+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 the refrigerant pressure is excessively high or low.
Fuel Cut Control (at no load & high engine
speed)
DESCRIPTIONNJEC0017Input/Output Signal ChartNJEC0017S01
Sensor Input Signal to ECMECM func-
tionActuator
Vehicle speed sensor Vehicle speed
Fuel cut
controlInjectors PNP switch Neutral position
Throttle position sensor Throttle position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS) Engine speed
Camshaft position sensor (PHASE) Engine speed and cylinder number
If the engine speed is above 3,950 rpm with no load, (for example, in Neutral and engine speed over 4,000
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,150 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under ªMultiport Fuel Injection (MFI) Systemº,
EC-29.
Evaporative Emission System
DESCRIPTIONNJEC0018
SEF916WA
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating 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.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONQG
Air Conditioning Cut Control (Cont'd)
EC-33
Positive Crankcase Ventilation
DESCRIPTIONNJEC0022
SEF921W
This system returns blow-by gas to the intake collector.
The positive crankcase ventilation (PCV) valve is provided to conduct crankcase blow-by gas to the intake
manifold.
During partial throttle operation of the engine, the intake manifold sucks the blow-by gas through the PCV
valve.
Normally, the capacity of the valve is sufficient to handle any blow-by and a small amount of ventilating air.
The ventilating air is then drawn from the air duct into the crankcase. In this process the air passes through
the hose connecting air inlet tubes to rocker cover.
Under full-throttle condition, the manifold vacuum is insufficient to draw the blow-by flow through the valve.
The flow goes through the hose connection in the reverse direction.
On vehicles with an excessively high blow-by, the valve does not meet the requirement. This is because some
of the flow will go through the hose connection to the intake collector under all conditions.
SEF244Q
INSPECTIONNJEC0023PCV (Positive Crankcase Ventilation) ValveNJEC0023S01With engine running at idle, remove PCV valve from breather sepa-
rator. A properly working valve makes a hissing noise as air passes
through it. A strong vacuum should be felt immediately when a fin-
ger is placed over the valve inlet.
ET277
Ventilation HoseNJEC0023S021. Check hoses and hose connections for leaks.
2. Disconnect all hoses and clean with compressed air. If any
hose cannot be freed of obstructions, replace.
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTIONQG
Positive Crankcase Ventilation
EC-37
h)Fuel pressure
i)Engine compression
j)EGR valve operation
k)Throttle valve
l)EVAP system
+On models equipped with air conditioner, checks should
be carried out while the air conditioner is ªOFFº.
+When checking idle speed on models equipped with A/T,
ignition timing and mixture ratio, checks should be carried
out while shift lever is in ªPº or ªNº position.
+When measuring ªCOº percentage, insert probe more
than 40 cm (15.7 in) into tail pipe.
+Turn off headlamps, heater blower, rear window defogger.
+On vehicles equipped with daytime light systems, set
lighting switch to the 1st position to light only small
lamps.
+Keep front wheels pointed straight ahead.
+If engine stops immediately after starting or idle condition
is unstable, perform the following to initialize IACV-AAC
valve:
a)Stop engine and wait 9 seconds.
b)Turn ignition ªONº and wait 1 second.
c)Turn ignition ªOFFº and wait 9 seconds.
+Make sure the cooling fan has stopped.
BASIC SERVICE PROCEDUREQG
Preparation (Cont'd)
EC-43
SEF217Z
SEF454Y
SEF455Y
Idle Air Volume LearningNJEC0562DESCRIPTIONNJEC0562S01ªIdle Air Volume Learningº is an operation to learn the idle air vol-
ume that keeps each engine within the specific range. It must be
performed under any of the following conditions:
+Each time IACV-AAC valve, throttle body or ECM is replaced.
+Idle speed or ignition timing is out of specification.
PRE-CONDITIONINGNJEC0562S02Before performing ªIdle Air Volume Learningº, make sure that all of
the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are
missed for even a moment.
+Battery voltage: More than 12.9V (At idle)
+Engine coolant temperature: 70 - 99ÉC (158 - 210ÉF)
+PNP switch: ON
+Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting
switch to the 1st position to light only small lamps.
+Cooling fan motor: Not operating
+Steering wheel: Neutral (Straight-ahead position)
+Vehicle speed: Stopped
+Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until ªFLUID
TEMP SEº in ªDATA MONITORº mode of ªA/Tº system indi-
cates less than 0.9V.
For A/T models without CONSULT-II and M/T models, drive
vehicle for 10 minutes.
OPERATION PROCEDURENJEC0562S03With CONSULT-IINJEC0562S03011. Turn ignition switch ªONº and wait at least 1 second.
2. Turn ignition switch ªOFFº and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic ªPRE-CONDITION-
INGº (previously mentioned) are in good order.
5. Turn ignition switch ªOFFº and wait at least 9 seconds.
6. Start the engine and let it idle for at least 28 seconds.
7. Select ªIDLE AIR VOL LEARNº in ªWORK SUPPORTº mode.
8. Touch ªSTARTº and wait 20 seconds.
9. Make sure that ªCMPLTº is displayed on CONSULT-II screen.
If ªINCMPº is displayed, ªIdle Air Volume Learningº will not be
carried out successfully. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Ignition timing M/T: 8±5É BTDC
A/T: 10±5É BTDC (in ªPº or ªNº position)
Without CONSULT-IINJEC0562S03021. Turn ignition switch ªONº and wait at least 1 second.
BASIC SERVICE PROCEDUREQG
Inspection Procedure (Cont'd)
EC-55
JEF091Y
2. Turn ignition switch ªOFFº and wait at least 10 seconds.
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic ªPRE-CONDITION-
INGº (previously mentioned) are in good order.
5. Turn ignition switch ªOFFº and wait at least 9 seconds.
6. Start the engine and let it idle for at least 28 seconds.
7. Disconnect throttle position sensor harness connector (brown),
then reconnect it within 5 seconds.
8. Wait 20 seconds.
9. Make sure that idle speed is within specifications. If not, the
result will be incomplete. In this case, find the cause of the
problem by referring to the NOTE below.
10. Rev up the engine two or three times. Make sure that idle
speed and ignition timing are within specifications.
ITEM SPECIFICATION
Idle speed M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Ignition timing M/T: 8±5É BTDC
A/T: 10±5É BTDC (in ªPº or ªNº position)
NOTE:
If idle air volume learning cannot be performed successfully,
proceed as follows:
1)Check that throttle valve is fully closed.
2)Check PCV valve operation.
3)Check that downstream of throttle valve is free from air
leakage.
4)Adjust closed throttle position switch and reset memory.
(Refer to Basic Inspection, EC-98.)
5)When the above three items check out OK, engine com-
ponent parts and their installation condition are question-
able. Check and eliminate the cause of the problem.
It is useful to perform ªTROUBLE DIAGNOSIS Ð SPECIFI-
CATION VALVEº, EC-140.
6)If any of the following conditions occur after the engine
has started, eliminate the cause of the problem and per-
form ªIdle air volume learningº all over again:
+Engine stalls.
+Erroneous idle.
+Blown fuses related to the IACV-AAC valve system.
BASIC SERVICE PROCEDUREQG
Idle Air Volume Learning (Cont'd)
EC-56
CONSULT-II or GST (Generic Scan Tool) Examples: P0340, P1320, P0705, P0750, etc.
These DTCs are prescribed by ISO 15031-6.
(CONSULT-II also displays the malfunctioning component or system.)
+1st trip DTC No. is the same as DTC No.
+Output of a DTC indicates a malfunction. However, Mode II and GST do not indicate whether the
malfunction is still occurring or has occurred in the past and has returned to normal.
CONSULT-II can identify malfunction status as shown below. Therefore, using CONSULT-II (if avail-
able) is recommended.
A sample of CONSULT-II display for DTC is shown below. DTC or 1st trip DTC of a malfunction is displayed
in SELF-DIAGNOSTIC RESULTS mode of CONSULT-II. Time data indicates how many times the vehicle was
driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be ª0º.
If a 1st trip DTC is stored in the ECM, the time data will be ª[1t]º.
SEF698X
Freeze Frame Data and 1st Trip Freeze Frame DataNJEC0031S0102The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant
temperature, 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 called freeze frame data and displayed on CONSULT-II or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
details, see EC-84.
Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no prior-
ity for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MI on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
Priority Items
1Freeze frame data Misfire Ð DTC: P0300 - P0304 (0300 - 0304)
Fuel Injection System Function Ð DTC: P0171 (0171), P0172 (0172)
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
For example, the EGR malfunction (Priority: 2) was detected and the freeze frame data was stored in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st trip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or
1st trip freeze frame data can be stored in the ECM). If freeze frame data is stored in the ECM memory and
freeze frame data with the same priority occurs later, the first (original) freeze frame data remains unchanged
in the ECM memory.
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM
memory is erased. Procedures for clearing the ECM memory are described in ªHow to Erase Emission-related
Diagnostic Informationº. Refer to EC-68.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
Emission-related Diagnostic Information (Cont'd)
EC-59
+The time required for each diagnosis varies with road surface conditions, weather, altitude, individual driv-
ing habits, etc.
Zone A refers to the range where the time required, for the diagnosis under normal conditions*, is the
shortest. Zone B refers to the range where the diagnosis can still be performed if the diagnosis is not
completed within zone A.
*: Normal conditions refer to the following:
þ Sea level
þ Flat road
þ Ambient air temperature: 20 - 30ÉC (68 - 86ÉF)
þ Diagnosis is performed as quickly as possible under normal conditions.
Under different conditions [For example: ambient air temperature other than 20 - 30ÉC (68 - 86ÉF)], diag-
nosis may also be performed.
Pattern 1:
+The engine is started at the engine coolant temperature of þ10 to 35ÉC (14 to 95ÉF) (where the volt-
age between the ECM terminals 70 and 58 is 3.0 - 4.3V).
+The engine must be operated at idle speed until the engine coolant temperature is greater than 70ÉC
(158ÉF) (where the voltage between the ECM terminals 70 and 58 is lower than 1.4V).
+The engine is started at the fuel tank temperature of warmer than 0ÉC (32ÉF) (where the voltage
between the ECM terminal 82 and ground is less than 4.1V).
Pattern 2:
+When steady-state driving is performed again even after it is interrupted, each diagnosis can be conducted.
In this case, the time required for diagnosis may be extended.
*1: Depress the accelerator pedal until vehicle speed is 90 km/h (56 MPH), then release the accelerator pedal
and keep it released for more than 10 seconds. Depress the accelerator pedal until vehicle speed is 90 km/h
(56 MPH) again.
*2: Checking the vehicle speed with CONSULT-II or GST is advised.
Suggested transmission gear position for A/T models
Set the selector lever in the ªDº position with ªODº ON.
Suggested upshift speeds for M/T models
Shown below are suggested vehicle speeds for shifting into a higher gear. These suggestions relate to fuel
economy and vehicle performance. Actual upshift speeds will vary according to road conditions, the weather
and individual driving habits.
Gear changeACCEL shift point
km/h (MPH)
1st to 2nd 15 (9)
2nd to 3rd 35 (22)
3rd to 4th 50 (31)
4th to 5th 70 (43)
Test Value and Test Limit (GST only Ð not applicable to CONSULT-II)NJEC0031S0104The following is the information specified in Mode 6 of ISO 15031-5.
The test value is a parameter used to determine whether a system/circuit diagnostic test is ªOKº or ªNGº while
being monitored by the ECM during self-diagnosis. The test limit is a reference value which is specified as the
maximum or minimum value and is compared with the test value being monitored.
Items for which these data (test value and test limit) are displayed are the same as SRT code items (14 test
items).
These data (test value and test limit) are specified by Test ID (TID) and Component ID (CID) and can be dis-
played on the GST screen.
X: Applicable Ð: Not applicable
SRT item Self-diagnostic test itemTest value (GST display)
Test limit Application
TID CID
CATALYST Three way catalyst function01H 01H Max. X
02H 81H Min. X
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
Emission-related Diagnostic Information (Cont'd)
EC-65
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but
all of the data listed above, are cleared from the ECM memory during work procedures.
MODELS WITHOUT EURO-OBD SYSTEMNJEC0031S07DTC and 1st Trip DTCNJEC0031S0701The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, the 1st trip
DTC will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory. If the same mal-
function 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 stored
in the ECM memory. In other words, the DTC is stored in the ECM memory when the same malfunction occurs
in two consecutive 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. For fail-safe items, the DTC is stored in the
ECM memory even in the 1st trip.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in ªHow to Erase
Emission-related Diagnostic Informationº, EC-71.
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 ªWork Flowº procedure Step II, refer to EC-96. Then perform ªDTC Confirmation Proce-
dureº or ªOverall Function Checkº to try to duplicate the problem. If the malfunction is duplicated, the item
requires repair.
How to Read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.
Without CONSULT-II
ECM displays the DTC by a set of four digit numbers with MI illumination in the diagnostic test mode II (Self-
diagnostic results). Example: 0100, 0115, 0340, 1335, etc.
With CONSULT-II
CONSULT-II displays the DTC in ªSELF-DIAG RESULTSº mode. Examples: P0100, P0115, P0340, P1335,
etc.
(CONSULT-II also displays the malfunctioning component or system.)
+1st trip DTC No. is the same as DTC No.
+Output of a DTC indicates a malfunction. However, ECM in the diagnostic test mode II (Self-diag-
nostic results) (If so equipped) does not indicate whether the malfunction is still occurring or has
occurred in the past and has returned to normal. CONSULT-II can identify malfunction status as
shown below. Therefore, the use of CONSULT-II (if available) is recommended.
A sample CONSULT-II display for DTC and 1st trip DTC is shown below. DTC or 1st trip DTC of a malfunc-
tion is displayed in the SELF-DIAGNOSTIC RESULTS mode of CONSULT-II. Time data indicates how many
times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be ª0º.
If a 1st trip DTC is stored in the ECM, the time data will be ª[1t]º.
SEF992X
Freeze Frame Data and 1st Trip Freeze Frame DataNJEC0031S0702The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant
temperature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, throttle valve opening, 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 called freeze frame data and displayed on CONSULT-II. For
details, see EC-84.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
Emission-related Diagnostic Information (Cont'd)
EC-70