F - V

The Engine Scan Tool Data Definitions contains a brief description of all engine related parameters available on the scan tool. The list is in alphabetical order. A given parameter may appear in any one of the data lists. In some cases, the parameter may appear more than once or in more than one data list in order to group certain related parameters together.

FC Relay 1: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

FC Relay 2 and 3: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

Fans High Speed: The scan tool displays ON or OFF. The PCM is commanding all three fan control relays ON when the scan tool indicates ON. When all fan control relays are activated, both cooling fairs are enabled on high speed.

Fans Low Speed: The scan tool displays ON or OFF. The PCM is commanding fan control relay 1 ON when the scan tool indicates ON. When the PCM commands the fan control relay 1 ON, both fans are enabled on low speed.

Fuel Level: The scan tool displays 5.00 to 0 Volts. The PCM supplies a 5-volt signal circuit to the fuel sensor. The float inside the fuel tank is connected to a variable resistor which causes the signal voltage to change with fuel level. The PCM converts the signal voltage to a fuel level value. The scan tool displays close to 0.8 volts for an empty tank and close to 2.5 volts for a full tank.

Fuel Pump Ckt. Status: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

Fuel Pump Ckt History: The scan tool displays OK or Fault. This parameter saves the state of the driver circuit for this device.

Fuel Tank Pressure: The scan tool displays 17.5 to +7.5 in. H2O or (32.7 to +14.0 mm Hg). Fuel Tank Pressure is used extensively for EVAP purge control and EVAP system diagnostics.

Fuel Tank Pressure: The scan tool displays 0 to 5 volts. Fuel tank pressure is used extensively for EVAP system diagnostics.

Fuel Trim Cell: The scan tool range is 0-9. The fuel trim cell dependent upon the engine speed and the MAF sensor readings. A plot of RPM vs MAF is divided into 10 cells. The fuel trim cell indicates which cell is currently active.

Fuel Trim Learn: The scan tool displays Enabled or Disabled. When conditions are appropriate for enabling long term fuel trim corrections, the scan tool displays Enabled. This indicates that the long term fuel trim is responding to the short term fuel trim. If the scan tool displays Disabled, then long term fuel trim will not respond to changes in short term fuel trim.

Generator PWM: The scan tool displays 0-100 percent. This parameter indicates the pulse width of the voltage regulator's generator field control circuit. A high value indicates high electrical load.

HO2S Sensor 1: The scan tool displays Not Ready or Ready. This indicates the status of the fuel control exhaust oxygen sensor. The scan tool will indicate that the exhaust oxygen sensor is ready when the PCM detects a fluctuating heated oxygen sensor (HO2S) voltage sufficient to allow Closed Loop operation. This will not occur unless the exhaust oxygen sensor is warmed up.

HO2S Sensor 1: The scan tool range is 0-1000 mV. The HO2S Sensor 1 Bn 1 sensor 1 parameter represents the fuel control exhaust oxygen sensor output voltage. The voltage should fluctuate constantly within a range between about 50 mV (lean exhaust) and 800 mV (rich exhaust) while operating in Closed Loop.

HO2S Sensor 2: The scan tool range is 0-1000 mV. The HO2S Bn 1 Sensor 2 parameter is the post-catalyst exhaust oxygen sensor output voltage. Voltage should fluctuate within a range between about 50 mV (lean exhaust) and 800 mV (rich exhaust) while operating in Closed Loop. The post- catalyst HO2S output voltage will fluctuate slowly over a longer period of time, compared to the fuel control HO2S. This is due to the oxygen storage capability of an efficiently operating catalyst. If the voltage is fluctuating rapidly, and the catalyst is hot, low catalyst efficiency may be the cause.

HO2S XCounts: The scan tool range is 0-255. This figure indicates the number of times the HO2S 1 signal has crossed the 450 mV bias voltage during a 1 second interval. A HO2S 1 signal that almost never crosses the bias voltage could indicate a fuel trim problem, a faulty HO2S 1 circuit, or a faulty HO2S 1.

Hot Mode: The scan tool displays ON or OFF. The PCM has the ability to disable 3 injectors during an engine overtemperature condition. The engine enters this mode of operation if the ECT reaches 131°C (268°F). This protection mode permits the PCM to alternate between groups of 3 cylinders, thereby reducing engine temperature. ON indicates that the engine is operating in the alternating 3 cylinder mode.

Hot Open Loop: The scan tool displays Inactive or Active. Active indicates that the PCM has commanded Open Loop operation due to high engine temperature.

IAC Position: The scan tool range is 0-255 counts. This displays the commanded position of the idle air control pintle in counts. A larger number of counts means that more air is being commanded through the idle air passage. The idle air control (IAC) position should respond fairly quickly to changes in engine load to maintain desired idle RPM.

IAT: The scan tool range is -39°C to +140°C (-38°F to 284°F). The PCM converts the resistance of the intake air temperature (IAT) sensor to degrees. The PCM uses the IAT in order to adjust fuel delivery and spark timing according to incoming air density.

Ignition 1: The scan tool displays 0-25.5 Volts. The Ignition 1 represents the system voltage measured by the PCM at its ignition feed.

Injector Pulse Width: The scan tool range is 0-1000 sec. This indicates the amount of time the PCM is commanding each injector ON during each engine cycle. A longer injector pulse width will cause more fuel to be delivered. Injector pulse width should increase with increased engine load.

Knock Retard: The scan tool range is 0-16 degrees. Knock retard indicates the amount of spark the PCM removes from the ignition control (IC) spark advance in response to signals from the knock sensor.

Long Term FT: The scan tool displays -100 percent to +100 percent. 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 (decreased injector pulse width). A positive value significantly greater than 0 percent indicates that a lean condition exists and the PCM compensates by adding fuel (increased injector pulse width). Fuel trim values at maximum authority may indicate 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 the throttle position (TP) sensor, engine coolant, and MAF sensor inputs only.

MAF: The scan tool range is 0.0-655 gm/s. 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 0-31999 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: The scan tool range is 10-105 kPa / 0.0 to 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 updating the BARO reading and for an enabling factor for several of the diagnostics.

MIL: The scan tool displays ON or OFF. The scan tool indicates if the PCM is commanding the malfunction indicator lamp (MIL) ON.

Misfire Current Cyl. #1 - Misfire Current Cyl. #6: The scan tool range is 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 - Misfire History Cyl. #6: The scan tool range is 0-65535 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.

Non Volatile Memory: The scan tool indicates Pass or Fail. This parameter indicates the results of a PCM internal test.

O2 Heater Current: The scan tool displays HO2S Heater Current in Amps. This parameter displays the current draw of the HO2S 1 heater only. Typically, the HO2S heater current stabilizes at about 0.50A to 0.60A after operating temperature is reached. Initial current draw is slightly higher.

Power Enrichment: The scan tool displays Active or Inactive. Active 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

Short Term FT: The scan tool displays -100 percent to +100 percent. 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 range is -64 degrees to +64 degrees. This displays the amount of spark advance the PCM is commanding. The PCM computes spark advance using coolant temperature, RPM, engine load, vehicle speed, and requests for timing retard (from the KS system, TCS etc.). The PCM controls the timing and sequencing of the ignition system

Start Up ECT: The scan tool range is -40°C to +151°C (-40°F to +304°F). This indicates the engine coolant temperature at the time that the vehicle was started, and is used by the HO2S diagnostic to determine if the last startup was a cold start.

Start Up IAT: The scan tool range is -40°C to +151°C (-40°F to +304°F). This indicates the intake air temperature at the time that the vehicle was started. and is used by the HO2S diagnostic to determine if the last startup was a cold start.

Starter Enable Relay: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

Starter Relay Status: The scan tool displays ON or OFF. OFF indicates that the PCM is not allowing starter operation due to the engine running, excessive cranking time, trans not in P/N, or other factors.

TCC Sol.: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

TCM Calibration ID: This parameter provides an additional identification number for internal PCM calibrations. Unless this information is specifically requested, the regular PCM calibration ID part number (under ID Information) should be used.

TCM Software ID: This parameter provides an additional identification number for internal PCM software. Unless this information is specifically requested, the regular PCM calibration ID part number (under ID Information) should be used.

TCS Status: The scan tool displays Active, Allowed, Inhibited, Comm. Link Fail, Trac PWM Input, or Diag. Trac. PWM. Active indicates that a traction control event is occurring. Allowed indicates that the system is ready and operational but not currently controlling traction. Inhibited indicates that system operation is not allowed due to driver input or other factors. The remaining statuses indicate various malfunctions.

TCS Circuit Status: The scan tool displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

TCS Circuit History: The scan tool displays OK or Fault. This parameter saves the state of the driver circuit for this device.

TP Angle: The scan tool displays 0-100 percent. This parameter displays the amount of throttle opening in percent.

TP Sensor: 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.

TR Switch P / A / B / C: The 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. A unique combination of transaxle range inputs represents each position of the transaxle manual valve.

TWC Protection: The 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).

Tachometer Ckt. Status: The scan toot displays OK or Fault. This parameter indicates the state of the driver circuit for this device.

Tachometer Ckt. History: The scan tool displays OK or Fault. This parameter saves the state of the driver circuit for this device.

Total Misfire Current Count: The scan tool range is 0-99 counts. This 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: The scan tool range is 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: The scan tool range is 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.

Traction Control: The scan tool displays Active or Inactive. 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 event.

Transmission Range: The scan tool displays the transaxle gear position.

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.

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