Operation CHARM: Car repair manuals for everyone.

Part 2



Scan Tool Data Definitions - Continued

IAT Sensor
- The scan tool displays °C.
The PCM converts the resistance of the intake air temperature (IAT) sensor to degrees in the same manner as the engine coolant temperature (ECT) sensor. Intake air temp is used by the PCM to adjust fuel delivery and spark timing according to incoming air density.
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 sensor to degrees. The PCM uses the IAT in order to adjust fuel delivery and spark timing according to incoming air density.

Ignition 1 Signal
- This parameter displays the voltage measured at the ignition 1 circuit of the control module. Voltage is applied to the control module when the ignition switch is in the ignition 1 position.

Ignition Accessory Signal
- This parameter displays the state of the ignition 0 input to the control module from the ignition switch. The scan tool will display On when the ignition switch is in the ignition accessory position. The scan tool will display Off when the ignition switch is in any other position.

Ignition Off Time
- The Scan tool displays time in minutes.
This parameter is used by the control module to identify the amount of time that has passed. This parameter is used for various components and systems including throttle actuator control (TAC) system and the EVAP system.

Inj. 1 Disabled Due to Misfire
- This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 2 Disabled Due to Misfire
- This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 3 Disabled Due to Misfire
- This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 4 Disabled Due to Misfire
- This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 5 Disabled Due to Misfire
- This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Inj. 6 Disabled Due to Misfire
- This parameter displays the status of the fuel injector driver by the control module. The scan tool will display YES if the fuel injector is being disabled due to a misfire detection. The scan tool will display NO if the fuel injector is not being disabled by the control module due to a misfire.

Injector PWM Bank 1
- This parameter indicates the average commanded ON time for each injector on Bank 1 by the control module. The scan tool will display a larger value for a longer injector commanded ON time, causing more fuel to be delivered to the cylinders. The scan tool will display a smaller value for a shorter injector commanded ON time, causing less fuel to be delivered to the cylinders.

Injector PWM Bank 2
- This parameter indicates the average commanded ON time for each injector on Bank 2 by the control module. The scan tool will display a larger value for a longer injector commanded ON time, causing more fuel to be delivered to the cylinders. The scan tool will display a smaller value for a shorter injector commanded ON time, causing less fuel to be delivered to the cylinders.

Intake Manifold Pressure
- This parameter displays the pressure difference between the MAP and the barometric pressure (BARO) as calculated by the control module. The scan tool will display a higher value during high vacuum conditions, such as idle or deceleration. The scan tool will display a lower value during low vacuum conditions, such as wide open throttle or high load cruising.

Knock Detected Cyl. 1
- This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 2
- This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 3
- This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 4
- This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 5
- This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Detected Cyl. 6
- This parameter displays the status of each cylinder for knock detection by the control module. The scan tool will display YES if a knock condition has been detected related to that cylinder combustion event. The scan tool will display NO if there is no knock condition detected related to that cylinder combustion event.

Knock Retard
- The scan tool displays °.
Indicates the amount of spark the PCM is removing from ignition control (IC) spark advance in response to the signal from the knock sensors. The traction control system desired torque signal from the electronic brake and traction control module (EBTCM) may cause knock retard to display a value more than 0.0 degrees if traction control is active.

Long Term FT Bank 1
- The scan tool range is -99 to +99 percent. This parameter indicates the Long Term fuel trim (FT) correction for bank 1 as commanded by the PCM.
A change made to the fuel delivery will be indicated by the Long and Short Term FT values. The Short Term FT values change rapidly in response to the HO2S signal voltages. These changes fine tune the engine fueling. The Long Term FT values change in response to the trends in the Short Term FT. The Long Term FT makes coarse adjustments to the fueling in order to re-center and restore control to the Short Term FT. The Short Term FT and the Long Term FT can be monitored with a scan tool. A positive fuel trim value indicates that the ECM is adding fuel in order to compensate for a lean condition. A negative fuel trim value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.

Long Term FT Bank 2
- The scan tool range is -99 to 99 percent. This parameter indicates the Long Term FT correction for bank 2 as commanded by the PCM.
A change made to the fuel delivery will be indicated by the Long and Short Term FT values. The Short Term FT values change rapidly in response to the HO2S signal voltages. These changes fine tune the engine fueling. The Long Term FT values change in response to the trends in the Short Term FT. The Long Term FT makes coarse adjustments to the fueling in order to re-center and restore control to the Short Term FT. The Short Term FT and the Long Term FT can be monitored with a scan tool. A positive fuel trim value indicates that the ECM is adding fuel in order to compensate for a lean condition. A negative fuel trim value indicates that the ECM is reducing the amount of fuel in order to compensate for a rich condition.

Loop Status
- 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, ECT, and MAF sensor inputs only.

LT FT Test Avg. Bank 1
- This parameter is the average long term fuel trim for this bank as calculated by the control module. The scan tool will display a value more than 0 percent indicating that time is being added to the injector pulse width, increasing the amount of fuel to this bank of the engine. The scan tool will display a value of less than 0, indicating time is being subtracted from the injector pulse width, reducing the amount of fuel to this bank of the engine. A value of 0 percent indicates no compensation is required to operate the engine at the desired air/fuel ratio.

LT FT Test Avg. Bank 2
- This parameter is the average long term fuel trim for this bank as calculated by the control module. The scan tool will display a value more than 0 percent indicating that time is being added to the injector pulse width, increasing the amount of fuel to this bank of the engine. The scan tool will display a value of less than 0, indicating time is being subtracted from the injector pulse width, reducing the amount of fuel to this bank of the engine. A value of 0 percent indicates no compensation is required to operate the engine at the desired air/fuel ratio.

LT FT Test Avg. Bn. 1 w/o purge
- This parameter is calculated by the control module based on the Short Term FT value. The Long Term FT bank 1 is used for the long term correction of the fuel delivery in bank 1. The scan tool will display a high value for a large amount of long term fuel correction, and 0% for no long term fuel trim correction. The scan tool will display a negative value when fuel system is running too rich and fuel is being removed from the combustion event. The scan tool will display a positive value if the fuel system is running lean and fuel is being added to the combustion event

LT FT Test Avg. Bn. 2 w/o purge
- This parameter is calculated by the control module based on the Short Term FT value. The Long Term FT bank 1 is used for the long term correction of the fuel delivery in bank 1. The scan tool will display a high value for a large amount of long term fuel correction, and 0% for no long term fuel trim correction. The scan tool will display a negative value when fuel system is running too rich and fuel is being removed from the combustion event. The scan tool will display a positive value if the fuel system is running lean and fuel is being added to the combustion event

MAF Performance Test
- This parameter displays the status of the mass air flow (MAF) performance test by the control module. The scan tool will display OK if no fault is found. The scan tool will display Fault if the control module detects a fault during the test.

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

MAP Sensor
- The scan tool displays kPa
The MAP sensor measures the change in the intake manifold pressure which results from engine load and speed changes. As the intake manifold pressure increases, the air density in the intake also increases and additional fuel is required.
The scan tool displays a range of 10-105 kPa. The MAP sensor measures the absolute pressure in the intake manifold.

MAP Sensor
- The scan tool displays Volts
The MAP sensor measures the change in the intake manifold pressure which results from engine load and speed changes. As the intake manifold pressure increases, the air density in the intake also increases and additional fuel is required.
The scan tool displays a range of 10-105 kPa. The MAP sensor measures the absolute pressure in the intake manifold.

MAP Sensor Performance Test 1
- This parameter displays the status of the MAP performance test 1 by the control module. The scan tool will display OK if no fault is found. The scan tool will display Fault if the control module detects a fault during the test.

MAP Sensor Performance Test 2
- This parameter displays the status of the MAP performance test 2 by the control module. The scan tool will display OK if no fault is found. The scan tool will display Fault if the control module detects a fault during the test.

MIL Circuit Status
- This parameter displays the status of the output driver for the malfunction indicator lamp control circuit. The scan tool will display OK if the circuit is operating correctly. The scan tool will display Fault if there is an open, short to ground or a short to voltage on the circuit.

MIL Command
- This parameter displays the commanded state of the MIL control circuit. The malfunction indicator lamp should be on when the scan tool indicates the MIL Command is On. The malfunction indicator lamp should be off when the scan tool indicates the MIL Command is Off. The control module will command the MIL On when the ignition is ON with the engine OFF in order to perform a bulb check.

MIL Requested by DTC
- This parameter shows if the illumination of the MIL has been requested by a failed diagnostic trouble code (DTC).

Misfire Current Cyl. 1-6
- The scan tool displays 0-255 counts. The display shows the number of misfires that have been detected during the last 200 cylinder firing events. The counters may normally display some activity, but the activity should be nearly equal for all of the cylinders, and in low numbers.

Misfire History Cyl. 1-6
- The scan tool range is 0-255 counts. This parameter indicates 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 or DTC P0300 has become active. The misfire history counter will update every 200 cylinder firing events.