stop start INFINITI FX35 2007 Owner's Guide

SYSTEM DESCRIPTION BRC-9
[VDC/TCS/ABS]
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Revision: 2006 July 2007 FX35/FX45
ABS

The Anti-Lock Braking System is a function that detects wheel revolution while braking, and it improves
handling stability during sudden braking by electrically preventing 4 wheel lock. Maneuverability is also
improved for avoiding obstacles.

If the electrical system malfunctions, then the fail-safe function starts, the ABS becomes inoperative, and
ABS warning lamp turns on.

Electrical system diagnosis by CONSULT-II is available.

During ABS operation, brake pedal lightly vibrates and a mechanical noise may be heard. This is normal.

When starting engine, or just after starting vehicle, brake pedal may vibrate or motor operating noises
may be heard from engine compartment. This is a normal status of operation check.

Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel,
or snow-covered (fresh, deep snow) roads.
EBD

The Electronic Brake Distribution is a function that detects subtle slippages between front and rear wheels
during braking, and it improves handling stability by electronically controlling the brake fluid pressure
which results in reduced rear wheel slippage.

In case of electrical system malfunction, the fail-safe function is activated, EBD and ABS becomes inoper-
ative, and ABS warning lamp and brake warning lamp are turned on.

Electrical system diagnosis by CONSULT-II is available.

During EBD operation, brake pedal lightly vibrates and a mechanical noise may be heard. This is normal.

When starting engine, or just after starting vehicle, brake pedal may vibrate or motor operating noises
may be heard from engine compartment. This is a normal status of operation check.

Stopping distance may be longer than that of vehicles without EBD when vehicle drives on rough, gravel,
or snow-covered (fresh, deep snow) roads.
Fail-Safe FunctionNFS000N8
VDC / TCS SYSTEM
In case of malfunction in the VDC/TCS system, VDC OFF indicator lamp and SLIP indicator lamp are turned
on, and the condition of vehicle is the same as the condition of vehicles without VDC/TCS system. In case of
malfunction in the VDC/TCS system, the ABS control continues to operate normally without VDC/TCS control.
CAUTION:
If the fail-safe function is activated, then perform the self-diagnosis for VDC/TCS/ABS control system.
ABS, EBD SYSTEM
In case of electrical malfunctions with the ABS, ABS warning lamp, VDC OFF indicator lamp and SLIP indica-
tor lamp will turn on. In case of electrical malfunctions with the EBD, brake warning lamp, ABS warning lamp,
VDC OFF indicator lamp and SLIP indicator lamp will turn on. Simultaneously, the VDC/TCS/ABS become one
of the following conditions of the fail-safe function.

For malfunction of ABS, only the EBD is activated and the condition of vehicle is the same condition of
vehicles without TCS/ABS system.
NOTE:
ABS self-diagnosis sound may be heard. That is a normal condition because a self-diagnosis for “Ignition
switch ON” and “The first starting” are being performed.

For malfunction of EBD, EBD and ABS become inoperative, and the condition of vehicle is the same as
the condition of vehicles without TCS/ABS, EBD system.

TROUBLE DIAGNOSIS BRC-25
[VDC/TCS/ABS]
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Revision: 2006 July 2007 FX35/FX45
Self-DiagnosisNFS000OI
DESCRIPTION

If an error is detected in the system, ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp
on the combination meter turn on. In this case, perform self-diagnosis as follows:

While CONSULT-II is used, ABS warning lamp, VDC OFF indicator lamp, SLIP indicator lamp may be
turned on in a case of no malfunctioning.
OPERATION PROCEDURE
1. Turn ignition switch OFF.
2. Perform “CONSULT-II Start Procedure”. Refer to GI-38, "
CONSULT-II Start Procedure" .
3. Turn ignition switch ON.
4. Start engine and drive at approximately 30 km/h (19 MPH) or more for approximately 1 minute.
5. After stopping vehicle, with the engine running, touch “ABS”, “SELF-DIAG RESULTS” in order on the CONSULT-II screen.
CAUTION:
If “START (NISSAN BASED VHCL)” is touched immediately after starting engine or turning on the
ignition switch, “ABS” might not be displayed in the “SELECT SYSTEM” screen. In this case,
repeat the operation from step 1. If it can not be shown after several attempts, ABS actuator and
electric unit (control unit) may have malfunctioned.
6. The self-diagnostic results are displayed. (If necessary, the self-diagnostic results can be printed out by touching “PRINT”.)

When “NO FAILURE” is displayed, check ABS warning lamp, VDC OFF indicator lamp and SLIP indica-
tor lamp.
7. Perform the appropriate inspection from the display item list, and repair or replace the malfunctioning component.
8. Drive the vehicle at approximately 30 km/h (19 MPH) or more for approximately 1 minute. CAUTION:
In a case that a wheel sensor is malfunctioning, ABS warning lamp, VDC OFF indicator lamp, SLIP
indicator lamp will turn on. If vehicle is not driven at approximately 30 km/h (19 MPH) or more for
at least approximately 1 minute after repair of the wheel sensor system, ABS warning lamp, VDC
OFF indicator lamp and SLIP indicator lamp may not turn off even if everything is normal. Check
again to make sure that there is no malfunction on other parts.
ERASE MEMORY
1. Turn ignition switch OFF.
2. Start the engine and touch “ABS”, “SELF-DIAG RESULTS”, “ERASE MEMORY” in order on the CON- SULT-II screen to erase the error memory.
CAUTION:
If the error memory is not erased, re-conduct the operation from step 4.
3. Perform self-diagnosis again, and make sure that diagnostic memory is erased.
4. Drive vehicle at 30 km/h (19 MPH) or more for approximately 1 minute as the final inspection, and make sure that the ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp turn off.
NOTE:
VDC OFF switch should not stay “ON” position.

TROUBLE DIAGNOSIS BRC-29
[VDC/TCS/ABS]
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Revision: 2006 July 2007 FX35/FX45
Data MonitorNFS000OJ
OPERATION PROCEDURE
1. After turning ignition switch OFF, perform “CONSULT-II Start Procedure”. Refer to GI-38, "CONSULT-II
Start Procedure" .
2. Turn ignition switch ON.
3. Touch “ABS”, “DATA MONITOR” in order on the CONSULT-II screen. CAUTION:
When “START (NISSAN BASED VHCL)” is touched immediately after starting engine or turning on
ignition switch, “ABS” might not be displayed in the “SELECT SYSTEM” screen. In this case,
repeat the operation from step 1.
4. Return to the Monitor Item Selection screen, and touch “ECU INPUT SIGNALS”, “MAIN SIGNALS” or “SELECTION FROM MENU”. Refer to the following information.
5. When “START” is touched, the data monitor screen is displayed.
DISPLAY ITEM LIST
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
GEAR ××× Gear position judged by PNP switch signal is displayed.
SLCT LVR POSI ××× Shift position judged by PNP switch signal.
FR RH SENSOR
[km/h (MPH)] ××× Wheel speed calculated by front RH wheel sensor signal is
displayed.
FR LH SENSOR
[km/h (MPH)] ××× Wheel speed calculated by front LH wheel sensor signal is
displayed.
RR RH SENSOR
[km/h (MPH)] ×××
Wheel speed calculated by rear RH wheel sensor signal is
displayed.
RR LH SENSOR
[km/h (MPH)] ××× Wheel speed calculated by rear LH wheel sensor signal is
displayed.
BATTERY VOLT
(V) ××× Voltage supplied to ABS actuator and electric unit (control
unit) is displayed.
ENGINE SPEED
(rpm) ×××
Engine speed judged by CAN communication signal is dis-
played.
DECEL G-SEN
(G) (AWD models) ××× Longitudinal acceleration detected by decel G sensor is dis-
played.
OFF SW
(ON/OFF)
×× × VDC OFF switch (ON/OFF) status is displayed.
STOP LAMP SW
(ON/OFF) ×××
Stop lamp switch (ON/OFF) status is displayed.
YAW RATE SEN
(d/s) ××
– Yaw rate detected by yaw rate sensor is displayed.
ACCEL POS SIG
(%) ×
–– Throttle valve open/close status judged by CAN communica-
tion signal is displayed.
STR ANGLE SIG
(deg) ×
–– Steering angle detected by steering angle sensor is dis-
played.
SIDE G-SENSOR
(m/s
2 ) ×
– – Lateral acceleration detected by side G sensor is displayed.
PRESS SENSOR
(bar) ×
–– Brake fluid pressure detected by pressure sensor is dis-
played.
FLUID LEV SW
(ON/OFF) ×
– – Brake fluid level switch (ON/OFF) status is displayed.
ABS WARN LAMP
(ON/OFF) –
×× ABS warning lamp (ON/OFF) status is displayed.
SLIP LAMP
(ON/OFF) –
×× SLIP indicator lamp (ON/OFF) status is displayed.

BRC-32
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: 2006 July 2007 FX35/FX45
TEST ITEM
Solenoid Valve
NOTE:
The example shown is for the front right wheel. The procedure for the other wheels is the same as given
below.

When performing an active test of the ABS function, select the
main item for each test item. In addition, when performing an
active test of the VDC/TCS function, select the item menu for
each test item.

For the ABS solenoid valve, touch “UP” “KEEP” “DOWN”, and
for the ABS solenoid valve (ACT), touch “UP” “ACTUATOR UP”
“ACTUATOR KEEP”, and check to make sure that all solenoid
valve (in, out) are operating as given in the table below.
*: ON for 1 to 2 seconds after the touch, and then OFF
NOTE:

If active test is performed with brake pedal depressed, pedal stroke may change. This is normal.

“TEST IS STOPPED” is displayed approximately 10 seconds after operation starts.

After “TEST IS STOPPED” is displayed, touch “BACK” and perform the test from the Step 8.
ABS Motor
Touch “ON” and “OFF” on the screen. Make sure ABS motor relay
operates as shown in table below.
NOTE:

If active test is performed with brake pedal depressed, pedal
stroke may change. This is normal.

“TEST IS STOPPED” is displayed approximately 10 seconds
after operation starts.
SFIA2097E
Operation ABS solenoid valve ABS solenoid valve (ACT)
UP KEEP DOWN UP ACTUATOR
UP ACTUATOR
KEEP
FR RH IN SOL OFF ON ON OFF OFF OFF
FR RH OUT SOL OFF OFF ON* OFF OFF OFF
CV 1 OFF OFF OFF OFF ON ON
SV 1 OFF OFF OFF OFF ON* OFF
Operation ON OFF
MOTOR RELAY ON OFF
ACTUATOR RLY ON ON
SFIA0593E

TROUBLE DIAGNOSIS BRC-33
[VDC/TCS/ABS]
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Revision: 2006 July 2007 FX35/FX45
For Fast and Accurate DiagnosisNFS000NH
PRECAUTIONS FOR DIAGNOSIS

Before performing diagnosis, always read precautions. Refer to BRC-11, "How to Proceed with Diagnosis"
.

If ABS actuator and electric unit (control unit), steering angle sensor, steering system parts or suspension
system parts have been replaced, or if alignment has been adjusted, be sure to adjust neutral position of
steering angle sensor before driving. Refer to BRC-6, "
Adjustment of Steering Angle Sensor Neutral Posi-
tion" .

After diagnosis is finished, be sure to erase memory. Refer to BRC-25, "Self-Diagnosis" .

When checking continuity and voltage between units, be sure to check for disconnection, looseness,
bend, or collapse of connector terminals. If any malfunction is found, repair or replace connector termi-
nals.

For intermittent symptoms, possible cause is malfunction in harness, harness connector, or terminals.
Move harness, harness connector, and terminals to check for poor connections.

If a circuit tester is used for the check, be careful not to forcibly extend any connector terminal.

To use CONSULT-II to perform self-diagnosis of ABS actuator and electric unit (control unit), active tests,
or work support, first stop work, then connect CONSULT-II and select “ABS”.

While self-diagnostic results of CONSULT-II shows malfunction, if CONSULT-II active test is performed,
an engine system error may be indicated. In this case, start engine to resume the normal screen.

VDC/TCS/ABS system electronically controls brake operation and engine output. The following symptoms
may be caused by normal operations:
Symptom Symptom description Result
Motor operation noise This is noise of motor inside ABS actuator and electric unit (control unit).
Slight noise may occur during VDC, TCS, and ABS operation.
Normal
When the vehicle speed goes over 20 km/h (12.5 MPH), motor and valves
operating noise may be heard. It happens only once after ignition switch is
ON. This is a normal status of the system operation check.
System operation check noise When engine starts, slight “click” noise may be heard from engine room.
This is normal and is part of system operation check. Normal
VDC/TCS operation
(SLIP indicator lamp blinking) TCS may activate momentarily if wheel speed changes when driving over
location where friction coefficient varies, when up/downshifting, or when
fully depressing accelerator pedal.
Normal
Cancel the VDC/TCS
function for the inspec-
tion on a chassis dyna-
mometer.
For inspection of speedometer or other instruments, press VDC OFF
switch to turn VDC/TCS function off.
When accelerator pedal is depressed on a chassis dynamometer (fixed
front-wheel type), vehicle speed will not increase. This is not normal. It is
result of TCS being activated by stationary front wheels. Warning lamp may
also illuminate to indicate “sensor system error”. This is also normal, and is
the result of the stationary front wheels being detected. To be certain,
restart engine, and drive vehicle at 30 km/h (19 MPH) or more. Make sure
warning lamp does not illuminate.
ABS operation
(Longer stopping distance) On roads with low friction coefficients, such as snowy roads or gravel
roads, vehicles with ABS may require a longer stopping distance. There-
fore, when driving on such roads, avoid overconfidence and keep speed
sufficiently low. Normal
Insufficient feeling of acceler-
ation Depending on road conditions, driver may feel that feeling of acceleration
is insufficient. This is because traction control, which controls engine and
brakes to achieve optimal traction, has the highest priority (for safety). As a
result, there may be times when acceleration is slightly less than usual for
the same accelerator pedal operation. Normal

BRC-54
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: 2006 July 2007 FX35/FX45
The Braking Distance is LongNFS000O0
CAUTION:
On slippery road surfaces, the stopping distance might be longer with the ABS operating than when
the ABS is not operating.
1. CHECK FUNCTION
Disconnect ABS actuator and electric unit (control unit) connector E56 to deactivate ABS. In this condition,
check stopping distance. After inspection, connect connector.
OK or NG
OK >>
Bleed air from brake piping.

Check brake system.
NG >> GO TO 2. CHECK WHEEL SENSOR. Refer to BRC-53, "
Excessive ABS Function Operation Fre-
quency" .
The ABS Function Does Not OperateNFS000O1
CAUTION:
The ABS does not operate when the speed is 10 km/h (6 MPH) or less.
1. CHECK ABS WARNING LAMP DISPLAY
Make sure warning lamp turns off approximately 2 seconds after the ignition switch is turned ON or when driv-
ing.
OK or NG
OK >> GO TO 2. CHECK WHEEL SENSOR. Refer to BRC-53, "Excessive ABS Function Operation Fre-
quency" .
NG >> Perform self-diagnosis. Refer to BRC-25, "
Self-Diagnosis" .
Pedal Vibration or ABS Operation Sound OccursNFS000O2
CAUTION:
Under the following conditions, when brake pedal is lightly depressed (just place a foot on it), ABS is
activated and vibration is felt. However, this is normal.

When shifting gears

When driving on slippery road

During cornering at high speed

When passing over bumps or grooves

When pulling away just after starting engine [at approximately 10 km/h (6 MPH) or higher]
1. SYMPTOM CHECK 1
Check if pedal vibration or operation sound occurs when engine is started.
OK or NG
OK >> Perform self-diagnosis. Refer to BRC-25, "Self-Diagnosis" .
NG >> GO TO 2.
2. SYMPTOM CHECK 2
Check symptom when electrical component (headlamps, etc.) switches are operated.
Does the symptom occur when the electrical component (head lamp, etc.) switches are operated?
YES >> Check if there is a radio, antenna, antenna lead wire, or wiring close to ABS actuator and electric unit (control unit) (or its wiring), and if there is, move it farther away.
NO >> GO TO 2. CHECK WHEEL SENSOR. Refer to BRC-53, "
Excessive ABS Function Operation Fre-
quency" .

DI-32
UNIFIED METER AND A/C AMP
Revision: 2006 July 2007 FX35/FX45
DATA MONITOR
Operation Procedure
1. Touch “DATA MONITOR” on “SELECT DIAG MODE” screen.
2. Touch either “MAIN SIGNALS” or “SELECTION FROM MENU” on the “DATA MONITOR” screen.
3. When “SELECTION FROM MENU” is selected, touch individual items to be monitored. When “MAIN SIG- NALS” is selected, main items will be monitored.
4. Touch “START”.
5. Touch “RECORD” while monitoring, then the status of the moni- tored item can be recorded. To stop recording, touch “STOP”.
Display Item List
X: Applicable
MAIN SIGNALS Monitors main signals.
SELECTION FROM MENU Selects and monitors individual signal.
SKIA4957E
Display item [Unit] MAIN
SIGNALS SELECTION
FROM MENU Contents
SPEED METER [km/h] or [mph] X X Displays the value of vehicle speed signal, which is input from
ABS actuator and electric unit (control unit).
SPEED OUTPUT [km/h] or [mph] X X Displays the value of vehicle speed signal, which is transmitted
to each unit with CAN communication.
TACHO METER [rpm] X X Displays the value of engine speed signal, which is input from
ECM.
W TEMP METER [ °C] or [ °F] X X Displays the value of engine coolant temperature signal, which
is input from ECM.
FUEL METER [lit.] X X Displays the value, which processes a resistance signal from
fuel gauge.
DISTANCE [km] or [mile] X X Displays the value, which is calculated by vehicle speed signal
from ABS actuator and electric unit (control unit), fuel gauge and
fuel consumption from ECM.
FUEL W/L [ON/OFF] X X Indicates [ON/OFF] condition of low-fuel warning lamp.
MIL [ON/OFF] X Indicates [ON/OFF] condition of malfunction indicator lamp.
AIR PRES W/L [ON/OFF] X Indicates [ON/OFF] condition of low tire pressure warning lamp.
SEAT BELT W/L [ON/OFF]
*1X Indicates [ON/OFF] condition of seat belt warning lamp.
BUZZER [ON/OFF] X X Indicates [ON/OFF] condition of buzzer.
DOOR W/L [ON/OFF] X Indicates [ON/OFF] condition of door warning lamp.
HI-BEAM IND [ON/OFF] X Indicates [ON/OFF] condition of high beam indicator.
TURN IND [ON/OFF] X Indicates [ON/OFF] condition of turn indicator.
OIL W/L [ON/OFF] X Indicates [ON/OFF] condition of oil pressure warning lamp.
VDC/TCS IND [ON/OFF] X Indicates [ON/OFF] condition of VDC OFF indicator lamp.
ABS W/L [ON/OFF] X Indicates [ON/OFF] condition of ABS warning lamp.
SLIP IND [ON/OFF] X Indicates [ON/OFF] condition of SLIP indicator lamp.
BRAKE W/L [ON/OFF]
*2X Indicates [ON/OFF] condition of brake warning lamp.
KEY G W/L [ON/OFF] X Indicates [ON/OFF] condition of key warning lamp (green).

DI-84
LANE DEPARTURE WARNING SYSTEM
Revision: 2006 July 2007 FX35/FX45
3. Touch “LDW” on “SELECT SYSTEM” screen.
If “LDW” is not displayed, go to GI-39, "
CONSULT-II Data Link
Connector (DLC) Circuit" .
4. Touch “WORK SUPPORT” on “SELECT DIAG MODE” screen.
5. Touch “AUTO AIM” on “SELECT WORK ITEM” screen.
6. The target should be accurately placed. The vehicle should be stopped.
After confirming the above, touch “START” to perform aiming.
CAUTION:
Never touch “START” when the target is not placed.
BCIA0030E
BCIA0031E
PKIB4696E
SKIB3146E

DI-120
REAR VIEW MONITOR
Revision: 2006 July 2007 FX35/FX45
CONSULT-II Function (REARVIEW CAMERA)NKS0031Y
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II BASIC OPERATION
Refer to GI-38, "CONSULT-II Start Procedure" .
WORK SUPPORT
Operation Procedure
1. Touch “DATA MONITOR” on “SELECT DIAG MODE” screen.
2. Touch either “SELCT GUIDELINE PATTERN” or “ADJ GUIDELINE POSITION” on the “WORK SUP- PORT” screen.
Refer to DI-121, "
SIDE DISTANCE GUIDELINE CORRECTION PROCEDURE" for detail.
DATA MONITOR
Operation Procedure
1. Touch “DATA MONITOR” on “SELECT DIAG MODE” screen.
2. Touch either “ALL SIGNALS” or “SELECTION FROM MENU” on the “DATA MONITOR” screen.
3. When “SELECTION FROM MENU” is selected, touch individual items to be monitored. When “ALL SIG- NALS” is selected, all items will be monitored.
4. Touch “START”.
5. Touch “RECORD” while monitoring, then the status of the monitored item can be recorded. To stop recording, touch “STOP”.
Display Item List
System Diagnosis mode Description Reference
page
REARVIEW CAMERA WORK SUPPORT
It can adjust the side distance guidelines which overlap the
rear view monitor image. DI-120
DATA MONITOR Displays rear view camera control unit input data in real
time. DI-120
ECU PART NUMBER Displays part number of rear view camera control unit. —
SELCT GUIDELINE PATTERN Side distance guideline is optional from two patterns.
ADJ GUIDELINE POSITION Side distance guideline is adjustable toward up and down, right and left.
ALL SIGNALS Monitors all signals.
SELECTION FROM MENU Selects and monitors individual signal.
Display item [Unit] ALL
SIGNALS SELECTION
FROM MENU Contents
R POSI SIG [ON/OFF] X X Indicates [ON/OFF] condition of R range position signal input.

ENGINE CONTROL SYSTEM EC-31
[VQ35DE]
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Revision: 2006 July 2007 FX35/FX45
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst 1 can then better reduce CO, HC and NOx emissions. This system uses air fuel ratio
(A/F) sensor 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 air fuel
ratio (A/F) sensor 1, refer to EC-239, "
DTC P0131, P0151 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 three way catalyst 1. Even if the switching characteris-
tics of air fuel ratio (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 air fuel ratio (A/F) sensor 1 or its circuit

Insufficient activation of air fuel ratio (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 the mixture ratio signal transmitted from air fuel ratio (A/F)
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during 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 compared 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 compensation used to maintain the mixture ratio at its theoretical
value. The signal from air fuel ratio (A/F) sensor 1 indicates whether the mixture ratio is RICH or LEAN com-
pared to the theoretical 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 carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
PBIB3020E