Misfire Data

Misfire Data

Engine Speed - Range (O-16384 RPM): The VCM computes the Engine Speed from the fuel control reference input. The speed should remain close to the desired idle under the various engines loads with the engine idling.

Misfire Current Cyl. #1: The scan tool will display the number of current cylinder misfires.

Misfire Current Cyl. #2: The scan tool will display the number of current cylinder misfires.

Misfire Current Cyl. #3: The scan tool will display the number of current cylinder misfires.

Misfire Current Cyl. #4: The scan tool will display the number of current cylinder misfires.

Misfire Current Cyl. #5: The scan tool will display the number of current cylinder misfires.

Misfire Current Cyl. #6: The scan tool will display the number of current cylinder misfires.

Cycles of Misfire Data - Range (0-100): Displays which engine cycle of the 100 engine cycle test the VCM is collecting data for.

Total Misfire Current Count - Range (0-255): The Total Misfire Current Count indicates the total number of cylinder firing events that the VCM detected as being misfires during the last 200 crankshaft revolution sample period. Misfire is diagnosed using crankshaft speed variations in relation with engine speed and load data.

Engine Speed - Range 0-16384 RPM: The VCM computes the Engine Speed from the fuel control reference input. The speed should remain close to the desired idle under the various engines loads with the engine idling.

Misfire History Cyl. #1: The scan tool will display the number of history cylinder misfires.

Misfire History Cyl. #2: The scan tool will display the number of history cylinder misfires.

Misfire History Cyl. #3: The scan tool will display the number of history cylinder misfires.

Misfire History Cyl. #4: The scan tool will display the number of history cylinder misfires.

Misfire History Cyl. #5: The scan tool will display the number of history cylinder misfires.

Misfire History Cyl. #6: The scan tool will display the number of history cylinder misfires.

Inj. PWM Avg. Bank 1 - Range (0-499 ms): The Inj. Avg. Bank 1 indicates the injector on time that the VCM is commanding.

Inj. PWM Avg. Bank 2 - Range (0-499 ms): The Inj. Avg. Bank 2 indicates the injector on time that the VCM is commanding.

Total Misfire Failures - Range (0-255): The Total Misfire Failures indicates the total number of cylinder firing events that the VCM determined as misfires during the last 200 crankshaft revolution sample.

Total Misfire Passes Since First Failure - Range (0-65,535): The Total Misfire Passes Since First Fail indicates the total number of cylinder firing events that the VCM detected as being good since the first fail.

TP Angle - Range (0-100%): The VCM computes the TP Angle from the TP signal voltage input. The TP Angle should read 0% at idle. AT 0%, the TP voltage will read below 0.90 volts. The TP Angle should read 100% at Wide Open Throttle.

ECT - Range -40°-215°C (-40°-419°F): The Engine Coolant Temperature (ECT) sensor is mounted in the intake the intake manifold. The ECT sends the engine temperature information to the VCM. The VCM supplies 5 volts to the ECT sensor circuit. The sensor is a thermistor which changes the internal resistance as the temperature changes. When the sensor is cold meaning the internal resistance is high, the VCM monitors a high voltage signal. The VCM interprets the high voltage signal as a cold engine. As the sensor warms meaning the internal resistance decreases, the voltage signal decreases. The VCM interprets the lower resistance as a warm engine.

Manifold Absolute Pressure (MAP) Sensor - Range (0.0-5.0 Volts): The MAP sensor produces a low signal voltage when the manifold pressure is low. A low manifold pressure means a high vacuum. The MAP sensor produces a high signal voltage when the manifold pressure is high. A high manifold pressure means a low vacuum. With the ignition ON and the engine stopped, the manifold pressure equals the atmospheric pressure causing the signal voltage to be high. The VCM uses this information as an indication of the vehicle's altitude. This information is referred to as the BARO. Comparison of this BARO reading with a known good vehicle with the same sensor is a good way to check accuracy of a suspect sensor. The readings should read the same +0.4 volt.

Manifold Absolute Pressure (MAP) - Range (10 kPa-104 kPa): The Manifold Absolute Pressure (MAP) sensor measures the change in the intake manifold pressure from the engine load and the speed changes. As the intake manifold pressure increases, the air density in the intake manifold also increases. Additional fuel is required.

Engine Load - Range (0-100%): The VCM determines the engine load based upon the engine speed and MAF sensor readings. Engine Load increases with any increase in RPM and/or airflow.

MAF - Range (0-512 g/s): The VCM convents the Mass Air Flow sensor input signal into grams per second. The MAF indicates the amount of air entering the engine.

Brake Switch - Range (Open/Closed): The Brake Switch indicates the status of the brake switch.

A/C Request - Range (Yes/No): The scan tool indicates the state of the A/C request input circuit. The VCM uses the A/C request signal in order to determine whether A/C compressor operation has been requested.

A/C Relay - Range (Yes/No): The scan tool indicates whether the A/C relay control circuit has been commanded ON.

KS Active Counter - Range (0-255): The KS Active Counter indicates the number of knock occurrences that occur within one-eighth of a second.

Spark - Range (-96 Degrees to -255 Degrees): The Spark Advance is a display of the spark advance calculation which the VCM is programming into the ignition system. The VCM computes the desired spark advance using data such as the engine temperature, the RPM, the load, the vehicle speed, and the operating mode.

Loop Status - Range (Open Loop/Closed Loop): The scan tool indicates whether the vehicle is in an open or closed loop state. The VCM uses HO2S information for determining fuel delivery during closed loop.

Vehicle Speed - km/h-Range (0-255): The MPH - km/h indicates in MPH and in km/h how fast the drive wheels are turning.

Clutch Switch - Range (ON/OFF): The scan tool indicates the current clutch switch state. When the clutch pedal is depressed the cruise control is disabled.

TCC Enable - Range (Yes/No): The scan tool indicates whether or not the VCM commanded the TCC enable solenoid to an active state.

TCC Duty Cycle - Range (0-100%): The scan tool indicates the amount that the VCM commands the TCC ON. The TCC solenoid is pulse modulated to provide a determined amount of pressure, which is translated into a percentage of the supply pressure. An open solenoid circuit would cause the duty cycle to be fixed at maximum.


DTC Set this Ignition - Range (Yes/No): The scan tool indicates whether or not any DTC has set during the current ignition cycle.

Engine Run Time - Range (0:00:0-18:12:15) Hours: Minutes: Seconds: The Engine Run Time is a measure of how long the engine has run during this ignition cycle. When the engine stops running, the timer resets to zero.