TCC Duty Cycle: Scan tool range 0% to 100%. This display indicates the commanded percent of the TCC PWM solenoid valve on time. On the 4T60-E transmission, when the scan tool displays TCC (PWM) Duty Cycle commanded ON (and 99% Duty Cycle) the circuit is de-energized. When the scan tool displays OFF (and 0 percent Duty Cycle) the circuit is fully energized.

TCC Duty Cycle Open/Short to GND: 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 work. The Scan tool will display YES only while the TCC PWM solenoid valve is OFF. The display will pulsate.

TCC Duty Cycle Short to Volts: 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 work. The Scan tool will display YES only while the TCC PWM solenoid valve is ON. The display will pulsate.

TCC (Torque Converter Clutch) Enable: Scan tool displays YES or NO. This display indicates the commanded state of the TCC solenoid valve. YES indicates an energized solenoid and NO indicates a non-energized solenoid. The commanded states of YES and NO occur under various vehicle speeds and various PCM inputs.

TCC (Torque Converter Clutch) Enable Open/Short to GND: Scan tool 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. The TCC solenoid valve must be commanded OFF for this parameter to work.

TCC (Torque Converter Clutch) Enable Short to Volts: Scan tool displays YES or NO. This parameter indicates whether a short to battery (B+) exists in the TCC solenoid valve feedback signal to the PCM. The TCC solenoid valve must be commanded ON for this parameter to work.

TCC (Torque Converter Clutch) Slip Speed: Scan tool range-4080 to +4079 RPM. This display is the engine RPM less the transmission output shaft RPM. A negative value indicates deceleration: the engine I RPM is less than the output shaft RPM. A positive value indicates acceleration: the engine RPM is more than the output shaft RPM. A value of zero indicates that TCC is applied: the engine RPM is equal to the output shaft RPM.

Trans. Fluid Temp.: Scan tool range-40°C to 140°C (-40°F to 284°F). This display is the temperature conversion of the TFT voltage input signal to the PCM. When the TFT is high (140°C, 284°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, and the PCM monitors a high signal voltage. The PCM interprets this voltage as a cold transmission. As the sensor warms, the internal resistance decreases, and the voltage signal decreases. 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 percent at Wide Open Throttle (WOT).

Traction Control: Scan tool displays Active or Inactive. This display will show Active when the PCM receives a signal from the Electronic Brake Traction Control Module (EBTCM) requesting torque reduction during a traction control maneuver. If the vehicle is not equipped with Traction Control, then this parameter will always display Inactive.

Transmission OSS (Output Speed Sensor): Scan tool range 0-8,191 RPM. This display indicates the rotational speed of the transmission output shaft expressed in revolutions per minute.

Vehicle Speed (km/h, mph): Scan tool range 0-255 km/h (0-158 mph). This parameter is the Vehicle Speed Sensor (VSS) input signal converted by the PCM.