Scan Tool Data Definitions Part 2

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MIL: Scan Tool Displays ON or OFF. Indicates the PCM commanded state of the Malfunction Indicator Lamp.

Misfire Current Cyl #1/ Misfire Current Cyl #2 / Misfire Current Cyl #3/ Misfire Current Cyl #4/ Misfire Current Cyl #5 / Misfire Current Cyl #6: Scan Tool Range 0 to 198 Counts. The Misfire Current counters indicate the number of cylinder firing events detected as possible misfires on each cylinder during the last 200 crankshaft revolutions. The number that the counters display are twice the actual number of misfire events detected. The counters may normally display some activity, but the activity should be very low and nearly equal for all the cylinders.

Misfire History Cyl #1/ Misfire History Cyl #2/ Misfire History Cyl #3/ Misfire History Cyl #4/ Misfire History Cyl #5 / Misfire History Cyl #6: Scan Tool Range 0 to 65,535 Counts. The Misfire History counters indicate the total level of misfire that has been detected on each cylinder. The number that the counters display are twice the actual number of misfire events detected. The Misfire History counters will not update or show any activity until a misfire DTC (P0300) has become active. The Misfire History counters will be updated every time a 200 crankshaft revolution misfire test failure is detected. Misfiring Cylinder (Primary)/ Misfiring Cylinder (Secondary): Scan Tool Displays 0 or Cylinder #. If a misfire is being detected, Misfiring Cylinder displays the misfiring cylinder number(s).

Power Enrichment: Scan Tool Displays ACTIVE or INACTIVE. ACTIVE displayed indicates that the PCM has detected conditions appropriate to operate in Power Enrichment mode. The PCM will command Power Enrichment mode when a large increase in throttle position and load is detected. While in Power Enrichment, the PCM will increase the amount of fuel delivered by entering Open Loop and increasing the injector pulse width. This is done to prevent a possible sag or hesitation from occurring during acceleration.

Rich/Lean: Scan Tool Displays RICH or LEAN. Indicates whether oxygen sensor voltage is greater than a 600 mV threshold voltage (rich) or less than a 300 mV threshold voltage (lean). Should change constantly while in closed loop, indicating that the PCM is controlling the air/fuel mixture properly.

Short Term FT: Scan Tool Range -11% to 20%. 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 has mainly remained less than 450 mV, indicating a lean air/fuel mixture, short term fuel trim will increase into the positive range above 0% and the PCM will add fuel. If the oxygen sensor voltage stays mainly above the threshold, short term fuel trim will decrease below 0% into the negative range while the PCM reduces fuel delivery to compensate for the indicated rich condition. Under certain conditions such as extended idle and high ambient temperatures, canister purge may cause Short Term Fuel Trim to read in the negative range during normal operation. The PCM's maximum authority to control fuel trim allows a range between -11% and +20%. Fuel trim values at maximum authority may indicate an excessively rich or lean system.

Spark: Scan Tool Range -64 degrees to 64 degrees. Displays the spark timing being commanded by the PCM on the IC circuit. A negative (-) value indicates degrees Before Top Dead Center (BTDC) or spark advance; a positive value indicates degrees After Top Dead Center (ATDC) or spark retard. Because the ignition control module sets spark advance at a fixed value of 10 BTDC while operating in Bypass mode, the displayed Spark advance only reflects true spark timing when the PCM has commanded IC mode.

Start-Up ECT: Scan Tool Range -40°C to 151°C, -40°F to 304°F Indicates the Engine Coolant Temperature at the time that the vehicle was started. Used by the HO2S diagnostic to determine if the last startup was a cold start.

Start-Up IAT: Scan Tool Range -40°C to 151°C, -40°F to 304°F. Indicates the Intake Air Temperature at the time that the vehicle was started. Used by the HO2S diagnostic to determine if the last startup was a cold start.

Supercharger Boost: Scan Tool Range 0% to 100%. Represents the amount of manifold boost pressure commanded by the PCM. 100% displayed indicates full boost commanded.

Throttle At Idle: Scan Tool Displays YES or NO. Indicates whether the TP Angle being monitored by the PCM is at 0%.

Total Misfire Current Count: Scan Tool Range 0 to 99. Indicates the total number of cylinder firing events that were detected as being misfires during the last 200 crankshaft revolution sample period.

Total Misfire Failures Since First Fail: Scan Tool Range 0 to 65535 Counts. Indicates the number of 200 crankshaft revolution sample periods during which the level of misfire was sufficiently high to report a failure.

Total Misfire Passes Since First Fail: Scan Tool Range 0 to 65535 Counts. Indicates the number of 200 crankshaft revolution sample periods during which the level of misfire was sufficiently low to report a pass.

TP Angle: Scan Tool Range 0% to 100%. TP Angle is computed by the PCM from the TP Sensor voltage. TP Angle should display 0% at idle and 100% at wide open throttle.

TP Sensor: Scan Tool Range 0.00 to 5.00 Volts. The voltage being monitored by the PCM on the TP sensor signal circuit.

Traction Control: Scan Tool Displays ACTIVE or INACTIVE. ACTIVE displayed indicates that the traction control system is taking action to reduce drive wheel slippage.

Traction Control Desired Torque: Scan Tool Range 0% to 100%. Represents the PWM signal from the Electronic Brake and Traction Control Module. The EBTCM reduces the Traction Control Desired Torque signal pulse width when a drive wheel slippage situation is detected. The PCM monitors the Traction Control Desired Torque signal and reduces drive wheel slippage as necessary by retarding spark timing, decreasing boost sol. PWM, or increasing air/fuel ratio. The PCM can also turn OFF up to three fuel injectors if the Traction Control Desired Torque signal indicates a large enough amount of drive wheel slippage. A problem with the Traction Control Desired Torque signal should cause DTC P1571 to set.

Traction Control Torque: Scan Tool Range 0% to 100%. Represents the PWM signal which indicates the percent of available torque the engine is delivering to the drive wheels. The EBTCM monitors the Traction Control Torque signal to ensure that the PCM is responding properly to the Traction Control Desired Torque signal.

Transmission Range: Scan Tool Displays INVALID, PARK/NEUTRAL, REVERSE, DRIVE 4, DRIVE 3, DRIVE 2, or LOW. Transmission Range represents the decoded status of the four inputs from the Transaxle Range Switch Assembly. The combination of transaxle range inputs indicates the position of the transaxle manual valve.

TR Switch P / A / B / C: Scan Tool Displays HIGH or LOW. The TR Switch P / A / B / C display represents the states of the four inputs from the transaxle range switch. HIGH displayed indicates a B+ voltage signal being monitored at the PCM, LOW displayed indicates a grounded input signal. The combination of transaxle range inputs indicates the position of the transaxle manual valve.

TWC Diagnostic: Scan Tool Displays ENABLED or DISABLED. ENABLED displayed indicates that MAF, HO2S, ECT, or VSS DTCs that would disable the TWC diagnostic are not present.

TWC Monitor Test Counter: Scan Tool Range 0-49. The TWC monitor test counter increments while the TWC system diagnostic test is running and taking samples. When the TWC Monitor Test Counter reaches 49, the PCM will update the TWC diagnostic statistical filter. At this point, the TWC Monitor Test Counter will reset to 0 and begin incrementing again. The TWC Monitor Test Counter is most useful when verifying a Three-way catalytic converter replacement or any repair associated with the DTC P0420 diagnostic table.

TWC Protection: Scan Tool Displays ACTIVE or INACTIVE. ACTIVE displayed indicates that the PCM has detected conditions appropriate to operate in TWC Protection mode. This is determined based on Engine Load and Engine Coolant Temperature. While in TWC Protection, the PCM will decrease Air/Fuel Ratio to a value that depends on Mass Air Flow (higher Mass Airflow = lower Air/Fuel Ratio).

Vehicle Speed: Scan Tool Range 0-255 km/h, 0-155 mph. The vehicle speed sensor signal is converted into mph and km/h for display.

VTD Fuel Disable: Scan Tool Displays ACTIVE or INACTIVE. The PCM enables the fuel injectors if the the proper Theft Deterrent Fuel Enable signal from the Vehicle Theft Deterrent (VTD) Control Module is received. The scan tool normally displays INACTIVE. If the VTD Control Module does not send the correct Theft Deterrent Fuel Enable Signal to the PCM, the display will switch to ACTIVE and the fuel system may be disabled. Refer to DTCs P1626, P1629, or the Vehicle Theft Deterrent System for further diagnosis.