Scan Tool Testing and Procedures
Scan Tool DataAs the data values are standard values estimated on the basis of values obtained from the normally operating vehicles by using a scan tool, use them as reference values. Even when the vehicle is in good condition, there may be cases where the checked value does not fall within each specified data range. Therefore, judgment as abnormal should not be made by checking with these data alone.
Scan Tool Data (Part 1):
Scan Tool Data (Part 2):
Scan Tool Data (Part 3):
Also, conditions that can be checked by the scan tool are those detected by ECM and output from ECM as commands and there may be cases where the engine or actuator is not operating (in the condition) as indicated by the scan tool. Be sure to use the timing light to check the ignition timing. (Refer to Ignition Timing Inspection)
Scan Tool Data Definitions
COOLANT TEMP (ENGINE COOLANT TEMPERATURE, °C, °F)
It is detected by engine coolant temp. sensor.
INTAKE AIR TEMP. (°C, °F)
It is detected by intake air temp. sensor.
ENGINE SPEED (RPM)
It is computed by reference pulses from the camshaft position sensor.
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.
MAF (MASS AIR FLOW RATE, g/s, lb/min.)
It represents total mass of air entering intake manifold which is measured by mass air flow sensor.
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%
MAP (MANIFOLD ABSOLUTE PRESSURE, in.Hg, kPa)
This value indicates how much correction is necessary to keep the air/fuel mixture stoichiometrical.
It is detected by manifold absolute pressure sensor.
THROTTLE POS (ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is at fully closed position, throttle opening is indicated as 0 - 5% and 90 - 100% full open position.
BAROMETRIC PRESS (kPa, in.Hg)
This parameter represents a measurement of barometric air pressure and is used for altitude correction of the fuel injection quantity.
FUEL TANK LEVEL (%):
This parameter indicates approximate fuel level in fuel tank. As detectable range of fuel level sensor is set as 0 to 100%, however, with some models whose fuel tank capacity is smaller, indicated fuel level may be only 70% even when fuel tank is full.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage inputted from main relay to ECM.
BRAKE SW (ON / OFF)
This parameter indicates the state of the brake switch.
INTAKE TUNING SOL (INTAKE MANIFOLD TUNING VALVE, ON / OFF)
ON: Command for intake manifold tuning valve being output.
OFF: Command for intake manifold tuning valve not being output.
FUEL SYSTEM B1 (FUEL SYSTEM BANK-1 STATUS) FUEL SYSTEM B2 (FUEL SYSTEM BANK-2 STATUS)
Air/fuel ratio feedback loop status displayed as one of the followings.
OPEN: Open-loop has not yet satisfied conditions to go closed loop.
CLOSED: Closed-loop using oxygen sensor(s) as feedback for fuel control.
OPEN-DRIVE COND: Open-loop due to driving conditions (Power enrichment, etc.).
OPEN SYS FAULT: Open-loop due to detected system fault.
O2S SENSOR B1 S2 (HEATED OXYGEN SENSOR BANK-1 SENSOR-2, V) O2S SENSOR B2 S2 (HEATED OXYGEN SENSOR BANK-2 SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on exhaust pipe (post-catalyst). It is used to detect catalyst deterioration.
SHORT FT B1 (SHORT TERM FUEL TRIM BANK-1, %)SHORT FT B2 (SHORT TERM FUEL TRIM BANK-2, %)
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 BANK-1, %) LONG FT B2 (LONG TERM FUEL TRIM BANK-2, %)
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.
TOTAL FUEL TRIM B1 (TOTAL FUEL TRIM BANK-1, %) TOTAL FUEL TRIM B2 (TOTAL FUEL TRIM BANK-2, %)
The value of Total Fuel Trim is obtained by calculating based on values of Short Term Fuel Trim and Long Term Fuel Trim. This value indicates how much correction is necessary to keep the air/fuel mixture stoichiometrical.
A/F B1 S1 CURRENT (A/F SENSOR BANK-1 SENSOR-1 OUTPUT CURRENT, mA) A/F B2 S1 CURRENT (A/F SENSOR BANK-2 SENSOR-1 OUTPUT CURRENT, mA)
This parameter indicates output current of A/F sensor installed on exhaust manifold (pre-catalyst).
FUEL CUT (ON / OFF)
ON: Fuel being cut (output signal to injector is stopped)
OFF: Fuel not being cut
O2S B1 S2 ACT (HEATED OXYGEN SENSOR BANK-1 SENSOR-2, ACTIVE / INACTIVE) O2S B2 S2 ACT (HEATED OXYGEN SENSOR BANK-2 SENSOR-2, ACTIVE / INACTIVE)
This parameter indicates activation condition of HO2S-2
ACTIVE: Activating
INACTIVE: warming up or at stop.
A/F B1 S1 ACT (A/F SENSOR BANK-1 SENSOR-1, ACTIVE / INACTIVE) A/F B2 S1 ACT (A/F SENSOR BANK-2 SENSOR-1, ACTIVE / INACTIVE)
This parameter indicates activation condition of A/F sensor
ACTIVE: Activating
INACTIVE: warming up or at stop
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.
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.
EGR VALVE OPENING %)
This parameter indicates opening rate of EGR valve which controls the amount of EGR flow.
FUEL PUMP (ON / OFF)
ON is displayed when ECM activates the fuel pump via the fuel pump relay switch.
STARTER SW (ON / OFF)
This parameter indicates condition of starting motor relay output.
ON: Starting motor relay is ON
OFF: Starting motor relay is OFF
A/C PRESSURE (A/C REFRIGERANT ABSOLUTE PRESSURE, kPa)
This parameter indicates A/C refrigerant absolute pressure calculated by ECM.
A/C SWITCH (ON / OFF)
ON: Command for A/C operation being output from ECM to HVAC.
OFF: Command for A/C operation not being output.
A/C COMP RELAY (A/C COMPRESSOR RELAY, ON / OFF)
This parameter indicates the state of the A/C switch.
BLOWER FAN (ON / OFF)
This parameter indicates the state of the blower fan motor switch.
ELECTRIC LOAD (ON / OFF)
ON: Headlight, clearance light or rear defogger ON signal inputted.
OFF: Above electric loads all turned OFF.
PSP SWITCH (POWER STEERING PUMP PRESSURE SWITCH, ON / OFF)
ON: PSP SW is ON (P/S high pressure switch is ON)
OFF: PSP SW is OFF (P/S high pressure switch is OFF)
PNP SIGNAL (TRANSMISSION RANGE SENSOR, P/N or D range):
Whether the transmission range switch (P/N position switch) at P or N range or at R, D, 4, 3 or L range is displayed. If at P or N range, "P/N range" is displayed and if at R, D, 4, 3 or L range, "D" range is displayed.
RADIATOR COOLING FAN LOW (RADIATOR COOLING FAN CONTROL RELAY NO.1, ON / OFF)
ON: Command for radiator cooling fan control relay No.1 operation being output.
OFF: Command for relay operation not being output.
RDTR FAN NO.1 HIGH (RADIATOR COOLING FAN CONTROL RELAY NO.2, ON / OFF):
ON: Command for radiator cooling fan control relay No.2 which changes radiator cooling fan No.1 to high speed operation being output.
OFF: Command for relay operation not being output
RDTR FAN NO.2 HIGH (RADIATOR COOLING FAN CONTROL RELAY NO.3, ON / OFF)
ON: Command for radiator cooling fan control relay No.3 which changes radiator cooling fan No.2 to high speed operation being output.
OFF: Command for relay operation not being output
TP SENSOR 1 VOLT (THROTTLE POSITION SENSOR (MAIN) OUTPUT VOLTAGE, V)
The throttle position sensor (Main) reading provides throttle valve opening information in the form of voltage.
TP SENSOR 2 VOLT (THROTTLE POSITION SENSOR (SUB) OUTPUT VOLTAGE, V)
The throttle position sensor (Sub) reading provides throttle valve opening information in the form of voltage.
APP SENSOR 1 VOLT (ACCELERATOR PEDAL POSITION (APP) SENSOR (MAIN) OUTPUT VOLTAGE, V)
The APP Sensor (Main) reading provides accelerator pedal opening information in the form of voltage.
APP SENSOR 2 VOLT (ACCELERATOR PEDAL POSITION (APP) SENSOR (SUB) OUTPUT VOLTAGE, V)
The APP Sensor (Sub) reading provides accelerator pedal opening information in the form of voltage.
ACCEL POSITION (ABSOLUTE ACCELERATOR PEDAL POSITION, %)
When accelerator pedal is at fully released position, accelerator pedal is indicated as 0 - 5% and 90 - 100% fully depressed position.
TARGET THROTTLE POSI (TARGET THROTTLE VALVE POSITION, %)
Target Throttle Valve Position is ECM internal parameter which indicates the ECM requested throttle valve position.
IAC THROTTLE OPENING (IDLE AIR (SPEED) CONTROL THROTTLE VALVE OPENING, %):
This parameter indicates throttle valve opening of idle air control in %. (100% indicates the maximum idle air flow.)
THROTTLE MOTOR VOLT (V)
This parameter indicates power supply voltage of throttle actuator (motor) control circuit (input voltage from throttle actuator control relay).
CLOSED THROTTLE POS (CLOSED THROTTLE POSITION, ON / OFF)
This parameter reads ON when throttle valve is fully closed, or OFF when it is not fully closed.
THROTTLE MOTOR RELAY (ON / OFF)
ON: Throttle actuator (motor) control activated by ECM.
OFF: Throttle actuator (motor) control stopped by ECM.
VEHICLE SPEED (km/h, mph)
It is computed based on pulse signals from rear wheel speed sensor (RH, LH).
INJ PULSE WIDTH B1 (FUEL INJECTION PULSE WIDTH BANK-1, msec.)
(INJ PULSE WIDTH B2 (FUEL INJECTION PULSE WIDTH BANK-2, msec.))
This parameter indicates time of the injector drive (valve opening) pulse which is output from ECM.
EVAP VENT VALVE (EVAP CANISTER VENT VALVE, ON / OFF)
ON: ON command being output to EVAP canister vent valve.
OFF: ON command not being output.
LEAK CHECK PUMP (EVAP LEAK DETECTION PUMP, ON / OFF)
ON: ON command being output to EVAP leak detecting pump.
OFF: ON command not being output.
LEAK CHECK P SENSOR (EVAP LEAK CHECK PRESSURE SENSOR, in.Hg, kPa)
This parameter indicates the pressure in the EVAP system. It s equal to the barometric pressure while EVAP vent valve control is OFF (valve open). When EVAP leak check module operates, the pressure indicates EVAP system pressure.