Scan Tool Data Definitions. Chevrolet Metro 2001

For 1990-2009 cars

The scan tool data definitions are a brief description of all transmission-related parameters and of all engine-related parameters available on the scan tool. The list is arranged in the alphabetical order.

Air Conditioning: The parameter indicates ON if the PCM receives the A/C Idle-Up signal from the A/C compressor control module. This will allow the PCM to adjust the engine idle to maintain acceptable engine performance.
BARO: The scan tool range 0-125 kPa. The barometric pressure (BARO) sensor measures the changes in atmospheric pressure. This parameter indicates 95-105 kPa at sea level.
Battery Voltage: This parameter indicates battery positive voltage inputted from the Main Relay to the PCM.
Closed Throttle Switch: This parameter indicates CLOSED or OPEN.This reflects the state of the throttle valve. The closed throttle switch parameter is a calculation. The PCM uses the information from the TP sensor voltage in order to determine whether the throttle is OPEN or CLOSED.
Current Gear: Displays 1,2 or 3. This parameter indicates the current command state of the shift solenoid valves.
Desired Idle Speed: The Desired Idle Speed is a PCM internal parameter which indicates the PCM requested idle speed. If the engine is not running, this number is not valid.
Electrical Load Signal: The scan tool displays YES if there is electrical current.
Engine Speed: The scan tool range is 0-10,000 RPM. The PCM computes Engine speed from the ignitiON reference pulses. The Engine speed should remain close to desired idle under various engine loads with the engine idling.
ECT: The scan tool range is 80-90°C (176-194°F). The ECT sensor is a thermistor which changes internal resistance as temperature changes. If the sensor has high internal resistance high, the PCM monitors a high signal voltage and interprets the voltage as a cold engine. When the internal resistance decreases, the voltage signal decreases, and the PCM interprets the lower voltage as a warm engine.
Engine Coolant Fan: The scan tool will indicate ON/OFF, depending on a signal that is received by the PCM from the Engine Coolant Fan. The PCM will adjust if the Engine Coolant Fan will run ON/OFF.
Engine Load: The scan tool range is 10-18 percent. This parameter indicates engine load based on manifold absolute pressure. A higher percentage indicates a greater load on the engine.
Fuel Cutoff Signal: If the fuel is cut, the output signal to the fuel injector stops.The parameter indicates ON. If the fuel is not cut, the parameter indicates OFF.
Fuel Pump: This parameter indicates that the PCM is turning on the fuel pump by turning on the fuel pump relay. The PCM will turn the fuel pump relay ON for three seconds if the ignition is ON. The PCM will turn the fuel pump relay on continuously if the PCM receives reference pulses from the ignition module.
IAC Duty Cycle: The scan tool range is 17-30 percent. This scan tool parameter indicates the opening of the bypass air passage in terms of percentage. The opening of the bypass air passage determines the amount of airflow through the bypass air passage and is controlled by the IAC motor.
IAT: The scan tool range is -40°C to 120°C (-40°F to 250°F). The PCM converts the resistance of the intake air temperature sensor to degrees. The PCM uses the intake air temperature (IAT) in order to adjust fuel delivery and spark timing according to incoming air density.
Loop Status: The scan tool displays Open Loop or Closed Loop. Closed Loop indicates that the PCM is controlling fuel delivery according to oxygen sensor voltage. Open Loop indicates that the PCM ignores the oxygen sensor voltage.The PCM determines the fuel delivery according to the inputs from the TP sensor, from the ECT sensor, and from the MAP sensor.
MAP: The scan tool range is 0-125 kPa or 0.0-5.0 volts. The manifold absolute pressure (MAP) sensor measures the change in the intake manifold pressure from engine load, and from speed changes. When the intake manifold pressure increases, the intake vacuum decreases resulting in a higher kPa reading.
Monitor Shift Sol. 1: When the PCM energizes the shift solenoid 1, the scan tool displays ON, line pressure is relieved, and the 2-3 shift valve does not operate.
Monitor Shift Sol. 2: When the PCM energizes the shift solenoid 2, the scan tool displays ON, line pressure is relieved, and the 1-2 shift valve does not operate.
PNP: The scan tool displays P-N if the transmission is in PARK or in Neutral.The scan tool displays R- D-L if the transmission is in forward gears or in reverse gears.
Shift Solenoid 1: The scan tool displays ON/OFF. This parameter indicates the status of the 1-2 solenoid valve. If the transmission is in FIRST gear, the scan tool indicates ON. If the transmission is in SECOND gear or in THIRD gear, the scan tool indicates OFF.
Shift Solenoid 2: The scan tool displays ON/OFF. This parameter indicates the status of the 2-3 solenoid valve. If the transmission is in FIRST gear, the scan tool indicates ON. If the transmission is in SECOND or in THIRD gear, the scan tool indicates OFF.
Throttle Position Level: The scan tool will display 0 level until the throttle is taken off the idle position.
TP Sensor: The scan tool displays 0-5 volts. The scan tool displays how open the throttle is in volts. A closed throttle displays about 1 volt, and a wide-open throttle displays about 3.5 volts.
TP Angle: The scan tool displays 0-100 percent. The scan tool displays how open the throttle is in percentage. A closed throttle displays 0, and a wide-open throttle displays near 100 percent.
Transmission Range: The scan tool displays Park, Reverse Neutral, Drive, Drive 2, Low, and Invalid. The scan tool displays the decoded position of the transmission range switch. This information is sent to the Instrument Panel Cluster (IPC) and is displayed to the operator.
Vehicle Speed: The scan tool range is 0-200 km/h or 0-125 mph. This parameter displays the vehicle speed. The Powertrain Control Module (PCM) receives reference pulses from the Vehicle Speed Sensor (VSS) and converts the pulses into km/h and into mph.