Scan Tool Data Definitions 2

SCAN TOOL DATA DEFINITIONS

Long Term Average FT1 and FT2: The scan tool displays percentage. This parameter indicates the average of all long term fuel trim cells. The short term fuel trim cells are rated, for the amount of which they are used. For example, an idle cell is rated higher than a wide open cell. If a fueling malfunction occurs in the idle cell and the wide open cell, the average would be more affected by the idle cell than the wide open cell. A negative value significantly below 0 percent indicates that the fuel system is rich and fuel delivery is being reduced. A positive value significantly more than 0 percent indicates that a lean condition exists and the PCM compensates by adding fuel. When the average of the cells reach a predetermined high or low, a fuel trim DTC sets.

Long Term FT Bank 1 and Bank 2: The scan tool displays percentage. The PCM derives the long term fuel trim from the short term fuel trim value. The long term fuel trim represents a long term correction of fuel delivery. A value of 0 percent indicates that fuel delivery requires no compensation in order to maintain the PCM commanded air/fuel ratio. A negative value significantly below 0 percent indicates that the fuel system is rich and the PCM is reducing the fuel delivery. A positive value significantly more than 0 percent indicates that a lean condition exists and the PCM compensates by adding fuel. Fuel trim values at maximum authority indicates an excessively rich or lean system.

Loop Status: The scan tool displays Open or Closed. Closed Loop indicates that the PCM is controlling fuel delivery according to oxygen sensor voltage. In Open Loop, the PCM ignores the oxygen sensor voltage and bases the amount of fuel to be delivered on throttle position (TP) sensor, engine coolant, and MAF sensor inputs only.

MAF Sensor: The scan tool displays a range of 0.0-655 g/s. MAF is the MAF input frequency converted to grams of air per second. This indicates the amount of air entering the engine.

MAF Sensor: The scan tool displays a range of 0-31,999 Hz. The MAF sensor is a hot wire type air flow sensor. The PCM converts current draw needed by the MAF to keep the hot wires at a constant into a frequency signal. The scan tool displays this frequency in a hertz signal.

MAP Sensor: The scan tool displays a range of 10-105 kPa (0.00-5.0 volts). The MAP sensor measures the absolute pressure in the intake manifold.

MIL Command: The scan tool displays On or Off. The scan tool indicates if the PCM has commanded the malfunction indicator lamp (MIL) ON.

Mileage Since DTC Cleared: The scan tool displays Kilometers or Miles. This parameter indicates the mileage accumulated since an emission diagnostic trouble code cleared. The PCM stores this mileage in the Freeze Frame/Failure Records buffers.

Misfire Counter Status: The scan tool displays Normal or Invalid. The scan tool displays Normal if the PCM detects a true misfire. If the scan tool displays Invalid, the PCM is detecting a rough road condition, or any condition that caused an abnormal crankshaft speed other than a true misfire.

Misfire Current Cyl. #1 - #6: The scan tool displays a range of 0-255 counts. The misfire current counters increment at a rate according to the number of possible misfires the PCM detects on each cylinder during the last 200 cylinder firing events. The counters may normally display some activity, but the activity should be nearly equal for all the cylinders.

Misfire History Cyl. #1 - #6: The scan tool displays a range of 0-65,535 counts. The misfire history counters display the total level of misfire that has been detected on each cylinder. The misfire history counters will not update or show any activity until a misfire DTC P0300 has become active. The misfire history counters will update every 200 cylinder firing events.

PCM Reset: The scan tool displays Yes or No. This parameter indicates when the internal PCM resets. The scan tool displays YES when an internal PCM reset occurred. The scan tool displays NO under the normal operating conditions.

PCM in VTD Fail Enable: The PCM displays Yes or No. The scan tool displays Yes if the body control module (BCM) and the PCM lose communications with each other after the BCM sends the correct password. The scan tool displays No if the BCM is communicating the correct password to the PCM.

SHORT Term FT Average Bn1 and Bn2: The scan tool displays percentage. This parameter indicates the average of the short term fuel trim cells. The short term fuel trim cells are rated for the amount of which they are used. For example, the PCM rates an idle cell higher than a wide open cell. If a fueling malfunction occurs in the idle cell and the wide open cell, the idle cell would affect more than then the wide open cell. A negative value significantly below 0 percent indicates that the fuel system is rich and the PCM is reducing the fuel delivery. A positive value significantly more than 0 percent indicates that a lean condition exists and the PCM is compensating by adding fuel. When the average of the cells reach a predetermined high or low, a fuel trim DTC sets.

Short Term FT Bank 1 and Bank 2: The scan tool displays percentage. The short term fuel trim represents a short term correction to fuel delivery by the PCM in response to the amount of time the fuel control oxygen sensor voltage spends above or below the 450 mV threshold. If the oxygen sensor voltage mainly remains less than 450 mV, indicating a lean air/fuel mixture, short term fuel trim increases into the positive range above 0 percent. The PCM adds fuel. If the oxygen sensor voltage stays mainly above the threshold, the short term fuel trim decreases below 0 percent into the negative range. The PCM reduces the fuel delivery in order to compensate for the indicated rich condition. Under certain conditions such as an extended idle and a high ambient temperature, the canister purge may cause the short term fuel trim to read in the negative range during normal operation. The fuel trim values at maximum authority may indicate an excessively rich or lean system.

Spark: The scan tool displays a range of -64 to +64 degrees. The scan tool displays the amount of degrees the PCM commands the spark advance on the ignition control (IC) circuit. The PCM computes the desired spark advance using the following: (1) engine coolant temperature (ECT), (2) engine speed (RPM), (3) load, (4) vehicle speed. The PCM adjusts the timing.

Start Up ECT: The scan tool displays a range of -39 to +140°C (-38 to +284°F). The scan tool displays the engine ECT at the time the engine was started. The PCM uses start-up ECT for certain DTCs.

Stoplamp Switch Signal: The scan tool displays Applied or Released. This parameter indicates the state of the brake switch circuit input. The scan tool displays Applied when you apply the vehicle brakes. The scan tool displays Released when you release the vehicle brakes.

TCC PWM Solenoid Command: The scan tool displays Disabled or Enabled. This parameter is the commanded state of the torque converter clutch (TCC) PWM solenoid. The scan tool displays Enabled when the commanded state of the solenoid is ON. The scan tool displays Disabled when the solenoid is OFF.

TCC Enable Solenoid Command: The scan tool displays Enabled or Disabled. The scan tool displays Enabled when the electrical system supplies a voltage to the TCC enable solenoid.

TP Sensor: The scan tool displays 0-100 percent. The scan tool displays the amount of throttle opening in percentage. The scan tool displays about 0 percent at closed throttle. The scan tool displays about 100 percent at wide open throttle (WOT).

TP Sensor: The scan tool displays 0-5 volts. The scan tool displays the amount of throttle opening in voltage. When the throttle is at a closed throttle the voltage is between 0.4-0.9 volts. When the throttle is at WOT the voltage is above 4.0 volts.

TR Switch: The scan tool displays transmission gear position.

Vehicle Speed Sensor: The scan tool displays km/h and mph. The vehicle speed sensor (VSS) signal is converted into km/h and mph for display on the scan tool.

VTD Auto Learn Timer: The scan tool displays Active/Inactive. The auto learn timer is the indication if the vehicle theft deterrent (VTD) system is in the learn mode and has not timed out.

VTD Fuel Disable: The scan tool displays Active/Inactive. If the PCM has not received the correct password from the BCM, the PCM disables the fuel system and the scan tool displays Active. The scan tool displays Inactive under normal operating conditions.

VTD Fuel Disable Until Ignition Off: The scan tool displays Yes or No. With the ignition ON and a VTD code present, the scan tool displays Yes.

Warm Ups w/o Emission Faults: The scan tool displays a range of 0-255. This parameter counts the number of warm up cycles without an emission fault present. The counter increments to 255 and rolls back to 0 unless a fault occurs. If a fault occurs, the counter reverts back to 0 until the fault is corrected. Clearing the information with a scan tool or a loss of power to the PCM also resets the counter to 0.

Warm Ups w/o Non - Emission Faults: The scan tool displays a range of 0-255. This parameter counts the number of warm up cycles without a non-emission fault present. The counter increments to 255 and rolls back to 0 unless a fault occurs. If a fault occurs, the counter reverts back to 0 until the fault is corrected. Clearing information with a scan tool or a loss of power to the PCM also resets the counter to 0.