Scan Tool Data Definitions Part 2

MAF: Scan Tool Range 0.0-655 gm/s. Mass Air Flow (MAF) is the MAF Input Frequency converted to grams of air per second. This indicates the amount of air entering the engine.

MAF Frequency: The scan tool displays 0-31,999 Hz. The PCM converts current draw needed by the MAF (to keep the hot wires at a constant temperature) into a frequency signal. The scan tool displays this frequency in Hertz.

MAP: Scan Tool Range 10-105 kPa/0.00-5.0 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 MAP sensor voltage and kPa reading. The PCM uses the MAP sensor signal for the following: (1) Updating the BARO reading; (2) Enabling factor for several of the diagnostics.

MIL: The scan tool displays On or Off. Scan tool indicates if the PCM has commanded the Malfunction Indicator Light (MIL) on.

Mileage Since DTC Cleared: The scan tool displays Km or Miles. This parameter indicates the mileage accumulated since an emission Diagnostic Trouble Code cleared. The PCM stores this mileage in the Freeze Frame and Failure records buffers.

Mileage Since First Fail: The scan tool displays Km or Miles. This parameter indicates the mileage accumulated since an emission Diagnostic Trouble Code first failed. The PCM stores this mileage in the Freeze Frame and Failure records buffers.

Mileage Since Last Fail: The scan tool displays Km or Miles. This parameter indicates the mileage accumulated since an emission Diagnostic Trouble Code last failed. The PCM stores this mileage in the Freeze Frame and Failure records buffers.

Misfire Cur. #1 - Misfire Cur. #8: Scan Tool Range 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 Failures: Scan tool displays 0-65535 Counts. The Misfire Failure counter shows the relative number of failed misfire tests since the misfire DTC (P0300) became active.

Misfire Hist. #1 - Misfire Hist. #8: Scan Tool Range 065535 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.

Misfiring Cylinder: The scan tool displays Prim. Cyl # 06 and Sec. Cyl # 08. When a multiple misfire occurs, the scan tool displays the cylinder with the most significant misfire under Prim. Cyl. The scan tool displays the least significant misfire under Sec. Cyl.

Misfire Passes: Scan tool displays 0-65535 Counts. The Misfire Pass counter shows the relative number of passed misfire tests since the misfire DTC (P0300) became active.

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: If the BCM and PCM loose communications with each other after sending the correct password, the PCM will goes a VTD Fail-Enable mode. This allows the driver to restart the vehicle on future ignition cycles until the communications between the BCM and PCM are restored.

PRND A, B, C, P: The scan tool displays a combination of switch patterns. Refer to DTC P0705 or P0706. P0705 P0706

PRND Position: The scan tool displays what position the gear shift lever is in.

PT Induced Chassis Pitch: The scan tool displays Active or Inactive. The scan tool displays Active when the PCM determines from various inputs (MAF, TP, APP, MAP, etc.) that occurring conditions would cause the vehicle's chassis to pitch. The scan tool displays Inactive under the normal operating conditions.

Reduced Engine Power: The scan tool displays Active or Inactive. The scan tool displays Active when the PCM receives a signal from the TAC module that a throttle actuator control system fault is occurring. The PCM limits the engine power.

Reverse: The scan tool displays Reverse. The Scan Tool indicates if the transmission gear selector lever is in reverse.

Reverse Inhibit: The scan tool displays Enabled or Disabled (Manual Transmission). When vehicle speed is above 4 mph, the PCM enables the reverse inhibit solenoid, and the scan tool indicates Enabled.

Revolutions w/Misfire: The scan tool displays Counts. The counts displayed are the number of misfire counts detected in the last misfire test.

ST FT Avg. 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 (Weighted) for the amount of which they are used. For example, the PCM rates an idle cell higher then a wide open cell. If a fueling malfunction is 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% indicates that the fuel system is rich and the PCM is reducing the fuel delivery (decreased injector pulse width). A positive value significantly greater than 0% indicates that a lean condition exists and the PCM is compensating by adding fuel (increased injector pulse width). When the average of the cells reach a predetermined high or low, a fuel trim DTC sets.

Short Term FT Bn1 and Bn2: 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%. The PCM adds fuel. If the oxygen sensor voltage stays mainly above the threshold, the short term fuel trim decreases below 0% 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: Scan Tool flange -64° to 64°. Displays the amount the PCM commands the spark advance on the IC circuit. The PCM computes the desired spark advance using the following: (1) Engine coolant temperature; (2) Engine speed (RPM); (3) Load; (4) Vehicle speed. The PCM adjusts the timing.

Start Up ECT: Scan Tool flange -39°C to 140°C (-38°F to 284°F). Indicates the Engine Coolant Temperature at the time you started the engine. The PCM Uses Start UP ECT for certain DTCs.

Stop Lamp Switch: The scan tool displays Applied or Released. When you depress the brake pedal, the scan tool displays applied and the stop lamps go on. When the brake pedal is at rest, the scan tool displays Released and the stop lamps go off.

TAC/PCM Communication: The scan tool displays OK or Fault. If the communication between the TAC Module and the PCM is interrupted the scan tool displays Fault. The scan tool displays OK under the normal operating conditions.

TCC/CC Brake Switch: The scan tool displays Applied or Released. This parameter indicates the state of the TCC/CC brake switch circuit input. Open indicates 0.0 voltage input (brake switch open, brake pedal applied). Closed indicates a B+ voltage input (brake switch closed, brake pedal released). When you apply the vehicle brakes, the scan tool display shows Applied. The torque converter clutch and cruise control disengages. When you release the vehicle brakes, the scan tool displays Released. This allows the cruise control to be resumed and the torque converter clutch to engage.

TCC Duty Cycle: The scan tool displays Disabled or Enabled. This parameter is the commanded state of the TCC PWM solenoid. The scan tool indicates Enabled when the commanded state of the solenoid is ON. When the solenoid is not on, the scan tool displays Disabled.

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

Total Misfire Current Count: Scan Tool Range 0-255. The Total Misfire Current Count indicates the total number of cylinder firing events that the PCM detected as being misfires during the last 200 crankshaft revolution sample period.

Total Misfire Failures Since First Fail: Scan Tool Range 0-65,535. The Total Misfire Failures Since First Fail indicates the total number of cylinder firing events that the PCM detected as being misfires since the first failure.

Total Misfire Passes Since First Fail: Scan Tool Range 0-65,535. The Total Misfire Passes Since First Fail indicates the total number of cylinder tiring events that the PCM detected as being good since the first fail.

TP Desired Angle: The scan tool displays 0-100%. The PCM indicates the desired throttle angle for conditions present at that time.

TP Indicated Angle: The scan tool displays 0-1 00%. The TP Indicated Angle displays in percentage the amount of throttle opening.

TP Sensor 1 Angle: The scan tool displays 0-1 00%. The scan tool displays the amount of throttle opening in percentage. Closed throttle displays 0% and wide open throttle displays near 100%.

TP Sensor 2 Angle: The scan tool displays 0-100%. The scan tool displays the amount of throttle opening in percentage. Closed throttle displays 0% and wide open throttle displays near 100%.

TP Sensor 1: The scan tool displays 0-5 Volts. The scan tool displays the amount of throttle opening in volts. Closed throttle displays about 1 volt and wide open throttle displays about 3.5 volts.

TP Sensor 2: The scan tool displays 5-0 Volts. The scan tool displays the amount of throttle opening in volts. Closed throttle displays about 4 volts and wide open throttle displays about 1.5 volts

TP Sensors Disagree: The scan tool displays Yes or No. When the TAC module receives a signal voltage from one of the throttle Position Sensors not in proper relationship to the other, the scan tool displays YES. The scan tool displays NO under normal operating conditions.

TP Sensor 1 Out of Range: The scan tool displays Yes or No. If the PCM detects that the voltage is below 1 volt at closed throttle or above 3.5 volts at wide open throttle, the scan tool displays YES. If the voltages are within specifications, the scan tool displays NO.

TP Sensor 2 Out of Range: The scan tool displays Yes or No. If the PCM detects that the voltage is above 4 volts at closed throttle or below 1.5 volts at wide open throttle, the scan tool displays YES. If the voltages are within specifications, the scan tool displays NO.

Traction Control: The scan tool displays Active or Inactive (If so equipped). The scan tool displays active if the PCM receives a signal from the Electronic Brake and Traction control Module (EBTCM) requesting torque reduction during a traction control maneuver.

Transmission Range: Scan tool displays the transaxle gear position.

Vehicle Speed: The scan tool displays km/h and mph. The vehicle speed sensor signal is converted into km/h and mph for display.

VTD Auto Learn Timer: The scan tool displays Active or 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 (10 minutes).

VTD Fuel Disable: The scan tool displays Active or Inactive. If the PCM has not received the correct password from the Body Control Module (BCM), the PCM will disable the fuel system, and Active will be displayed on the scan tool. The scan tool displays Inactive under normal running 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. With ignition off the scan tool displays NO.

Warm Up Cycles w/o Emis. Faults: Scan Tool flange 0-255. This parameter counts the number of warm up cycles without an emission fault present. The counter increments to 255 and roll back to 0.0 unless a fault occurs. If a fault occurs, the counter reverts back to 0.0 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 0.0.

Warm Up Cycles w/o Non - Emis. Faults: Scan Tool flange 0-255. This parameter counts the number of warm up cycles without a non-emission fault present. The counter increments to 255 and roll back to 0.0 unless a fault occurs. If a fault occurs, the counter reverts back to 0.0 until the fault is corrected. Clearing information with a scan tool or a loss of power to the PCM also resets the counter to 0.0.