
SAE J1930 Terminology List
All emission related terms used in this publication in accordance with SAE J1930 are listed. Accordingly, new
terms, new acronyms/abbreviations and old terms are listed in the following chart.
***: Not applicable
NEW TERMNEW ACRONYM /
ABBREVIATIONOLD TERM
Air cleaner ACL Air cleaner
Barometric pressure BARO ***
Barometric pressure sensor-BCDD BAROS-BCDD BCDD
Camshaft position CMP ***
Camshaft position sensor CMPS Crank angle sensor
Canister *** Canister
Carburetor CARB Carburetor
Charge air cooler CAC Intercooler
Closed loop CL Closed loop
Closed throttle position switch CTP switch Idle switch
Clutch pedal position switch CPP switch Clutch switch
Continuous fuel injection system CFI system ***
Continuous trap oxidizer system CTOX system ***
Crankshaft position CKP ***
Crankshaft position sensor CKPS ***
Data link connector DLC ***
Data link connector for CONSULT DLC for CONSULT Diagnostic connector for CONSULT
Diagnostic test mode DTM Diagnostic mode
Diagnostic test mode selector DTM selector Diagnostic mode selector
Diagnostic test mode I DTM I Mode I
Diagnostic test mode II DTM II Mode II
Diagnostic trouble code DTC Malfunction code
Direct fuel injection system DFI system ***
Distributor ignition system DI system Ignition timing control
Early fuel evaporation-mixture heater EFE-mixture heater Mixture heater
Early fuel evaporation system EFE system Mixture heater control
Electrically erasable programmable read only
memoryEEPROM ***
Electronic ignition system EI system Ignition timing control
Engine control EC ***
Engine control module ECM ECCS control unit
Engine coolant temperature ECT Engine temperature
Engine coolant temperature sensor ECTS Engine temperature sensor
Engine modi®cation EM ***
Engine speed RPM Engine speed
Erasable programmable read only memory EPROM ***
Evaporative emission canister EVAP canister Canister
SAE J1930 TERMINOLOGY LIST
GI-43 

***: Not applicable
NEW TERMNEW ACRONYM /
ABBREVIATIONOLD TERM
Evaporative emission system EVAP system Evaporative emission control system
Exhaust gas recirculation valve EGR valve EGR valve
Exhaust gas recirculation control-BPT valve EGRC-BPT valve BPT valve
Exhaust gas recirculation control-solenoid valve EGRC-solenoid valve EGR control solenoid valve
Exhaust gas recirculation temperature sensor
EGRT sensor Exhaust gas temperature sensor
EGR temperature sensor
Flash electrically erasable programmable read
only memoryFEEPROM ***
Flash erasable programmable read only memory FEPROM ***
Flexible fuel sensor FFS ***
Flexible fuel system FF system ***
Fuel pressure regulator *** Pressure regulator
Fuel pressure regulator control solenoid valve *** PRVR control solenoid valve
Fuel trim FT ***
Heated Oxygen sensor HO2S Exhaust gas sensor
Idle air control system IAC system Idle speed control
Idle air control valve-air regulator IACV-air regulator Air regulator
Idle air control valve-auxiliary air control valve IACV-AAC valve Auxiliary air control (AAC) valve
Idle air control valve-FICD solenoid valve IACV-FICD solenoid valve FICD solenoid valve
Idle air control valve-idle up control solenoid
valveIACV-idle up control solenoid
valveIdle up control solenoid valve
Idle speed control-FI pot ISC-FI pot FI pot
Idle speed control system ISC system ***
Ignition control IC ***
Ignition control module ICM ***
Indirect fuel injection system IFI system ***
Intake air IA Air
Intake air temperature sensor IAT sensor Air temperature sensor
Knock *** Detonation
Knock sensor KS Detonation sensor
Malfunction indicator lamp MIL Check engine light
Manifold absolute pressure MAP ***
Manifold absolute pressure sensor MAPS ***
Manifold differential pressure MDP ***
Manifold differential pressure sensor MDPS ***
SAE J1930 TERMINOLOGY LIST
SAE J1930 Terminology List (Cont'd)
GI-44 

System Description
SWITCH AND THEIR CONTROL FUNCTIONS
Knob/SwitchKnob/Switch position
Air outlet Intake air Compressor
A/C
A/CjÐ Ð ON*
Mode
jVENT Ð Ð
jB/L Ð Ð
jFOOT Ð Ð
jD/F FRE Ð
jDEF FRE ON*
jÐÐÐ
*: Compressor is operated by dual-pressure switch.
Control Operation
FAN CONTROL KNOB
This knob turns the fan ON and OFF, and controls fan speed.
MODE CONTROL KNOB
This knob controls the outlet air ¯ow.
TEMPERATURE CONTROL KNOB
This knob allows adjustment of the temperature of the outlet air.
RECIRCULATION (REC) SWITCH
OFF position: Outside air is drawn into the passenger compartment.
ON position: Interior air is recirculated inside the vehicle. The indicator lamp will also light.
AIR CONDITIONER SWITCH
The air conditioner switch controls the A/C system. When the switch is depressed with the fan ON, the com-
pressor will turn ON. The indicator lamp will also light.
The air conditioner cooling function operates only when the engine is running.
RHA582G
DESCRIPTIONMANUAL
HA-16 

Operational Check
The purpose of the operational check is to con®rm that the system
operates properly.
CONDITIONS
Engine running at normal operating temperature.
PROCEDURE
1. Check blower
a. Turn fan control knob to 1-speed.
Blower should operate on 1-speed.
b. Then turn fan control knob to 2-speed.
c. Continue checking blower speed until all four speeds are
checked.
d. Leave blower on 4-speed.
2. Check discharge air
a. Turn mode control knob.
b. Con®rm that discharge air comes out according to the air dis-
tribution table at left.
Refer to ``Discharge Air Flow'' in ``DESCRIPTION'' (HA-13).
RHA583G
RHA584G
RHA654F
TROUBLE DIAGNOSESMANUAL
HA-22 

Air mix door control (Automatic temperature control)
The air mix door is automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by: The temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.
Fan speed control
Blower speed is automatically controlled based on temperature setting, ambient temperature, in-vehicle
temperature, intake temperature, amount of sunload and air mix door position.
With FAN switch set to ``AUTO'', the blower motor starts to gradually increase air ¯ow volume.
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from ¯ow-
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
temperature, intake temperature and amount of sunload.
Magnet clutch control
The ECM (ECCS control module) controls compressor operation using input signals from the throttle position
sensor and auto ampli®er.
Self-diagnostic system
The self-diagnostic system is built into the auto ampli®er (LCU) to quickly locate the cause of problems.
RHA442G
DESCRIPTIONAUTO
Features (Cont'd)
HA-51 

Self-diagnosis
INTRODUCTION AND GENERAL DESCRIPTION
The self-diagnostic system diagnoses sensors, door motors,
blower motor, etc. by system line. Refer to applicable sections
(items) for details. Shifting from normal control to the self-diagnos-
tic system is accomplished by starting the engine (turning the igni-
tion switch from ``OFF'' to ``ON'') and pressing ``
'' switch for at
least 5 seconds. The ``
'' switch must be pressed within 5 sec-
onds after starting the engine (ignition switch is turned ``ON''). This
system will be canceled by either pressing
(AUTO) switch or
turning the ignition switch ``OFF''. Shifting from one step to another
is accomplished by means of turning temperature dial clockwise or
counterclockwise, as required.
Additionally shifting from STEP 4 to AUXILIARY MECHANISM is
accomplished by means of pushing
(fan) switch.
(Ignition switch OFF®ON)
Within 5 seconds after starting engine (ignition
switch is turned ``ON''), press
switch for
at least 5 seconds.
STEP 1 Ð LEDs and LCD are checked.
m
Left turnRight turn
STEP 2 Ð Input signals from each sensor are
checked.
m
Left turnRight turn
STEP 3 Ð Mode and intake door motor posi-
tion switch is checked.Ignition switch: OFFc
or(AUTO) switch: ONSelf-diagnostic function is canceled.m
Left turnRight turn
Note
STEP 4 Ð Actuators are checked.
m
AUXILIARY MECHANISM Ð Temperature set-
ting trimmerNote:
For STEP 4, engine must be running for
compressor to operate.
.
.
.
.
.
.
TROUBLE DIAGNOSESAUTO
HA-63 

SYSTEM DESCRIPTION
Component parts
Fan speed control system components are:
1) Auto amp.
2) Fan control amp.
3) A/C LAN system (PBR built in mode door motor and air mix door motor)
4) In-vehicle sensor
5) Ambient sensor
6) Sunload sensor
7) Intake sensor
System operation
Automatic mode
In the automatic mode, the blower motor speed is calculated by the automatic ampli®er based on inputs from
the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor. The blower motor applied
voltage ranges from approximately 5 volts (lowest speed) to 12 volts (highest speed).
The control blower speed (in the range of 5 to 12V), the automatic ampli®er supplies a gate voltage to the fan
control ampli®er. Based on this voltage, the fan control ampli®er 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 50ÉC, 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 55ÉC,
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 AUTO button is pushed. The blower speed will gradu-
ally rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
SHA006FB
TROUBLE DIAGNOSESAUTO
Blower Motor (Cont'd)
HA-87 

Maintenance of Lubricant Quantity in
Compressor
The lubricant used to lubricate the compressor circulates through
the system with the refrigerant. Add lubricant to compressor when
replacing any component or after a large gas leakage occurred. It
is important to maintain the speci®ed amount.
If lubricant quantity is not maintained properly, the following mal-
functions may result:
+Lack of lubricant: May lead to a seized compressor
+Excessive lubricant: Inadequate cooling (thermal exchange
interference)
LUBRICANT
Name: Nissan A/C System Oil Type S
Part number: KLH00-PAGS0
CHECKING AND ADJUSTING
Adjust the lubricant quantity according to the ¯owchart shown
below.
START
Can lubricant return operation be per-
formed?
+A/C system works properly.
+There is no evidence of a large amount of
lubricant leakage.
No
cYe s
Perform lubricant return operation, proceeding as follows:
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1. Start engine, and set the following conditions:
+Test condition
Engine speed: Idling to 1,200 rpm
A/C or AUTO switch: ON
Blower speed: Max. position
Temp. control: Optional [Set so that intake air temperature is
25 to 30ÉC (77 to 86ÉF).]
2. Perform lubricant return operation for about 10 minutes.
3. Stop engine.
CAUTION:
If excessive lubricant leakage is noted, do not perform the lubricant
return operation.
Should the compressor be replaced?
No Yes
b
jA(Go to next page.)
Is there any part to be replaced?
(Evaporator, condenser, liquid tank or in
case there is evidence of a large amount of
lubricant leakage.)
No
cYe s
After replacing any of the following major components, add the correct
amount of lubricant to the system.
Amount of lubricant to be added
*1: If compressor is replaced, addition of lubricant is included in the ¯ow
chart.
*2: If refrigerant leak is small, no addition of lubricant is needed.
Carry out the A/C performance test.b
Part replacedLubricant to be added to sys-
tem
Remarks
Amount of lubricant
m!(Imp ¯ oz)
Evaporator 75 (2.6) Ð
Condenser 75 (2.6) Ð
Liquid tank 5 (0.2)Add if compressor is not
replaced. *1
In case of refrigerant leak30 (1.1) Large leak
Ð Small leak*2
.
.
.
.
.
SERVICE PROCEDURESMANUAL AND AUTO
HA-114