Scan Tool Data Definitions

SCAN TOOL DATA DEFINITIONS

COOLANT TEMP (ENGINE COOLANT TEMP, °C/°F)
It is detected by engine coolant temp. sensor.

INTAKE AIR TEMP (°C/°F)
It is detected by intake air temp. sensor.

DESIRE 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, the number is not valid.

CTP SWITCH (ON/OFF)
The CTP switch parameter will read ON when the throttle valve is fully closed, or OFF when the throttle is not fully closed.

IAC FLOW DUTY (%)
This parameter indicates ON (valve open) time rate within a certain set cycle of IAC valve which controls bypass airflow.

ENGINE SPEED (RPM)
It is computed by reference pulses from the Cam- shaft Position 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.

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.

BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage inputted from main relay to ECM.

MAF (MASS AIR FLOW RATE, g/s, Ib/min)
It represents total mass of air entering intake manifold which is measured by mass air flow sensor.

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 multi port fuel injection).

THROTTLE POS (ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is fully closed position, throttle opening is indicated as 0% and 100% for full open position.

TP SENSOR VOLT (TP SENSOR OUTPUT VOLTAGE, V)
Throttle Position Sensor reading provides throttle valve opening information in the form of voltage.

OXYGEN SENSOR B1 S1 (H02S-1 OUTPUT VOLTAGE, V)
It indicates output voltage of HO2S-1 installed on exhaust manifold (pre-catalyst).

OXYGEN SENSOR B1 S2 (H02S-2 OUTPUT VOLTAGE, V)
It indicates output voltage of H02S-2 installed on exhaust pipe (post-catalyst). It is used to detect catalyst deterioration.

FUEL SYSTEM (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%.

TOTAL FUEL TRIM (%)
The value of total fuel trim is obtained by multiplying 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.

CANIST PRG DUTY (EVAP CANISTER PURGE FLOW DUTY, %)
This parameter indicates valve ON (valve open) time rate within a certain set cycle of EVAP canister purge valve which controls the amount of EVAP purge.

VEHICLE SPEED (km/h, MPH)
It is computed based on pulse signals from vehicle speed sensor in combination meter.

FUEL CUT (ON/OFF)
ON:
Fuel being cut (output signal to injector is stopped).
OFF:
Fuel not being cut.

EGR VALVE (%)
This parameter indicates opening rate of EGR valve which controls the amount of EGR flow.

A/C SWITCH (ON/OFF)
ON:
Command for operation being output from A/C amplifier to compressor.
OFF:
Command for operation not being output.

PSP SWITCH (ON/OFF)
ON:
PSP switch detects P/S operation. (high PS pressure)
OFF:
PSP switch not detects P/S operation

PNP SIGNAL (TRANSMISSION RANGE SWITCH, P/N or D range)
Whether the transmission range switch (P/N position switch) at P or N range or at R, D, 2 or L range is displayed. If at P or N range, "P/N range" is displayed and if at R, D, 2 or L range, "D range" is displayed.

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.