G - W

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.

Generator L Terminal Signal Command: The scan tool displays Active or Inactive. The scan tool displays inactive if the PCM does not detect a correct voltage on the L-terminal circuit. The scan tool displays active under normal operating conditions.

HO2S Bank 1 and Bank 2 Sensor 1: The scan tool displays a range of 0-1,106 mV. The heated oxygen sensor (HO2S) bank 1 and bank 2 sensor 1 parameter represents the fuel control exhaust oxygen sensor output voltage. The voltage fluctuates constantly within a range between 10-1,000 mV, while operating in Closed Loop.

HO2S Bank 1 and Bank 2 Sensor 2: The scan tool displays a range of 0-1,106 mV. The HO2S bank 1 and bank 2 sensor 2 parameter represents the exhaust oxygen sensor output voltage. The voltage fluctuates constantly within a range between 10-1,000 mV, while operating in Closed Loop.

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

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

Inj. PWM Average Bank 1 and Bank 2: The scan tool displays a range of 0-1,000 milliseconds. The injector average indicates the amount of time the PCM commands each injector ON during each engine cycle. A longer injector pulse width causes more fuel to be delivered. The injector pulse width increases with an increased engine load.

Knock Retard: The scan tool displays a range of 0-16 degrees. Knock retard indicates the amount of spark the PCM removes from the ignition control (IC) spark advance in response to the signal from the knock sensors (KS).

Long Term FT Ave Bn1 and Bn2: 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.

Low Oil Lamp Command: The scan tool displays On or Off. The scan tool displays On when the PCM detects that there is a low oil level condition. The low oil lamp is then commanded ON by the PCM.

MAF Sensor: The scan tool displays a range of 0.0-655 g/s. The 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 temperature into a frequency signal. The scan tool displays this frequency in a hertz signal.

MAP Sensor: Scan Tool Range 10-105 kPa/ 0.0-5 volts. The 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 Command: The scan tool displays On or Off. The scan tool indicates if the PCM has commanded the malfunction indicator lamp (MIL) ON.

Misfire Current Cyl. #1 - #8: 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 - #8: 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.

Not Run Counter: The scan tool displays counts from 0-65,535. The scan tool displays the number of times a DTC diagnostic has not reached the predetermined criteria in order to run since the first DTC run failure.

Pass Counter: The scan tool displays counts from 0-65,535. The scan tool displays the number of times a DTC has passed.

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/VCM 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.

PNP Switch: The scan tool displays the gear shift lever position.

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.

Short Term FT Ave 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 IC circuit. The PCM computes the desired spark advance using the following: (1) 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 Pedal Switch: 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.

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 Brake Pedal Switch: The scan tool displays Applied or Released. This parameter indicates the state of the torque convener clutch/cruise control (TCC/CC) brake switch circuit input. Open indicates 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 displays Applied. The TCC/CC disengages. When you release the vehicle brakes, the scan tool displays Released. This allows the CC to be resumed and the TCC to engage.

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.

TCC PWM Solenoid Command: The scan tool displays 0-100 percent. This parameter is the commanded state of the TCC/PWM solenoid. The scan tool displays 100 percent when the commanded state of the solenoid is ON. The scan tool displays 0 percent when the solenoid is OFF.

TP Desired Angle: The scan tool displays 0-100 percent. The PCM indicates the desired throttle angle commanded by the vehicle operator.

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

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

TP Sensor Angle: The scan tool displays 0-100 percent. The scan tool displays the amount of throttle opening in percentage. Closed throttle displays 0 percent and WOT displays near 100 percent.

TP Sensor 1 Angle: The scan tool displays 0-100 percent. The scan tool displays the amount of throttle opening in percentage. Closed throttle displays 0 percent and WOT displays near 100 percent.

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

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 WOT displays above 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 WOT displays below 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 TP 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 WOT, 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 WOT, the scan tool displays YES. If the voltages are within specifications, the scan tool displays NO.

TR Switch: The scan tool displays the transmission gear position.

Vehicle Speed Sensor: The scan tool displays km/h and mph. The vehicle speed sensor signal is convened 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 Disabled: 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.