air condition INFINITI QX56 2011 Factory Service Manual

SYSTEMEC-37
< SYSTEM DESCRIPTION > [VK56VD]
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*1: This sensor is not used to control the engine system under normal conditions.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The adoption of the direct fuel injection method enables
more accurate adjustment of fuel injection quantity by
injecting atomized high-pressure fuel directly into the cylinder. This method allows high-powered engine, low
fuel consumption, and emissions-reduction.
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). T he amount of fuel injected is a program value in the
ECM memory. The program value is preset by engi ne operating conditions. These conditions are determined
by input signals (for engine speed and intake air and fuel rail pressure) from the crankshaft position sensor,
camshaft position sensor, mass air flow sensor and the fuel rail pressure sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compens ated to improve engine performance under various operat-
ing conditions as listed below.
 During warm-up
 When starting the engine
 During acceleration
 Hot-engine operation
 When selector lever position is changed from N to D
 High-load, high-speed operation

 During deceleration
 During high engine speed operation
FUEL INJECTION CONTROL
Stratified-charge Combustion
Stratified-charge combustion is a combustion method wh ich enables extremely lean combustion by injecting
fuel in the latter half of a compression process, coll ecting combustible air-fuel around the spark plug, and form-
ing fuel-free airspace around the mixture.
Right after a start with the engine cold, the catalyst warm-up is accelerated by stratified-charge combustion.
Homogeneous Combustion
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor Engine speed*
2
Fuel injection
& mixture ratio
controlFuel injector
Camshaft position sensor Camshaft position
Mass air flow sensor Amount of intake air
Intake air temperature sensor Intake air temperature
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Fuel rail pressure sensor Fuel rail pressure
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
TCM Gear position
Battery
Battery voltage*
2
Knock sensor Engine knocking condition
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit) VDC/TCS operation command
A/C auto amp. A/C ON signal
Combination meter Vehicle speed
Revision: 2010 May2011 QX56

EC-38
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
Homogeneous combustion is a combustion method that fuel
is injected during intake process so that combus-
tion occurs in the entire combustion chamber , as is common with conventional methods.
As for a start except for starts with the engine cold, homogeneous combustion occurs.
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov ides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can better reduce CO , HC and NOx emissions. This system uses A/F sen-
sor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The ECM adjusts the
injection pulse width according to the sensor voltage signal. For more information about A/F sensor 1, refer to
EC-21, "
Air Fuel Ratio (A/F) Sensor 1". This maintains the mixture ratio within the range of stoichiometric
(ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the th ree way catalyst (manifold). Even if the switching
characteristics of A/F sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal from heated
oxygen sensor 2.
 Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
- Deceleration and acceleration
- High-load, high-speed operation
- Malfunction of A/F sensor 1 or its circuit
- Insufficient activation of A/F sensor 1 at low engine coolant temperature
- High engine coolant temperature
- During warm-up
- After shifting from N to D
- When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors t he mixture ratio signal transmitted from A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM c ontrols the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mi xture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass ai r flow sensor hot wire) and characteristic changes dur-
ing operation (i.e., fuel injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value co mpared against the basic injection duration. Fuel trim
includes “short-term fuel trim” and “long-term fuel trim”.
“Short term fuel trim” is the short-term fuel compensati on used to maintain the mixture ratio at its theoretical
value. The signal from A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-
oretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an increase in
fuel volume if it is lean.
“Long-term fuel trim” is overall fuel compensation carri ed out over time to compensate for continual deviation
of the “short-term fuel trim” from the central value. Continual deviation will occur due to individual engine differ-
ences, wear over time and changes in the usage environment.
FUEL INJECTION TIMING
Sequential Direct Injection Gasoline System
PBIB2793E
Revision: 2010 May2011 QX56

SYSTEMEC-41
< SYSTEM DESCRIPTION > [VK56VD]
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COOLING FAN CONTROL : System DiagramINFOID:0000000006217703
COOLING FAN CONTROL : System DescriptionINFOID:0000000006217704
INPUT/OUTPUT SIGNAL CHART
*1: The ECM determines the engine speed by the signals of crankshaft position and camshaft position.
*2: This signal is sent to ECM via the CAN communication line.
SYSTEM DESCRIPTION
 Based on a signal transmitted from each sensor, ECM calc
ulates a target fan speed responsive to a driving
condition. In addition, ECM calculates a fan pulley speed according to an engine speed and transmits a cool-
ing fan request signal to IPDM E/R via the CAN comm unication line to satisfy the target fan speed. Then,
IPDM E/R transmits ON/OFF pulse duty signal to electrically-controlled cooling fan coupling.
The cooling fan speed sensor detects a cooling f an speed and transmits the detection result to ECM.
 ECM judges the start signal state from the engine speed signal and battery voltage.
ELECTRIC IGNITION SYSTEM
JSBIA0237GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor Engine speed*
1
Cooling fan speed request
signal*2
IPDM E/R
↓
Electrically-controlled cooling fan
coupling
Camshaft position sensor Camshaft position
Engine coolant temperature sensor Engine coolant temperature
Refrigerant pressure sensor Refrigerant pressure
Intake air temperature sensor Intake air temperature
Battery Battery voltage
Combination meter
Vehicle speed signal*
2
BCMA/C switch signal*2
Cooling fan speed sensor Cooling fan speed
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EC-42
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
ELECTRIC IGNITION SYSTEM : System Diagram
INFOID:0000000006217705
ELECTRIC IGNITION SYSTEM : System DescriptionINFOID:0000000006217706
INPUT/OUTPUT SIGNAL CHART
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM via the CAN communication line.
SYSTEM DESCRIPTION
Ignition order: 1 - 8 - 7 - 3 - 6 - 5 - 4 - 2
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Comput-
ing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is re vised by the ECM according to the other data stored in
the ECM.
 At starting
 During warm-up
 At idle
 At low battery voltage
 During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
JPBIA3271GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor Engine speed*
1
Piston position
Ignition timing
controlIgnition coil
(with power transistor)
Camshaft position sensor
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
TCM Gear position
Battery
Battery voltage*
1
Knock sensor Engine knocking condition
Combination meterVehicle speed*
2
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EC-46
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM via the CAN communication line.
SYSTEM DESCRIPTION
The evaporative emission system is used to reduce hydr
ocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplis hed by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into t he EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not oper ating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating. EVAP canister purge volume contro l solenoid valve is controlled by ECM. When the
engine operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is
proportionally regulated as the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.
AIR CONDITIONING CUT CONTROL
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor
Camshaft position sensor  Engine speed*
1
 Piston position
EVAP canister
purge flow controlEVAP canister purge volume
control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio
feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
EVAP control system pressure sensor Pressure in purge line
Combination meter Vehicle speed*
2
PBIB1631E
Revision: 2010 May2011 QX56

SYSTEMEC-47
< SYSTEM DESCRIPTION > [VK56VD]
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AIR CONDITIONING CUT CONTROL : System DiagramINFOID:0000000006217713
AIR CONDITIONING CUT CONTROL : System DescriptionINFOID:0000000006217714
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM via the CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.
 When the accelerator pedal is fully depressed.
 When cranking the engine.
 At high engine speeds.
 When the engine coolant temperature becomes excessively high.
 When operating power steering during low engine speed or low vehicle speed.
 When engine speed is excessively low.
 When refrigerant pressure is excessively low or high.
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
JMBIA1457GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor
Camshaft position sensor Engine speed*
2
Air conditioner cut
controlIPDM E/R
↓
A/C relay
↓
Compressor
Engine coolant temperature sensor Engine coolant temperature
Accelerator pedal position sensor Accelerator pedal position
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
A/C auto amp.A/C ON signal*
1
A/C evaporator temperature*1
Target A/C evaporator temperature*1
Blower fan ON signal
Combination meter Vehicle speed*
1
Revision: 2010 May2011 QX56

EC-52
< SYSTEM DESCRIPTION >[VK56VD]
DIAGNOSIS SYSTEM (ECM)
DIAGNOSIS SYSTEM (ECM)
DIAGNOSIS DESCRIPTION
DIAGNOSIS DESCRIPTION : 1st Trip Detect
ion Logic and Two Trip Detection Logic
INFOID:0000000006217722
When a malfunction is detected for the first time, 1st tr ip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not illuminate at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL illuminates. The MIL illu minates at the same time when the DTC is stored.
<2nd trip> The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is per-
formed during vehicle operation. Specific on board diagnos tic items will cause the ECM to illuminate or blink
the MIL, and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
DIAGNOSIS DESCRIPTION : DT C and Freeze Frame DataINFOID:0000000006217723
DTC AND 1ST TRIP DTC
The 1st trip DTC (whose number is the same as the DT C number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously , and the 1st trip DTC did not recur, the 1st trip DTC
will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is saved in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunc tion is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are saved in the ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL light s up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. Fo r malfunctions that blink or light up the MIL during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
For malfunctions in which 1st trip DTCs are displayed, refer to EC-98, "
DTC Index". These items are required
by legal regulations to continuous ly monitor the system/component. In addi tion, the items monitored non-con-
tinuously are also displayed on CONSULT-III.
1st trip DTC is specified in Service $07 of SAE J1979/ ISO 15031-5. 1st trip DTC detection occurs without illu-
minating the MIL and therefore does not warn the driver of a malfunction.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to EC-135, "
Work Flow". Then perform DTC Confirma-
tion Procedure or Component Function Check to try to duplicate the malfunction. If the malfunction is dupli-
cated, the item requires repair.
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, absolute throttle position, base
fuel schedule and intake air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are ca lled freeze frame data and displayed on CONSULT-III or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-III screen.
Items MIL DTC 1st trip DTC
1st trip 2nd trip 1st trip
displaying 2nd trip
displaying 1st trip
displaying 2nd trip
displaying
Blinking Illuminate Blinking Illuminate
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0308 is
being detected ×
——— — — ×—
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0308 is
being detected ——
×—— ×——
One trip detection diagnoses (Re-
fer to EC-98, "
DTC Index".) —
×—— ×———
Except above — — — ×— ×× —
Revision: 2010 May2011 QX56

EC-64
< SYSTEM DESCRIPTION >[VK56VD]
DIAGNOSIS SYSTEM (ECM)
*: This function is not necessary
in the usual service procedure.
SELF-DIAG RESULTS MODE
Self Diagnostic Item
Regarding items of DTC and 1st trip DTC, refer to EC-98, "DTC Index".
How to Read DTC and 1st Trip DTC
DTCs and 1st trip DTCs related to the malfunction are displayed in “Self-diag results”.
 When ECM detects a 1st trip DTC, “1t” is displayed for “TIME”.
 When ECM has detected a current DTC, “0” is displayed for “TIME”.
 If “TIME” is neither “0” nor “1t”, the DTC occurred in the past and ECM shows the number of times the vehi-
cle has been driven since the last detection of the DTC.
How to Erase DTC and 1st Trip DTC
NOTE:
 If the ignition switch stays ON after repair work, be su re to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
 If the DTC is not for A/T related items (see EC-98, "
DTC Index"), skip step 1.
1. Erase DTC in TCM. Refer to TM-60, "
Diagnosis Description".
2. Select “ENGINE” with CONSULT-III.
3. Select “SELF-DIAG RESULTS”.
4. Touch “ERASE”. (DTC in ECM will be erased.)
WORK ITEM CONDITION USAGE
IDLE AIR VOL LEARN  THE IDLE AIR VOLUME THAT KEEPS THE ENGINE
WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM. When learning the idle air volume
EVAP SYSTEM CLOSE CLOSE THE EVAP CANISTER VENT CONTROL VALVE IN
ORDER TO MAKE EVAP SYSTEM CLOSE UNDER THE
FOLLOWING CONDITIONS.
 IGN SW ON
 ENGINE NOT RUNNING
 AMBIENT TEMPERATURE IS ABOVE 0
°C (32 °F).
 NO VACUUM AND NO HIGH PRESSURE IN EVAP SYS-
TEM
 FUEL TANK TEMP. IS MORE THAN 0 °C (32 °F).
 WITHIN 10 MINUTES AFTER STARTING “EVAP SYS-
TEM CLOSE”
 WHEN TRYING TO EXECUTE “EVAP SYSTEM CLOSE” UNDER THE CONDITION EXCEPT ABOVE, CONSULT-
III WILL DISCONTINUE IT AND DISPLAY APPROPRI-
ATE INSTRUCTION.
NOTE:
WHEN STARTING ENGINE, CONSULT-III MAY DIS-
PLAY “BATTERY VOLTAGE IS LOW. CHARGE BAT-
TERY”, EVEN WHEN USING A CHARGED BATTERY. When detecting EVAP vapor leak
in the EVAP system
FUEL PRESSURE RELEASE  FUEL PUMP WILL STOP BY TOUCHING “START” DUR-
ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS. When releasing fuel pressure from
fuel line
SELF-LEARNING CONT  THE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT. When clearing mixture ratio self-
learning value
TARGET IDLE RPM ADJ*  IDLE CONDITION When setting target idle speed
VIN REGISTRATION  IN THIS MODE, VIN IS REGISTERED IN ECM. When registering VIN in ECM
TARGET IGN TIM ADJ*  IDLE CONDITION When adjusting target ignition tim-
ing
CLSD THL POS LEARN  IGNITION ON AND ENGINE STOPPED. When learning the throttle valve
closed position
VVEL POS SEN ADJ PREP  USE THIS ITEM ONLY WHEN REPLACING VVEL ACTU-
ATOR SUB ASSEMBLY.
 IGNITION ON AND ENGINE STOPPED. When adjusting VVEL control
shaft position sensor
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (ECM)EC-65
< SYSTEM DESCRIPTION > [VK56VD]
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Freeze Frame Data and 1st Trip Freeze Frame Data
*: The items are the same as those of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×
: Applicable
Freeze frame data
item* Description
DIAG TROUBLE
CODE
[PXXXX]  The engine control compon
ent part/control system has a trouble code the is displayed as PXXXX. (Refer to
EC-98, "
DTC Index".)
CAL/LD VALUE [%]  The calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP [ °C]
or [ °F]  The engine coolant temperature at the moment a malfunction is detected is displayed.
L-FUEL TRM-B1 [%]  “Long-term fuel trim” at the moment a malfunction is detected is displayed.
 The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule than short-term fuel trim.
L-FUEL TRM-B2 [%]
S-FUEL TRM-B1 [%]  “Short-term fuel trim” at the moment a malfunction is detected is displayed.
 The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel sched-ule.
S-FUEL TRM-B2 [%]
ENGINE SPEED [rpm]  The engine
speed at the moment a malfunction is detected is displayed.
VEHICL SPEED
[km/h] or [mph]  The vehicle speed at the moment a malfunction is detected is displayed.
INT MANI PRES [kPa]  These items are displayed but are not applicable to this model.
ABSOL TH·P/S [%]  The throttle valve opening angle at the moment a malfunction is detected is displayed.
B/FUEL SCHDL
[msec]  The base fuel schedule at the moment a malfunction is detected is displayed.
INT/A TEMP SE [ °C]
or [ °F]  The intake air temperature at the moment a malfunction is detected is displayed.
FUEL SYS-B1  “Fuel injection system status” at the moment a malfunction is detected is displayed.  One of the following mode is displayed.
Mode2: Open loop due to detected system malfunction
Mode3: Open loop due to driving conditions (power enrichment, deceleration enleanment)
Mode4: Closed loop - using oxygen sensor(s) as feedback for fuel control
Mode5: Open loop - has not yet satisfied condition to go to closed loop
FUEL SYS-B2
COMBUST CONDI-
TION
 These items are displayed but are not applicable to this model.
Monitored item Unit Description Remarks
ENG SPEED rpm  Indicates the engine speed computed from the sig-
nal of the crankshaft position sensor and camshaft
position sensor.  Accuracy becomes poor if
engine speed drops below
the idle rpm.
 If the signal is interrupted while the engine is running,
an abnormal value may be
indicated.
MAS A/F SE-B1 V  The signal voltage of the mass air flow sensor is
displayed.  When the engine is stopped,
a certain value is indicated.
 When engine is running,
specification range is indicat-
ed in “SPEC”.
B/FUEL SCHDL ms  “Base fuel schedule” indicates the fuel injection
pulse width programmed into ECM, prior to any
learned on board correction.  When engine is running,
specification range is indicat-
ed in “SPEC”.
Revision: 2010 May2011 QX56

EC-66
< SYSTEM DESCRIPTION >[VK56VD]
DIAGNOSIS SYSTEM (ECM)
A/F ALPHA-B1
% The mean value of the air-fuel ratio feedback cor-
rection factor per cycle is indicated.  When the engine is stopped,
a certain value is indicated.
 This data also includes the data for the air-fuel ratio
learning control.
 When engine is running, specification range is indicat-
ed in “SPEC”.
A/F ALPHA-B2
COOLAN TEMP/S
°C or °F  The engine coolant temperature (determined by
the signal voltage of the engine coolant tempera-
ture sensor) is displayed.  When the engine coolant
temperature sensor is open
or short-circuited, ECM en-
ters fail-safe mode. The en-
gine coolant temperature
determined by the ECM is
displayed.
A/F SEN1 (B1) V The A/F signal computed from the input signal of
the air fuel ratio (A/F) sensor 1 is displayed.
A/F SEN1 (B2)
HO2S2 (B1)
V The signal voltage of the heated oxygen sensor 2
is displayed.
HO2S2 (B2)
HO2S2 MNTR (B1)
RICH/LEAN Display of heated oxygen sensor 2 signal:
RICH: means the amount of oxygen after three
way catalyst is relatively small.
LEAN: means the amount of oxygen after three
way catalyst is relatively large.  When the engine is stopped,
a certain value is indicated.
HO2S2 MNTR (B2)
VHCL SPEED SE km/h or mph  The vehicle speed computed from the vehicle
speed signal sent from combination meter is dis-
played.
BATTERY VOLT V  The power supply voltage of ECM is displayed.
ACCEL SEN 1
V The accelerator pedal position sensor signal volt-
age is displayed.  ACCEL SEN 2 signal is con-
verted by ECM internally.
Thus, they differs from ECM
terminal voltage signal.
ACCEL SEN 2
TP SEN 1-B1
V The throttle position sensor signal voltage is dis-
played.  TP SEN 2-B1 signal is con-
verted by ECM internally.
Thus, they differs from ECM
terminal voltage signal.
TP SEN 2-B1
FUEL T/TMP SE
°C or °F  The fuel temperature (determined by the signal
voltage of the fuel tank temperature sensor) is dis-
played.
EVAP SYS PRES V  The signal voltage of EVAP control system pres-
sure sensor is displayed.
FUEL LEVEL SE V  The signal voltage of the fuel level sensor is dis-
played.
START SIGNAL ON/OFF  Indicates start signal status [ON/OFF] computed
by the ECM according to the signals of engine
speed and battery voltage.  After starting the engine,
[OFF] is displayed regard-
less of the starter signal.
CLSD THL POS ON/OFF  Indicates idle position [ON/OFF] computed by
ECM according to the accelerator pedal position
sensor signal.
AIR COND SIG ON/OFF  Indicates [ON/OFF] condition of the air conditioner
switch as determined by the air conditioner signal.
PW/ST SIGNAL ON/OFF  [ON/OFF] condition of the power steering system
(determined by the signal voltage of the power
steering pressure sensor signal) is indicated.
Monitored item Unit Description Remarks
Revision: 2010 May2011 QX56