Scan Tool Data Definitions
FUEL SYSTEM B1 (FUEL SYSTEM STATUS)
Air/Fuel ratio feedback loop status displayed as either open or closed loop.
Open indicates that ECM ignores feedback from the exhaust oxygen sensor.
Closed indicates final injection duration is corrected for oxygen sensor feedback.
CALC LOAD (CALCULATED LOAD VALUE, %)
Engine load displayed as a percentage of maximum possible load. Value is calculated mathematically using the formula: actual (current) intake air volume ÷ maximum possible intake air volume x 100%.
COOLANT TEMP (ENGINE COOLANT TEMPERATURE, °C, °F)
It is detected by engine coolant temp. sensor
SHORT FT B1 (SHORT TERM FUEL TRIM, %)
Short term fuel trim value represents short term corrections to the air/fuel mixture computation. A value of 0 indicates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies an enleanment correction.
LONG FT B1 (LONG TERM FUEL TRIM, %)
Long term fuel trim Value represents long term corrections to the air/fuel mixture computation. A value of 0 indicates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies an enleanment correction.
MAP (INTAKE MANIFOLD ABSOLUTE PRESSURE, kPa, in.Hg)
It is detected by manifold absolute pressure sensor and used (among other things) to compute engine load.
ENGINE SPEED (rpm)
It is computed by reference pulses from crankshaft position sensor.
VEHICLE SPEED (km/h, MPH)
It is computed based on pulse signals from vehicle speed sensor.
IGNITION ADVANCE (IGNITION TIMING ADVANCE FOR NO.1 CYLINDER, °)
Ignition timing of NO.1 cylinder is commanded by ECM. The actual ignition timing should be checked by using the timing light.
INTAKE AIR TEMP. (°C, °F)
It is detected by intake air temp. sensor and used to determine the amount of air passing into the intake manifold as air density varies with temperature.
MAF (MASS AIR FLOW RATE, g/s, lb/min)
It represents total mass of air entering intake manifold which is measured mass air flow sensor.
THROTTLE POS (ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is at fully closed position, throttle opening is indicated as 0% and 100% full open position.
OXYGEN SENSOR B1 S1 (HEATED OXYGEN SENSOR-1, V)
It indicates output voltage of HO2S-1 installed on exhaust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2 (HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on exhaust pipe (post-catalyst). It is used to detect catalyst deterioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM internal parameter which indicates the ECM requested idle. If the engine is not running, this number is not valid.
TP SENSOR VOLT (THROTTLE POSITION SENSOR OUTPUT VOLTAGE, V)
The Throttle Position Sensor reading provides throttle valve opening information in the form of voltage.
INJ PULSE WIDTH (FUEL INJECTION PULSE WIDTH, msec.)
This parameter indicates time of the injector drive (valve opening) pulse which is output from ECM (but injector drive time of NO.1 cylinder for multiport fuel injection).
IAC FLOW DUTY (IDLE AIR (SPEED) CONTROL DUTY, %)
This parameter indicates current flow time rate within a certain set cycle of IAC valve (valve opening rate) which controls the amount of bypass air (idle speed).
TOTAL FUEL TRIM (%)
The value of Total Fuel Trim is obtained by putting values of short Term Fuel Trim and Long Term Fuel Trim together. This value indicates how much correction is necessary to keep the air/fuel mixture stoichiometrical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage inputted from main relay to ECM.
CANIST PURGE DUTY (EVAP CANISTER PURGE FLOW DUTY, %)
This parameter indicates valve ON (valve open) time rate within a certain set cycle of EVAP purge solenoid valve which controls the amount of EVAP purge.
0% means that the purge valve is completely closed while 100% is a fully open valve.
CLOSED THROTTLE POSITION (ON / OFF)
This parameter will read ON when throttle valve is fully closed, or OFF when the throttle is not fully closed.
FUEL CUT (ON / OFF)
ON: Fuel being cut (output signal to injector is stopped)
OFF: Fuel not being cut
A/C CONDENSER FAN (A/C CONDENSER FAN RELAY, ON / OFF)
ON: Command for condenser fan relay operation being output.
OFF: Command for relay operation not being output.
ELECTRIC LOAD (ON / OFF)
ON: Headlight, small light or rear window defogger ON signal inputted.
OFF: Above electric loads all turned OFF.
A/C SWITCH (ON / OFF)
ON: Command for A/C operation being output from ECM to A/C amplifier.
OFF: Command for A/C operation not being output.
FUEL TANK LEVEL (%)
This parameter indicates approximate fuel level in the fuel tank. As the detectable range of the fuel level sensor is set as 0 to 100%, however, with some models whose fuel tank capacity is smaller, the indicated fuel level may be only 70% even when the fuel tank is full.
STEP EGR FLOW DUTY (%)
This parameter indicates opening rate of EGR valve which controls the amount of EGR flow.
PSP SW (ON / OFF)
The Power Steering Pressure switch parameter displays ON when steering wheel is turned all the way to the right or left.
BAROMETRIC PRES (kPa, in.Hg)
This parameter represents a measurement of barometric air pressure and is used for altitude correction of the fuel injection quantity and IAC valve control.
FUEL PUMP (ON / OFF)
ON is displayed when the ECM activates the fuel pump via the fuel pump relay switch.
BRAKE SWITCH (ON / OFF)
This parameter indicates the state of the brake switch.
BLOWER FAN (ON / OFF)
This parameter indicates the state of the blower fan motor switch.
A/C COMP RELAY (A/C COMPRESSOR RELAY, ON / OFF)
This parameter indicates the state of the A/C switch.
VVT GAP (TARGET-ACTUAL POSITION, °)
It is calculated using the formula: target valve timing advance – actual valve timing advance.