Scan Tool Data Definitions 2

SCAN TOOL DATA DEFINITIONS

MAP Sensor: The scan tool range is 0-125 kPa/0.0-5.0 volts. The manifold absolute pressure (MAP) sensor measures the change in the intake manifold pressure from engine load, and speed changes. As intake manifold pressure increases, the intake vacuum decreases resulting in a higher kPa reading.

Misfire Current Cyl #1, #2, #3, #4, #5, #6: Indicates a count of the abnormal engine revolutions (misfire) for each cylinder.

Misfire History Cyl #1, #2, #3, #4, #5, #6: Indicates the stored or history count of the abnormal engine revolutions (misfire) for each cylinder.

Power Enrichment: This parameter displays the status of the operating mode of the control module used to increase fuel delivery during certain acceleration conditions.

Rough Road Detection: This parameter indicates Yes when the misfire diagnostic has determined that a rough road surface condition exists. Input from the CKP and CMP sensors indicates that the road surface may cause false engine misfire counts. During rough road detection the PCM uses certain filters in order to monitor engine misfire accurately.

Short Term FT Bank 1: The scan tool displays a positive or a negative percentage. The Short Term fuel trim (FT) represents a short-term correction to fuel delivery by the powertrain control module (PCM). The Short Term FT correction is driven by the fuel control oxygen sensor voltage. When the oxygen sensor (O2S) voltage remains less than 450 mV the PCM adds fuel and the Short Term FT parameter displays a positive percentage. When the oxygen sensor voltage stays at more than 450 mV the PCM subtracts fuel and the Short Term FT parameter displays a negative percentage. During an extended idle in high ambient temperatures the evaporative emission (EVAP) canister may purge, causing the Short Term FT to read in the negative range. This is a normal condition. Fuel trim values at maximum authority may indicate an excessively rich or lean system.

Short Term FT Bank 2: The scan tool displays a positive or a negative percentage. The Short Term fuel trim (FT) represents a short-term correction to fuel delivery by the powertrain control module (PCM). The Short Term FT correction is driven by the fuel control oxygen sensor voltage. When the oxygen sensor (O2S) voltage remains less than 450 mV the PCM adds fuel and the Short Term FT parameter displays a positive percentage. When the oxygen sensor voltage stays at more than 450 mV the PCM subtracts fuel and the Short Term FT parameter displays a negative percentage. During an extended idle in high ambient temperatures the evaporative emission (EVAP) canister may purge, causing the Short Term FT to read in the negative range. This is a normal condition. Fuel trim values at maximum authority may indicate an excessively rich or lean system.

Spark Advance: The scan tool range is -1 to +63 degrees. The scan tool displays the powertrain control module (PCM) controlled value that is being used to control the spark timing.

Start Up ECT: The scan tool range is -40 to +140°C (-40 to +284°F). This parameter displays what the ECT sensor temperature was when the engine was first started this ignition cycle.

TAC Limit Engine Power: The scan tool will indicate Yes when the throttle actuator control (TAC) system has fixed the engine speed below 1,500 RPM. A fault in the accelerator pedal position (APP) sensor circuit will cause the TAC Limit Engine Power

TAC Module Power Inhibit Feedback: This scan tool parameter displays the internal voltage of the TAC motor inhibit circuit. Normal circuit operation voltage is approximately 0.67 volts. Most DTC setting TAC system failures cause the inhibit circuit voltage to default to 0.0 volts. An open in the TAC module ground circuit can cause an inhibit circuit voltage of 0.96 volts.

Throttle Plate at Idle: This parameter indicates Yes when the position of throttle body throttle plate is at idle or the default closed position.

Throttle Plate at WOT: This parameter indicates Yes when the throttle body throttle plate is at the wide open throttle (WOT) position.

TP Angle: The scan tool range is 0-100 percent. The scan tool displays the amount of throttle opening in percentage. At closed throttle the scan tool displays zero percent. At wide open throttle (WOT) the scan tool displays approximately 80 percent. At normal engine idle speeds the TP angle is between 9-14 percent.

TPS Learned Value: The scan tool range is 0-100 percent. The TPS learned value is an assigned value by the PCM. The PCM calculates the value using the original TP position, plus any increase in angle as a result of a greater throttle plate opening to compensate for the buildup of carbon deposits. The typical TPS learned value is zero percent after reset. The value will increase as carbon deposits build up on the throttle plate.

Vehicle Speed: The scan tool range is 0-255 km/h (0-158 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 mph for display.