1987 NISSAN PULSAR lights

110 Fuel and Engine Management
originally performed, an intermittent fault is indi-
cated. Proceed as follows:

(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Disconnect the wiring connector from the
coolant temperature sensor. (5) With the ignition switched On, measure the
voltage across the terminals on the coolant tempera-
ture sensor wiring connector. The voltage should be
4-6 volts.
If the voltage is below 4 volts, proceed to opera-
tion (9).

If the voltage is as specified, proceed as follows.
(6) Remove the coolant temperature sensor
from the vehicle. (7) Connect an ohmmeter to the coolant temper-
ature sensor terminals. (8) Immerse the meta1 end of the coolant
tem-
perature sensor in a 50/50 mixture of glycol and iced
water at a temperature of 0 deg C. The resistance
should be 6 000 ohms. Slowly heat the mixture and measure the resis-
tance of the coolant temperature sensor at the follow-
ing temperatures. Compare the results with the spec-
ified values:

0 d e g C ................................................. 6 000 ohms
20 deg C .................................................. 2 500 ohms
30 deg C .................................................. 1 800 ohms
40 deg C.................................................. 1 200 ohms
70 deg C .......................................................450 ohms
90 degC .......................................................250 ohms
100 deg C.....................................................190 ohms
110 deg C.....................................................110 ohms
If the resistances obtained are not as specified at
any of the given temperatures, renew the coolant
temperature sensor and retest for fault codes.

(9) Disconnect the control unit wiring connec-
tors.
(10) Check the wiring harness for shorts and
continuity between the coolant temperature sensor
wiring connector terminals and the control unit wiring
connector terminals C10 and D2. Repair or renew the
wiring harness as necessary.
Also check the control unit terminals for damage.
If no fault is found, renew the control unit and
retest for fault codes.

To Remove and Install
(1) Disconnect the negative battery terminal.
(2) Disconnect the wiring connector from the
coolant temperature sensor.
(3) Drain the coolant as described in the Cooling
and Heating Systems section to a level below the
sensor.
(4) Unscrew the sensor from the thermostat
housing. Installation is a reversal of the removal procedure
with attention to the following points;

(1) Apply Loctite 675 or a similar conductive
sealer to the threads of th e sensor. Tighten the sensor
to the specified torque.
(2) Fill the cooling system with the correct
mixture of water and inhibitor as described in the
Cooling and Heating Systems section. (3) Ensure that the wiring connector is clean and
secure.
THROTTLE POSITION SENSOR
To Test - Codes 21 and 22

NOTE: The following test procedure as-
sumes that fault codes 21 or 22 have been
displayed during the se lf diagnosis test pro-
cedure. If no codes have been displayed but
the operation of the throttle position sensor
is suspect, begin the test procedure at oper-
ation (24).

(1) Erase the self diagnosis code memory as
previously described.
(2) Start and run the engine at idle speed for 60
seconds or until the ECM warning lamp lights. If the engine will not start, disconnect the throttle
position sensor wiring co nnector and proceed to
operation (8). .

(3) With the engine id ling, quickly increase the
engine speed to 3 000 rpm and return to idle.

If the ECM warning lamp remains illuminated,
proceed to operation (4).

If the ECM warning lamp extinguishes, an inter-
mittent fault is indicated. Proceed as follows:

(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connect or. Note any fault codes
displayed.

If codes 21 or 22 are displayed, proceed as
follows.

(5) Remove the jumper lead from the diagnostic
link connector. (6) Erase the self diagnosis codes as previously
described. (7) Disconnect the wiring connector from the
throttle position sensor. If code 22 was displayed in operation (4), proceed
to operation (13).

If code 21 was displayed in operation (4), proceed
as follows.

(8) Start and run the engine at idle speed for 2
minutes or until the ECM warning lamp lights. If the
engine will not start, pr oceed to operation (11).
(9) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on

Fuel and Engine Management 111


Location of the throttle position sensor. Inset shows the terminal identification.
the diagnostic link connector. Note any fault codes
displayed.

If code 21 is displayed, proceed to operation (11).
If code 22 is displayed, proceed as follows.
(10) Connect the lead of a test lamp to the
positive battery terminal and insert the probe into
terminal B on the throttle position sensor wiring
connector.

If the test lamp lights, pr oceed to operation (24).
If the test lamp does not light, check the wiring
harness between the throt tle position sensor wiring
connector terminal B and the control unit wiring
connector terminal D2 fo r continuity. Repair or
renew the wiring harness as necessary and retest for
fault codes.

(11) With the ignition switched Off, disconnect
the control unit wiring connectors. (12) With the ignition switched On, measure the
voltage at terminal C13 on the control unit wiring
connector.
If the voltage is less than 1 volt, check the wiring
harness for shorts between the throttle position sensor
wiring connector terminals C and A and the control
unit wiring connector terminals C13 and C14. Repair
or renew the wiring harness as necessary. If no fault
can be found, renew the control unit.

(13) Start and run the engine at idle speed.
(14) Connect a jumper lead across terminals A
and C on the throttle position sensor wiring connec-
tor. (15) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector . Note any fault codes
displayed. If codes 21 and 22 are displayed, proceed to
operation (24).

If code 22 only is displayed, proceed as follows.
(16) Remove the jumper lead from the throttle
position sensor wiring connector. (17) Measure the voltage across the throttle posi- tion sensor wiring connector terminals A and B.

If the voltage is below 4 volts, proceed to opera-
tion (20).

If the voltage is 4-6 volts, proceed as follows:
(18) With the ignition switched Off, disconnect
the control unit wiring connectors.
(19) Check the wiring harness between the con-
trol unit wiring connector terminal C13 and the
throttle position sensor wiring connector terminal C
for continuity and shorts. Repair or renew the wiring
harness as necessary and retest for fault codes. If no fault is found, renew the control unit and
retest for fault codes.

(20) Disconnect the wiring connector from the
MAP sensor. (21) Measure the voltage across the throttle posi-
tion sensor wiring connector terminals A and B.
If the voltage is 4 - 6 volts, renew the MAP sensor.
If the voltage is below 4 volts, proceed as follows.

(22) With the ignition switched Off, disconnect
the control unit wiring connectors. (23) Check the wiring harness between the con-
trol unit wiring connecto r terminal C14 and the
throttle position sensor wiring connector terminal A
for continuity and shorts. Repair or renew the wiring
harness as necessary and retest for fault codes. If no fault is found, renew the control unit and
retest for fault codes.

(24) With the ignition switched On, measure the
voltage at the control unit wiring connector terminal
C13.

If the voltage is 0.2-1.2 volts, proceed to opera-
tion (27).

If the voltage is 1.2-2.5 volts, proceed to opera-
tion (25).

If the voltage is over 2.5 volts, proceed as follows:
(a) Disconnect the wiring connector from the
throttle position sensor. (b) Measure the voltage at the control unit
wiring connector terminal C13. If the voltage is less than 1 volt, check the wiring
harness for continuity between the throttle position
sensor terminal B and the control unit wiring connec-
tor terminal D2. If the wiring harness is satisfactory,
renew the throttle position sensor.

(25) Check the base idle sp eed and adjust if
necessary as previously described. (26) With the ignition switched On, measure the
voltage at the control unit wiring connector terminal
C13. The voltage should be 0.2-1.2 volts. If the voltage is not as specified, renew the throttle
position sensor.

If the voltage is as specified, proceed as follows.
(27) With the ignition switched On, measure the
voltage at the control unit wiring connector terminal
C13 as the throttle is steadily opened to the wide open
throttle position. The voltage should increase steadily
with no sudden variations.

112 Fuel and Engine Management
If the voltage does not increase as specified, renew
the throttle position sensor.

If the voltage is as specified, proceed as follows.
(28) With the ignition switched On and the
throttle valve held fully open, measure the voltage at
control unit wiring connector terminal C13. The
voltage should be above 4 volts.

If the voltage is below 4 volts, renew the throttle
position sensor.

To Remove and Install
(1) Disconnect the negative battery terminal.
(2) On 1.6 liter engines, remove the air cleaner
assembly as previously described. (3) Disconnect the throttle position sensor wir-
ing connector. (4) Remove the throttle position sensor retain-
ing screws and remove the throttle position sensor
from the throttle body. Installation is a reversal of the removal procedure
with attention to the following points:

(1) Ensure that the throttle valve is in the fully
closed position. (2) Tighten the retaining screws securely and
install the wiring connector.

View of the throttle positi on sensor removed from the
throttle body assembly.
MANIFOLD AIR TEMPERATURE (MAT)
SENSOR - 1.8 LITRE ENGINE

To Test - Codes 23 and 25
(1) Erase the self diagnosis code memory as
previously described.
(2) Start and run the engine for 2 minutes or
until the ECM warning lamp lights. (3) Stop the engine, switch the ignition On and
connect a jumper lead between terminals A and B on
the diagnostic link connector . Note any fault codes
displayed. If codes 23 or 25 are displayed, proceed to
operation (4).

If codes 23 or 25 are not displayed but were
displayed when the self diagnosis test procedure was
originally performed, an intermittent fault is indi-
cated. Proceed as follows:

(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Disconnect the wiring connector from the
MAT sensor. (5) With the ignition switched On, measure the
voltage across the terminals on the MAT sensor wiring
connector. The voltage s hould be 4-6 volts.
If the voltage is below 4 volts, proceed to opera-
tion (9).

If the voltage is as specified, proceed as follows.
(6) Remove the MAT sensor from the engine.
(7) Connect an ohmmeter to the MAT sensor
terminals. (8) Immerse the metal end of the MAT sensor in
a container of iced water at a temperature of 4 deg C.
The resistance should be 7 500 ohms. Slowly heat the water and measure the resistance
of the MAT sensor at the following temperatures.
Compare the results with the specified values:

20 deg C .................................................. 3 400 ohms
38 deg C....................................................1 800 ohms
70 degC ...................................................... 450 ohms
100 deg C.................................................... 185 ohms
If the resistances obtained are not close to the
specified figures at any of the given temperatures,
renew the MAT sensor and retest for fault codes.

(9) Disconnect the control unit wiring connec-
tors. (10) Check the wiring harness between the MAT
sensor wiring connector and the control unit wiring
connector terminals C12 and A11 for shorts and
continuity. Also check the control unit terminals for
damage. Repair or renew the wiring harness as necessary.
If no fault is found, renew the control unit and
retest for fault codes.

To Remove and Install
(1) Disconnect the negative battery terminal.
Installed view of the MAT sensor. 1.8 liter engine.

Fuel and Engine Management 113
(2) Disconnect the wiring connector from the
MAT sensor.

(3) Unscrew the sensor from the inlet manifold.
Installation is a reversal of the removal procedure

with attention to the following points:
(1) Apply Loctite 567 or a similar conductive
sealer to the threads of th e sensor. Tighten the sensor
to the specified torque. (2) Ensure that the wiring connector is clean and
tight.
OXYGEN SENSOR

To Test - Code 13
(1) Run the engine until the normal operating
temperature is obtained. (2) With the ignition switched Off, connect a
jumper lead between terminals A and B on the
diagnostic link connector.
(3) Start and run the engi ne at approximately
1 600-1 800 rpm for 2 minutes and note the ECM
warning lamp.
If the ECM warning lamp flashes at the rate of
twice per second, proceed to operation (5).

If the ECM warning lamp flashes at the rate of
once per second or slower, proceed as follows.

(4) Remove the jumper lead from the diagnostic
link connector and run th e engine above 2 000 rpm
for 2 minutes, noting the ECM warning lamp.

If the ECM warning lamp lights, stop the engine,
switch the ignition On and connect a jumper lead
between terminals A and B on the diagnostic link
connector. If code 13 is displayed proceed to opera-
tion (5).

If the ECM warning lamp does not light, an
intermittent fault is indicated. Proceed as follows:

(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure.
(b) Check that all earth wires are secure.
(5) Switch the ignition Off and disconnect the
oxygen sensor wiring connector. Using a jumper lead
connect the oxygen sensor wiring connector to a
suitable engine earth. (6) Start and run the engi ne at approximately
1 600-1 800 rpm and note the ECM warning lamp.
The lamp may flash for a few seconds but should then
extinguish for at least 30 seconds.
If the ECM warning lamp functions as described,
proceed to operation (7).

If the ECM warning lamp does not function as
described proceed as follows:

(a) Check the wiring harness between the oxygen
sensor wiring connector and the control unit wiring
connector D7 for open circuits. Repair or renew the
wiring harness as necessary.

{b) Check the earth circuit between the control
unit wiring connect D6 and the right rear cylinder
head bolts. Repair or renew the wiring harness as
necessary.

(c) If no fault is found in (a) and (b) renew the
control unit and retest for fault codes.

(7) Check the wiring harness earth circuit be-
tween the control unit wiring connector D6 and the
right rear cylinder head bolts. Repair or renew the
wiring harness as necessary.

If no fault is found, thoroughly check the oxygen
sensor connector. If the conne ctor is not faulty, renew
the oxygen sensor.

To Test - Code 44
(1) Run the engine until normal operating tem-
perature is attained.
(2) With the ignition switched Off, connect a
jumper lead between terminals A and B on the
diagnostic link connector. (3) Start and run the engi ne at approximately
1 600-1 800 rpm for 2 minutes and note the ECM
warning lamp. If the ECM warning lamp is off more than on or
flashes at the rate of twice per second, proceed to
operation (4).

If the ECM warning lamp flashes evenly at the
rate of once per second an intermittent fault is
indicated. Proceed as follows:

(a) Check for faulty wiri ng connections. Check
that all wiring connectors are clean and secure. (b) Check that all earth wires are secure.
(4) Switch the engine Off and disconnect the
oxygen sensor wiring connector.
(5) Start and run the engine at 1 600-1 800 rpm
for at least 30 seconds and note the ECM warning
lamp. If the ECM warning lamp flashes at the rate of
twice per second procee d to operation (6).

If the ECM warning lamp extinguishes for at least
30 seconds, check the wiring harness between the
oxygen sensor wiring connector and the control unit
wiring connector terminal D7 for shorts to earth.

Repair or renew the wiring harness as necessary.
If no fault can be found in the wiring harness, renew
the control unit.

Installed view of the oxygen sensor.