Precautions When Working On ABS
lUse recommended tyres in combination with ABS.
lInstall tyres or studded tyres, etc. with the same size.
lIf different sizes of tyres, or tyres other than the ones
recommended for use with the ABS, are fitted, stopping
distance will increase and control and stability could
deteriorate.
lWhen changing brake pads, use Nissan genuine parts.
lWhen fitting radios etc, do not position the radio unit,
antenna, or antenna cables within an area of about 100
mm (3.94 in) of the control unit.
lWhen doing any work that requires electro-welding, first
remove the control unit.
lMake sure when taking a power supply for the audio,
lamps etc., not to take this from any ABS-related har-
ness. (Refer to the electrical wiring diagrams for ABS-
related harnesses)
Wiring Diagrams and Trouble Diagnosis
When you read wiring diagrams, refer to the following:
lGI-11, ªHOW TO READ WIRING DIAGRAMSº
lEL-10, ªPOWER SUPPLY ROUTINGº
When you perform trouble diagnosis, refer to the following:
lGI-35, ªHOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSISº
lGI-24, ªHOW TO PERFORM EFFICIENT DIAGNOSES FOR AN ELECTRICAL INCIDENTº
PRECAUTIONS
BR-4
Engine Fuel & Emission Control System
NEF390 ECM (ECCS-D control module)
lDo not disassemble ECM.lIf a battery terminal is disconnected, the memory
will return to the ECM value.
The ECM will now start to self-control at its initial
value. Engine operation can vary slightly when
the terminal is disconnected. However, this is not
an indication of a problem. Do not replace parts
because of a slight variation.
lWhen ECM is removed for inspection, make sure
to ground the ECM mainframe.WIRELESS EQUIPMENT
lWhen installing C.B. ham radio or a mobile
phone, be sure to observe the following as it
may adversely affect electronic control sys-
tems depending on its installation location.
1) Keep the antenna as far as possible away
from the ECM.
2) Keep the antenna feeder line more than
20 cm (7.9 in) away from the harness of elec-
tronic controls.
Do not let them run parallel for a long dis-
tance.
3) Adjust the antenna and feeder line so that the
standing-wave ratio can be kept small.
4) Be sure to ground the radio to vehicle body.
ECM HARNESS HANDLING
lConnect ECM harness connectors securely.
A poor connection can cause an extremely
high (surge) voltage to develop in coil and
condenser, thus resulting in damage to ICs.
lKeep ECM harness at least 10 cm (3.9 in)
away from adjacent harnesses, to prevent an
ECM system malfunction due to receiving
external noise, degraded operation of ICs,
etc.
lKeep ECM parts and harnesses dry.lBefore removing parts, turn off ignition
switch and then disconnect battery ground
cable. WHEN STARTING
lDo not depress accelerator pedal when
starting.
lImmediately after starting, do not rev up
engine unnecessarily.
lDo not rev up engine just prior to shut-
down. ECM PARTS HANDLING
lHandle mass air flow sensor carefully to avoid
damage.
lDo not disassemble mass air flow sensor.lDo not clean mass air flow sensor with any type
of detergent.
lDo not disassemble No. 1 injection nozzle (built-
in needle lift sensor).
lEven a slight leak in the air intake system can
cause serious problems.
lDo not shock or jar the camshaft position sensor
(TDC). ELECTRONIC FUEL INJECTOR PUMP
lDo not disconnect pump harness connectors
with engine running.
lDo not disassemble or adjust electronic fuel
injection pump, except for the following
parts.
Camshaft position sensor (pump)
Injection timing control valve
Fuel cut solenoid valve BATTERY
lAlways use a 12 volt battery as power
source.
lDo not attempt to disconnect battery cables
while engine is running.
ECM mainframe
PRECAUTIONS AND PREPARATIONCD20T
EC-5
Anti-theft System
NATS Audio Link
Description
The link with the NATS IMMU implies that the audio unit can basically only be operated if connected to the
matching NATS IMMU to which the audio unit was initially fitted on the production line.
Since radio operation is impossible after the link with the NATS is disrupted theft of the audio unit is basi-
cally useless since special equipment is required to reset the audio unit.
Initialization process for audio units that are linked to the NATS IMMU
New audio units will be delivered to the factories in the“NEW”state, i.e. ready to be linked with the vehi-
cle’s NATS. When the audio unit in“NEW”state is first switched on at the factory, it will start up communi-
cation with the vehicle’s immobiliser control unit (IMMU) and send a code (the“audio unit Code”)tothe
IMMU. The IMMU will then store this code, which is unique to each audio unit, in its (permanent) memory.
Upon receipt of the code by the IMMU, the NATS will confirm correct receipt of the audio unit code to the
audio unit. Hereafter, the audio unit will operate as normal.
During the initialisation process,“NEW”is displayed on the audio unit display. Normally though, communi-
cation between audio unit and IMMU takes such a short time (300 ms) that the audio unit seems to switch
on directly without showing“NEW”on its display.
Normal operation
Each time the audio unit is switched on afterwards, the audio unit code will be verified between the audio
unit and the NATS before the audio unit becomes operational. During the code verification process,“WAIT”
is shown on the audio unit display. Again, the communication takes such a short time (300 ms) that the audio
unit seems to switch on directly without showing“WAIT”on its display.
When the radio is locked
In case of a audio unit being linked with the vehicle’s NATS (immobilizer system), disconnection of the link
between the audio unit and the IMMU will cause the audio unit to switch into the lock (“SECURE”) mode in
which the audio unit is fully inoperative. Hence, repair of the audio unit is basically impossible, unless the
audio unit is reset to the“NEW”state for which special decoding equipment is required.
The radio manufacturer has provided their authorized service representatives with so called“decoder boxes”
which can bring the audio unit back to the“NEW”state, enabling the audio unit to be switched on after which
repair can be carried out. Subsequently, when the repaired audio unit is delivered to the final user again, it
will be in the“NEW”state as to enable re-linking the audio unit to the vehicle’s immobiliser system. As a
result of the above, repair of the audio unit can only be done by an authorized representative of the radio
manufacturer.
Service instruction
Item Radio linked with IMMU and/or SECU
Battery disconnection No additional action required
Radio needs repair Repair needs to be done by authorised representative of radio manufacturer since radio cannot
be operated unless it is reset to NEW state, using special decoding equipment
Replacement of radio by new part Radio is delivered in NEW state. If possible, the radio will automatically link up with the immobil-
iser system. If this appears not possible, the audio unit code needs to be manually input
Transferring radio to another
vehicle / replacement of radio by
an‘‘old’’partRadio needs to be reset to NEW state by authorised representative of radio manufacturer
Replacement of IMMU by new part Radio will request for the audio unit code input prior to establishing the link with the IMMU
Replacement of IMMU by old part If a radio code has already been stored in memory of the IMMU, the radio cannot be linked to it.
After switching on the radio, it will display‘‘SECURE’’after 1 minute. Operation can only be
established after resetting the ratio by an authorised representative of radio manufacturer
No communication from IMMU to radio Radio will display‘‘SECURE’’after 180 attempts to communicate with IMMU. Further use of radio
impossible until communication is established again, or after radio is reset by authorised repre-
sentative of (radio) manufacturer
AUDIO
EL-216