The following define 3T40 transmission data message displayed on the scan tool.

A/C Clutch: Displays ON or OFF. This indicates whether the HVAC selector is requesting the Air Conditioning (A/C). The input is received by the Instrument Panel Cluster (IPC) and then the signal is sent over UART serial data to the PCM, and finally the signal is sent to the scan tool over class 2 serial data.

BARO: Range 11-105 kPa, 0-5.0V. The Barometric Pressure (BARO) sensor measures the change in the intake manifold pressure which results from altitude changes. This value is updated when the ignition is turned to the run position and also at Wide Open Throttle (WOT).

Brake Switch: Displays Open or Closed. This parameter indicates the state of the TCC brake switch circuit input. 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: Displays Disabled or Enabled. This signal indicates whether the cruise control system is in control of vehicle speed. The signal is sent to the PCM from the cruise control module.

Desired Idle Speed: Range 0-3,187 RPM. PCM commands the idle speed. The PCM will compensate for various engine loads in order to keep the engine at the desired idle speed.

ECT: Range -40°C to 151°C (-40°F to 304°F). The Engine Coolant Temperature (ECT) sensor sends engine temperature information to the PCM. The PCM supplies five volts to the engine coolant temperature sensor circuit. The sensor is a thermistor which changes internal resistance as the temperature changes. When the sensor is cold, meaning the internal resistance is high, the PCM monitors a high voltage which the PCM interprets as a cold engine. As the sensor warms, meaning the internal resistance decreases, the voltage signal decreases. The PCM interprets the low voltage as a warm engine.

Engine Run Time: Range 0:00:00-18:12:15 (hours:minutes:seconds). The engine run time is a measure of how long the engine has been running. When the engine stops running, the timer is reset to zero.

Engine Speed: Range 0-16,384 RPM. Engine speed is computed by the PCM, from the fuel control reference input. Engine speed should remain close to desired idle under various engine loads.

Engine Torque: Displays a range of 0-510 N·m (0-376 lb ft). This parameter displays the amount of torque that is delivered from the engine.

Ignition Voltage: Range 0-25.5V. This represents the system voltage measured by the PCM at the ignition feed circuit.

MAP: Range 11-105 kPa, 0-5.0V. The Manifold Absolute Pressure (MAP) sensor measures the change in the intake manifold pressure which results from engine load and speed changes. As the intake manifold pressure increases, the air density in the intake also increases and additional fuel is required.

Number of DTCs: Range 0-255. This indicates the total number of current Diagnostic Trouble Codes (DTCs) which have been set.

Speed Ratio: Displays a range of 0-255. This parameter indicates engine speed divided by vehicle speed.

TCC Enable: Displays Yes or No. This parameter is the commanded PCM state of the TCC solenoid valve. Yes indicates a commanded energized state. No indicates a commanded non-energized state. This commanded state occurs at various vehicle speeds.

TCC Slip Speed: Range -6,375 to +6,375 RPM. The Torque Converter Clutch (TCC) Slip Speed shows the amount of slippage in RPM between the engine and the transmission output shaft. Slip speed RPM is only accurate when the transmission is in 3rd gear, with the Torque Converter Clutch applied.

TP Angle: Range 0-100%. From the TP sensor voltage input, the PCM computes the Throttle Position. The TP angle will auto zero to 0% at idle (TP voltage below 0.90 volt). The TP angle will read 100% at Wide Open Throttle.

TP Sensor: Range 0-5.0V. The PCM uses the Throttle Position (TP) sensor in order to determine the amount of the throttle demanded by the vehicle's operator. The TP sensor reads between 0.36-0.96 volt at idle to above 4 volts at Wide Open Throttle (WOT).

Transmission OSS: Range 0-8,192 RPM. The Vehicle Speed Sensor (VSS) Assembly indicates the rotational speed of the transmission output shaft expressed as revolutions per minute.

Transmission Range: Displays Park/Reverse/Neutral/Drive/Drive 2/Low/Invalid. The scan tool displays the decoded position of the transmission range switch (PRNDL). This information is then sent to the Instrument Panel Cluster (IPC) and is displayed to the operator.

TR Sw A/B/C/P: Displays HI/LOW,HI/LOW,HI/LOW,HI/LOW. These parameters are the four inputs from the Automatic Transmission (TR) Switch assembly. HI represents an ignition voltage signal. LOW represents a zero voltage signal.

Vehicle Speed: Range 0-255 km/h (0-255 mph). The VSS assembly signal is converted into metric or English units for display. The vehicle speed output from the PCM is 4,000 pulses per mile (PPM). The scan tool uses the class 2 serial data from the PCM in order to obtain vehicle speed. The instrument panel cluster, the cruise control module, and the multi-function alarm module use the 4,000 ppm output.