1998 NISSAN PATROL engine

INSPECTION START
Start engine.
Is engine running?
Ye s
cNo
CHECK POWER SUP-
PLY-I.
1. Turn ignition switch
``ON''.
2. Check voltage between
ECM terminal
V38and
ground with CONSULT
or tester.
Voltage: Battery volt-
age
If NG, check the following.
+Harness connectors
M51,F6+10A fuse
+Harness for open or
short between ECM and
fuse
If NG, repair harness or
connectors.
OK
Go to
``CHECK
GROUND CIRCUIT'' on
EC-68.
CHECK POWER SUPPLY-II.
1. Stop engine.
2. Check voltage between ECM terminal
V70and ground with CONSULT or
tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+Harness connectors
E127,M21+Harness connectorsM52,F7+7.5A fuse
+Harness for open or
short between ECM and
battery
If NG, repair harness or
connectors.
CHECK POWER SUPPLY-III.
1. Turn ignition switch ``ON'' and then
``OFF''.
2. Check voltage between ECM terminals
V56,V61,11 6,11 7and ground with
CONSULT or tester.
Voltage:
After turning ignition switch ``OFF'',
battery voltage will exist for a few
seconds, then drop to approximately
0V.
NG
cOK
Go to``CHECK
GROUND CIRCUIT'' on
EC-68.
Case-1: Battery voltage does
not exist.
Case-2: Battery voltage exists
for more than a few
seconds.
Case-1
cCase-2
Go to``CHECK ECCS
RELAY'' on next page.
jA
SEF065P
SEF056R
SEF566S
SEF567S
.
.
.
.
.
TROUBLE DIAGNOSIS FOR POWER SUPPLY
Main Power Supply and Ground Circuit
(Cont'd)
EC-66

jB
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM
terminals
V39,V43,106,11 2,11 8
and engine ground.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Joint connector
F18
+Harness for open or
short between ECM and
ground
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
Check ECM pin terminals for damage and
check the connection of ECM harness
connector.
INSPECTION END
SEF570S
.
.
.
TROUBLE DIAGNOSIS FOR POWER SUPPLY
Main Power Supply and Ground Circuit
(Cont'd)
EC-68

Camshaft Position Sensor (CMPS) (PUMP)
The camshaft position sensor (PUMP) is located on the electronic
fuel injection pump.
The sensor consists of a permanent magnet, core and coil.
When engine is running, gap between sensor and drive shaft rotat-
ing plate will periodically change. Permeability near the sensor also
changes.
Due to the permeability change, the magnetic ¯ux near the core is
changed. Therefore, the voltage signal generated in the coil is
changed.
The ECM receives the voltage signal (6 pulses/2 engine revolu-
tions).
These signals are used for tachometer indication.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
CKPSzRPM (REF)+Tachometer: Connect
+Run engine and compare tachometer indication with the CONSULT
value.Almost the same speed as the
CONSULT value.
CKPSzRPM-PUMP
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
28
33BCamshaft position sensor
(PUMP) groundEngine is running.
(Warm-up condition)
Idle speedApproximately 0V
41
45WCamshaft position sensor
(PUMP)Engine is running.
(Warm-up condition)
Idle speedApproximately 0V
SEF722V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 0V
SEF723V
SEF674V
TROUBLE DIAGNOSIS FOR ``CAM POS SEN (PUMP)'' (DTC 11)
EC-69

ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble Code
No.Malfunction is detected when ....Check Items
(Possible cause)
11+An improper signal from the sensor is detected by
ECM during engine running.+Harness or connectors
[The camshaft position sensor (PUMP) circuit is open
or shorted.]
+Camshaft position sensor (PUMP)
DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
1) Turn ignition switch ``ON'' and select ``DATA MONITOR''
mode with CONSULT.
2) Start engine and run it for at least 2 seconds at idle
speed.
(If engine does not run, turn ignition switch to ``START''
for at least 2 seconds.)
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Start engine and run it for at least 2 seconds at idle
speed.
(If engine does not run, turn ignition switch to ``START''
for at least 2 seconds.)
2) Turn ignition switch ``OFF'', wait at least 5 seconds and
then ``ON''.
3) Perform ``Diagnostic Test Mode II (Self-diagnostic
results)'' with ECM.
SEF714V
TROUBLE DIAGNOSIS FOR ``CAM POS SEN (PUMP)'' (DTC 11)
Camshaft Position Sensor (CMPS) (PUMP)
(Cont'd)
EC-70

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK INPUT SIGNAL CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect electronic fuel injection
pump harness connector and ECM har-
ness connector.
3. Check harness continuity between ter-
minal
V1and ECM terminalsV41,V45.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Repair open circuit or short
to ground or short to power
in harness or connectors.
CHECK GROUND CIRCUIT-I.
1. Turn ignition switch ``OFF''.
2. Check harness continuity between ter-
minal
V2and ECM terminalsV28,V33.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Repair open circuit or short
to ground or short to power
in harness or connectors.
CHECK GROUND CIRCUIT-II.
1. Loosen and retighten engine ground
screws.
2. Check harness continuity between ter-
minal
V3and engine ground.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Joint connector
F19
+Harness for open or
short between electronic
fuel injection pump and
engine ground
If NG, repair harness or
connectors.
CHECK COMPONENT
[Camshaft position sensor (PUMP)].
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace camshaft position
sensor (PUMP).
Disconnect and reconnect harness connec-
tors in the circuit. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage or
the connection of ECM harness connector.
Reconnect ECM harness connector and
retest.
INSPECTION END
SEF675V
SEF731V
SEF732V
SEF676V
SEF733V
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``CAM POS SEN (PUMP)'' (DTC 11)
Camshaft Position Sensor (CMPS) (PUMP)
(Cont'd)
EC-72

Mass Air Flow Sensor (MAFS)
COMPONENT DESCRIPTION
The mass air ¯ow sensor is placed in the stream of intake air. It
measures the intake air ¯ow rate by measuring a part of the entire
intake air ¯ow. It consists of a hot wire that is supplied with electric
current from the ECM. The temperature of the hot wire is controlled
by the ECM a certain amount. The heat generated by the hot wire
is reduced as the intake air ¯ows around it. The more air, the
greater the heat loss.
Therefore, the ECM must supply more electric current to the hot
wire as air ¯ow increases. This maintains the temperature of the hot
wire. The ECM detects the air ¯ow by means of this current change.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS AIR/FL SE+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle 1.6 - 2.0V
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values, and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC voltage)
35 R Mass air ¯ow sensorEngine is running.
(Warm-up condition)
Idle speed1.6 - 2.0V
50 B Sensors' groundEngine is running.
(Warm-up condition)
Idle speedApproximately 0V
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble
Code No.Malfunction is detected when ...Check Items
(Possible Cause)
12+An excessively high or low voltage from the sensor is
sent to ECM.+Harness or connectors
(The sensor circuit is open or shorted.)
+Mass air ¯ow sensor
SEF734V
TROUBLE DIAGNOSIS FOR ``MASS AIR FLOW SEN'' (DTC 12)
EC-74

DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE
1) Turn ignition switch ``ON'', and wait at least 6 seconds.
2) Select ``DATA MONITOR'' mode with CONSULT.
3) Start engine and wait at least 3 seconds.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Turn ignition switch ``ON'', and wait at least 6 seconds.
2) Start engine and wait at least 3 seconds.
3) Turn ignition switch ``OFF'', wait at least 5 seconds and
then turn ``ON''.
4) Perform ``Diagnostic Test Mode II (Self-diagnostic
results)'' with ECM.
SEF735V
TROUBLE DIAGNOSIS FOR ``MASS AIR FLOW SEN'' (DTC 12)
Mass Air Flow Sensor (MAFS) (Cont'd)
EC-75

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect mass air ¯ow sensor har-
ness connector.
3. Turn ignition switch ``ON''.
4. Check voltage between terminal
V1and ground with CONSULT or tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+Harness connectors
M52,F7+Harness for open or
short between mass air
¯ow sensor and ECM
+Harness for open or
short between mass air
¯ow sensor and ECCS
relay
If NG, repair harness or
connector.
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Loosen and retighten engine ground
screws.
3. Check harness continuity between ter-
minal
V2and engine ground.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Harness connectors
E106,M88+Harness connectorsM51,F6+Harness for open or
short between mass air
¯ow sensor and ECM
+Harness for open or
short between mass air
¯ow sensor and TCM
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK INPUT SIGNAL CIRCUIT.
1. Disconnect ECM harness connector.
2. Check harness continuity between ter-
minal
V3and ECM terminalV35.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Repair open circuit or short
to ground or short to power
in harness or connectors.
CHECK COMPONENT
(Mass air ¯ow sensor).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace mass air ¯ow sen-
sor.
Disconnect and reconnect harness con-
nectors in the circuits. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage and
check the connection of ECM harness
connector. Reconnect ECM harness con-
nector and retest.
INSPECTION END
SEF713V
SEF736V
SEF676V
SEF737V
SEF738V
.
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``MASS AIR FLOW SEN'' (DTC 12)
Mass Air Flow Sensor (MAFS) (Cont'd)
EC-77