AT-38
[EURO-OBD]
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
A sample of CONSULT-II display for DTC is shown in the following
page. DTC or 1st trip DTC of a malfunction is displayed in SELF
DIAGNOSIS mode for “ENGINE” with CONSULT-II. Time data indi-
cates 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 “0”.
If a 1st trip DTC is stored in the ECM, the time data will be “1t”.
Freeze Frame Data and 1st Trip Freeze Frame Data
The ECM has a memory function, which stores the driving condition such as fuel system status, calculated
load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and 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
detail, refer to " ", “CONSULT-II”.
Only one set of freeze frame data (either 1st trip freeze frame data of 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 priority
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/MIL 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 following priorities to update the data.
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM mem-
oryiserased.
SAT014K
SAT015K
SAT016K
Priority Items
1 Freeze frame data Misfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
CAN COMMUNICATION
AT-129
[EURO-OBD]
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CAN COMMUNICATIONPFP:23710
System DescriptionECS004VP
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
FOR A/T MODELS
System diagram
Input/output signal chart
T: Transmit R: Receive
SKIA0884E
Signals ECM TCM
Engine speed signal T R
Engine coolant temperature signal T R
Accelerator pedal position signal T R
A/T self-diagnosis signal R T
CAN COMMUNICATION
AT-351
[EXC.F/EURO-OBD]
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CAN COMMUNICATIONPFP:23710
System DescriptionECS004VQ
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
FOR A/T MODELS
System diagram
Input/output signal chart
T: Transmit R: Receive
SKIA0884E
Signals ECM TCM
Engine speed signal T R
Engine coolant temperature signal T R
Accelerator pedal position signal T R
A/T self-diagnosis signal R T
ATC-26
AIR CONDITIONER CONTROL
FAN SPEED CONTROL
Blower speed is automatically controlled based on temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and air mix door position.
With FAN switch set to AUTO, the blower motor starts to gradually increase air flow volume.
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake doors are automatically controlled by: The temperature setting, ambient temperature, in-vehicle
temperature, intake temperature, amount of sunload and ON-OFF operation of the compressor.
OUTLET DOOR CONTROL
The outlet door is automatically controlled by: The temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature and amount of sunload.
MAGNET CLUTCH CONTROL
The ECM controls compressor operation using input signals from the throttle position sensor and auto ampli-
fier.
SELF-DIAGNOSTIC SYSTEM
The self-diagnostic system is built into the auto amplifier (LCU) to quickly locate the cause of problems.
Overview of Control systemEJS000TK
The control system consists of input sensors, switches, the automatic amplifier (microcomputer) and outputs.
The relationship of these components is shown in the diagram below:
RJIA0481E
TROUBLE DIAGNOSIS
ATC-69
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SYSTEM DESCRIPTION
Component Parts
Fan speed control system components are:
lAuto amp.
lA/C LAN system (PBR built-in air mix door motor, mode door motor and intake door motor)
lFan control amp.
lIn-vehicle sensor
lAmbient sensor
lSunload sensor
lIntake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calculated by the automatic amplifier based on input from
the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor.
The blower motor applied voltage ranges from approximately 4 volts (lowest speed) to 12 volts (highest
speed).
The control blower speed (in the range of 4 to 12V), the automatic amplifier supplies a gate voltage to the fan
control amplifier. Based on this voltage, the fan control amplifier controls the voltage supplied to the blower
motor.
Starting Fan Speed Control
Start Up From COLD SOAK Condition (Automatic mode)
In a cold start up condition where the engine coolant temperature is below 56°C (133°F), the blower will not
operate for a short period of time (up to 150 seconds). The exact start delay time varies depending on the
ambient and engine coolant temperature.
In the most extreme case (very low ambient) the blower starting delay will be 150 seconds as described
above. After this delay, the blower will operate at low speed until the engine coolant temperature rises above
56°C (133°F), at which time the blower speed will increase to the objective speed.
Start Up From Normal or HOT SOAK Condition (Automatic mode)
The blower will begin operation momentarily after the A/C button is pushed. The blower speed will gradually
rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
Blower Speed Compensation
Sunload
SHA006FD
CO-10
[QR20DE]
ENGINE COOLANT
2. Open drain plugs on cylinder block.
3. Remove reservoir tank and drain coolant.
4. Check drained coolant for contaminants such as rust, corrosion
or discoloration.
If contaminated, flush engine cooling system. Refer toCO-10,
"FLUSHING COOLING SYSTEM".
REFILLING ENGINE COOLANT
1. Install reservoir tank, radiator drain plug and cylinder block drain plug.
Apply sealant to the thread of cylinder block drain plug.
lUse Genuine Liquid Gasket or equivalent.
2. Fill radiator and reservoir tank to specified level.
lUse genuine Nissan anti-freeze coolant or equivalent mixed
with water (distilled or demineralized).
Refer toMA-17, "
RECOMMENDED FLUIDS AND LUBRI-
CANTS".
lPour coolant slowly of less than 2 (2-1/8US qt,1-3/4 lmp
qt) a minute to allow air in system to escape.
3. Warm up engine to normal operating temperature without radia-
tor cap installed.
lIf coolant overflows radiator filler hole, install filler cap.
4. Run engine at 3,000 rpm for 10 seconds and return to idle speed
with radiator cap installed.
lRepeat two or three times.
Watch coolant temperature gauge so as not to overheat the engine.
5. Stop engine and cool down to less than approximately 50°C(122°F).
lCool down using a fan to reduce the time.
lIf necessary, refill radiator up to filler neck with coolant.
6. Refill reservoir tank to MAX level line with coolant.
7. Repeat steps 5 through 7 two or more times with radiator cap installed until coolant level no longer drops.
8. Check cooling system for leaks with engine running.
9. Warm up engine, and check for sound of coolant flow while running engine from idle up to 3,000 rpm with
heater temperature controller set at several position between COOL and WARM.
lSound may be noticeable at heater unit.
10. If sound is heard, bleed air from cooling system by repeating steps 5 through 7 until coolant level no
longer drops.
lClean excess coolant from engine.
FLUSHING COOLING SYSTEM
1. Fill radiator and reservoir tank with water and reinstall radiator cap.
KBIA0163E
: 7.8 - 11.8 N·m (0.8 -1.2 kg-m , 69 - 104 in-lb)
Engine coolant capacity (With reservoir tank):
Approx. 7.1 (6-1/4 Imp qt)
SMA182B
Reservoir tank:
0.6 (1/2 lmp qt )
SMA412B
ENGINE COOLANT
CO-11
[QR20DE]
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2. Run engine and warm it up to normal operating temperature.
3. Rev engine two or three times under no-load.
4. Stop engine and wait until it cools down.
5. Drain water.
6. Repeat steps 1 through 5 until clear water begins to drain from radiator.
THERMOSTAT AND WATER CONTROL VALVE
CO-21
[QR20DE]
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THERMOSTAT AND WATER CONTROL VALVEPFP:21200
Removal and InstallationEBS009SK
WA RN ING:
Never remove the radiator cap when the engine is hot. Serious burns could occur from high pressure
coolant escaping from the radiator.
REMOVAL
Thermostat Removal
1. Drain engine coolant. Refer toCO-9, "DRAINING ENGINE COOLANT".
CAUTION:
Perform when the engine cold.
2. Disconnect radiator lower hose at water inlet side.
3. Remove water inlet and thermostat.
Water Control Valve Removal
1. Drain engine coolant. Refer toCO-9, "DRAINING ENGINE COOLANT".
2. Disconnect upper radiator hose, heater pipe and heater hose at water outlet side.
3. Remove water outlet.
4. Remove water control valve.
PBIC0239E
1 Thermostat 2 Water inlet 3 Water control valve
4 Water outlet 5 Heater hose 6 Engine coolant temperature sensor
7Heaterpipe