Nissan PULSAR N13 Series / ASTRA LD Series. Manual — part 22

Fuel and Engine Management

89

The procedure for fabricating an LED test lamp is

fully described in the Electrical System section.

If a conventional test lamp with a filament type

bulb is to be used, ensure that the current draw of the
test lamp does not exceed 0.3 amp to avoid damage to
the electronic components.

To check the current draw connect an accurate

ammeter, such as the multimeter described previ-
ously, in series with the test lamp and a battery.

If the ammeter reads less than 0.3 amp the test

lamp is suitable.

Tachometer

(1) Disconnect the resistor from the tachometer

pick-up wiring connector which is located on the
ignition coil wiring harness, and connect the positive
lead of an accurate tachometer to the brown wire
terminal in the wiring connector.

(2) Connect the negative lead to a good earthing

point.

View showing the location of the tachometer pickup

wiring connector with the resistor installed.

Timing Light

(1) Connect the timing light to the engine fol-

lowing the instrument manufacturers instructions.

NOTE: Do not connect or disconnect the
timing light with the engine running as
voltage surges could damage the alternator
or control unit. Do not allow the high
tension leads to open circuit with the engine
running as damage to the engine manage-
ment system could result.

(2) Do not connect the timing light positive lead

to the alternator output terminal. Where possible,
connect the power leads of the timing light to an
external power source to prevent possible transient
voltages damaging the alternator or control unit.

4. SYSTEM DIAGNOSIS AND ADJUSTMENTS

NOTE: Due to the use of complex electronic
components in the engine management sys-

tem, the diagnosis and testing procedures
described in this section should not be
carried out by persons lacking an under-
standing of electronics and the precautions
associated with the servicing of electronic
components. It is recommended that should
a fault arise in the system, the vehicle be
referred to an authorized workshop.

The control unit can be damaged by

component faults not indicated by the self
diagnosis codes and the renewal of the
control unit without locating the cause of
the failure will result in the failure of the
replacement unit. It is for this reason that
the practice of substituting components to
isolate faults is not recommended.

Prior to performing any of the follow-

ing operations, refer to the Service Pre-
cautions and Procedures heading.

PRELIMINARY CHECKS

Prior to performing the Self Diagnosis Test Pro-

cedures, perform the following preliminary checks and
rectify any problems as necessary.

(1) Check for an adequate supply of fuel in the

fuel tank.

(2) Check the wiring connectors and earth points

of all engine management components for clean,
secure connections. To prevent damage to the control
unit, disconnect the negative battery terminal before
disconnecting any engine management wiring connec-
tors.

(3) Check the condition of the battery. Refer to

the Electrical System section for checking procedures.
Rectify any faults as necessary.

(4) Check the air cleaner element for restriction.
(5) Check for air leaks at the throttle body, inlet

manifold and all related hoses.

(6) Check the fuel pump pressure as described

later in this section.

(7) Ensure that the engine is in a satisfactory

mechanical condition and is in tune. Refer to the
Engine and Engine Tune-up sections as necessary.

SELF DIAGNOSIS

This function is very useful in locating system

faults particularly intermittent problems. However,
the self diagnosis mode does not provide comprehen-
sive testing of the engine management system, and
therefore should always be used in conjunction with
the other test procedures described later, in order to
accurately locate system faults.

To Interpret Self Diagnosis Codes

Once the self diagnosis mode is activated, various

fault codes will be displayed as a series of flashes by
the ECM warning lamp on the instrument cluster.

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Fuel and Engine Management

To identify the code number, count the number of

times the ECM warning lamp flashes. Each fault code
comprises two groups of flashes separated by a 1.2
second pause. The first group represents tens and the
second group represents single units. For example 1
flash followed by a 1.2 second pause followed by 4
flashes would be code number 14. Similarly 4 flashes
followed by a 1.2 second pause followed by 2 flashes
would be code number 42.

The code will be displayed three times. If more

than one fault code is present, the self diagnosis
system will indicate each one in numerical order, with
a 3.2 second pause between each code, and then
repeat the sequence.

The fault codes can be identified as follows:

CODE NUMBER

FAULT AREA

12

Satisfactory operation

13

Oxygen sensor open circuit

14

Coolant temperature sensor

circuit (voltage low)

15

Coolant temperature sensor

circuit (voltage high)

21

Throttle position sensor circuit

(voltage high)

22

Throttle position sensor circuit

(voltage low)

23

MAT sensor circuit

(voltage' high) 1.8 liter engine

only

24

Vehicle speed sensor circuit

25

MAT sensor circuit

(voltage low) 1.8 liter engine

only

33

MAP sensor circuit

(voltage high)

34

MAP sensor circuit

(voltage low)

42

Electronic spark timing circuit

44

Oxygen sensor circuit

(lean exhaust)

45

Oxygen sensor circuit

(rich exhaust)

51

Mem-Cal

55

Control unit input circuits

Test Procedure

(1) Perform the following checks:

(a) Ensure that the battery voltage is above 11

volts.

(b) Ensure that the throttle valve is fully closed.
(c) Place the transaxle in neutral.
(d) Ensure that the air conditioner, fan, tights

and all other accessories are switched off.

(2) Turn the ignition On and confirm that the

ECM warning lamp on the instrument cluster is
illuminated but not flashing.

If code 55 is displayed, refer to the Control Unit

heading, perform the circuit test procedure and rectify
the cause of the code before proceeding.

If the ECM warning lamp flashes codes other than

code 55, check the wiring harness between the diag-
nostic link connector terminal B and the control unit
wiring connector terminal A9 for shorts. Repair or
renew the wiring harness as necessary.

If no fault can be found, renew the control unit.

If the ECM warning lamp does not illuminate,

proceed as follows:

(a) Check the METER fuse located in the fuse

panel adjacent to the steering column and the fusible
links located in the fusible link connecting block at the
rear of the battery. Renew the fuse or fusible links as
necessary.

(b) Check the wiring harness to the instrument

cluster. Repair or renew the harness.

(c) Check the Check Engine lamp bulb. Renew if

necessary.

(d) Check the EGI relay. Renew as necessary.

(3) Connect a jumper lead across terminals A

and B on the diagnostic link connector located under
the front passengers seat above the control unit.

(4) Note the codes indicated by the flashing

ECM warning lamp.

If code 12 is displayed, the system is operating

correctly.

If codes other than code 12 are displayed, refer to

the component or circuit test procedure under the
appropriate heading as indicated by the code number.

If more than one code is being displayed, test each

indicated fault working in the order of display of the
code numbers.

(5) After completing the self diagnosis test pro-

cedure, remove the jumper lead from the diagnostic
link connector.

(6) After repairing or renewing the necessary

View showing the location of the diagnostic link

connector. Passengers seat removed for clarity.

Inset shows the diagnostic link connector terminal

identification.

Fuel and Engine Management

91

components, erase the self diagnosis memory as
described under the following heading.

(7) Repeat the self diagnosis test procedure and

ensure that code 12 is displayed.

To Erase Memory

(1) With the ignition Off, remove the fusible link

that is positioned third from the front of the fusible
link connecting block located at the rear of the
battery.

(2) Install the fusible link after 10 seconds.

View showing the location of the fusible links.

TO CHECK AND ADJUST IGNITION TIMING

(1) Connect a timing light to the engine as

previously described under the Service Precautions
and Procedures heading.

(2) Start the engine and allow it to reach normal

operating temperature.

(3) Connect a jumper lead between terminals A

and B on the diagnostic link connector.

(4) With the engine idling at the specified speed,

check the ignition timing with the timing light.

The timing mark on the crankshaft pulley should

be aligned with the pointer on the inner liming belt
cover.

(5) If necessary, loosen the distributor body

retaining nuts and turn the distributor until the timing
marks are aligned.

(6) Tighten the distributor body retaining nuts

and check that the timing is correct.

(7) Remove the jumper lead from the diagnostic

link connector and disconnect the timing light from
the engine.

TO ADJUST BASE IDLE SPEED

NOTE: The idle speed is controlled by the
idle air control (IAC) valve and is not

adjustable. The throttle stop screw controls
the base idle speed and is factory set. The
following base idle speed adjustment should
only be performed if the throttle body has
been renewed, or if comprehensive testing of
related components indicates that adjust-
ment is required.

(1) Before adjusting the base idle speed perform

the following tests;

(a) Check the spark plug gaps, the high tension

leads and the ignition timing as described previously
in the Engine Tune-up section.

(b) Check the air inlet system for leaks between

the throttle body and inlet manifold and the inlet
manifold and cylinder head.

NOTE; Any vacuum leaks will make the
engine idle faster than it should.

(c) Check that all wiring connectors and vacuum

hoses are securely connected.

(d) Ensure that the transaxle is in Park or

Neutral.

(e) Ensure that the air cleaner element is service-

able.

(2) On 1.6 liter engines, remove the air cleaner

assembly, disconnect the vacuum hose from the
throttle body and seal the vacuum hose fitting.

(3) Ensure that the throttle valve moves freely

and returns to the fully closed position when slowly
released.

(4) Connect an accurate tachometer to the en-

gine as previously described under the Service Pre-
cautions and Procedures heading.

(5) Start the engine and allow the engine to

warm up and the idle rpm to stabilize. Check that all
electrical accessories and the air conditioning, if
equipped, are turned off.

(6) With the engine idling in Park or Neutral,

slowly disconnect the brake servo unit vacuum supply
hose from the inlet manifold. Allow the engine to run
for one minute.

Location of the base idle adjusting screw. 1.8 liter

engine.

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Fuel and Engine Management

Installed view of the throttle body assembly showing

the location of the base idle adjusting screw. 1.6 liter

engine.

(7) Disconnect the IAC valve wiring connector

and slowly connect the vacuum supply hose to the
inlet manifold. Allow five seconds to elapse and note
the engine speed.

(8) If the engine speed is not to Specifications,

remove the plug from the throttle body housing on 1.6
liter engines, or the cap from the base idle adjusting
screw on 1.8 liter engines, and adjust the idle screw
until the engine speed is 625 rpm.

(9) Stop the engine and connect the IAC valve

wiring connector.

(10) On 1.8 liter engines, install a new cap to

the
base idle adjusting screw.

On 1.6 liter engines, seal the throttle stop screw

with silicone sealant and install the air cleaner assem-
bly.

(11) Erase the memory codes as previously de-

scribed.

(12) Start the engine and increase the speed to

3 000 rpm for 10 seconds to allow the idle air control
valve to reset.

5. FUEL SUPPLY COMPONENTS

Special Equipment Required:

To Check Fuel Pressure — 0-500 kPa pressure
gauge

NOTE: Before proceeding with any of the
operations in this section, refer to the Ser-
vice Precautions and Procedures heading.

TO DEPRESSURISE FUEL SYSTEM

(1) Lift the front edge of the rear seat cushion on

each side, slide the cushion forward and remove it
from the vehicle.

(2) Disconnect the fuel pump wiring harness

connector.

When depressurizing the fuel system, remove the rear

seat cushion and disconnect the fuel pump wiring

connector.

(3) Start and run the engine until it stalls.

Operate the starter motor for 10 seconds to ensure
that the pressure has dissipated.

(4) Connect the fuel pump wiring connector and

install the rear seat cushion.

NOTE: Failure to depressurize the fuel sys-
tem when instructed may result in a fuel
spray and possible fire.

TO TEST FOR EXTERNAL LEAKS

(1) Connect a jumper lead between terminals G

and H on the diagnostic link connector.

(2) Switch the ignition On.
(3) Check for leaks at all hose connections and

joints between the fuel pump and the engine.

(4) Switch the ignition Off and remove the

jumper lead from the diagnostic link connector.

(5) If renewal of a component is necessary,

depressurize the fuel system as previously described.

(6) Use only hoses and clamps as specified by

the manufacturer.

TO CHECK FUEL PRESSURE

(1) Depressurize the fuel system as previously

described.

(2) On 1.6 liter engines, remove the air cleaner

as described in this section under the Air Cleaner
Assembly heading.

(3) On 1.8 liter engines, release the hose clamp

securing the fuel supply hose to the fuel rail and
disconnect the hose.

On 1.6 liter engines, release the hose clamp

securing the fuel supply hose to the rear throttle body
hose fitting and disconnect the hose.

(4) Using a suitable gauge, tee piece, short piece

of fuel hose and clamps, install the pressure
gauge
between the fuel supply hose and the fuel rail on 1.8