1998 NISSAN PATROL ignition

Precautions
+Before connecting or disconnecting the ECM harness
connector, turn ignition switch OFF and disconnect nega-
tive battery terminal. Failure to do so may damage the ECM
because battery voltage is applied to ECM even if ignition
switch is turned off.
+When connecting ECM harness connector, tighten secur-
ing bolt until the gap between orange indicators disap-
pears.
: 3.0 - 5.0 Nzm (0.3 - 0.5 kg-m, 26 - 43 in-lb)
+When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminal, when connecting pin connectors.
+Before replacing ECM, perform Terminals and Reference
Value inspection and make sure ECM functions properly.
Refer to EC-54.
+If MIL illuminates or blinks irregularly when engine is
running, water may have accumulated in fuel ®lter. Drain
water from fuel ®lter. If this does not correct the problem,
perform speci®ed trouble diagnostic procedures.
+After performing each TROUBLE DIAGNOSIS, perform
``OVERALL FUNCTION CHECK'' or ``DTC (Diagnostic
Trouble Code) CONFIRMATION PROCEDURE''.
The DTC should not be displayed in the ``DTC CONFIRMA-
TION PROCEDUREº if the repair is completed. The ``OVER-
ALL FUNCTION CHECK'' should be a good result if the
repair is completed.
SEF289H
SEF308Q
SEF291H
MEF040D
SEF051P
PRECAUTIONS AND PREPARATION
EC-6

System Chart
Camshaft position sensor (PUMP)c
ECM
(ECCS-D
control
module)
Crankshaft position sensor (TDC)c
Control sleeve position sensorc
Fuel temperature sensorc
Engine coolant temperature sensorc
Needle lift sensorc
Accelerator position sensorc
Accelerator position switchc
Accelerator switch (F/C)c
Neutral position switchc
Ignition switchc
Battery voltagec
Vehicle speed sensorc
Air conditioner switchc
Mass air ¯ow sensorc
Charge air temperature sensorc
Heat up switchc
Fuel injection controlcElectric governor
Fuel injection timing controlcInjection timing control valve
Fuel cut controlcFuel cut solenoid valve
Glow control systemcGlow relay & glow lamp
On board diagnostic systemcMalfunction indicator lamp
(On the instrument panel)
EGR valve & throttle control
valve controlcEGRC-solenoid valve A, B &
throttle control solenoid valve
Cooling fan controlcCooling fan relay
Air conditioning cut controlcAir conditioner relay
Charge air cooler fan controlcCharge air cooler fan relay
ENGINE AND EMISSION CONTROL OVERALL SYSTEM
EC-14

Fuel Injection System
SYSTEM DESCRIPTION
Three types of fuel injection control are provided to accommodate engine operating conditions; normal control,
idle control and start control. The ECM determines the appropriate fuel injection control. Under each control,
the amount of fuel injected is compensated to improve engine performance. The ECM performs duty control
on the electric governor (built into the fuel injection pump) according to sensor signals to compensate the
amount of fuel injected to the preset value.
START CONTROL
Input/output signal line
Engine coolant temperature sensorcEngine coolant temperature
ECM
cElectric
governorCrankshaft position sensor (TDC)cEngine speed
Ignition switch
cStart signal
Control sleeve position sensor
cControl sleeve position
When the ECM receives a start signal from the ignition switch, the
ECM adapts the fuel injection system for the start control. The
amount of fuel injected at engine starting is a preset program value
in the ECM. The program is determined by the engine speed and
engine coolant temperature.
For better startability under cool engine conditions, the lower the
coolant temperature becomes, the greater the amount of fuel
injected. The ECM ends the start control when the engine speed
reaches 400 rpm (for M/T models), 600 rpm (for A/T models) and
shifts the control to the normal or idle control.
SEF648S
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
EC-15

Fuel Injection Timing System
SYSTEM DESCRIPTION
The fuel injection timing system provides the optimal fuel injection timing for the target amount of fuel injected
according to engine speed. The timing is compensated when the vehicle is being driven or when starting
depending on the engine coolant temperature.
The ECM performs duty control on the timing control valve, allowing the valve to provide optimal fuel injection
timing. The ECM also performs feedback control on the timing control valve using the signal from the needle
lift sensor which detects the actual fuel injection timing.
BASIC CONTROL
Input/output signal line
Crankshaft position sensor (TDC)cEngine speed
ECM
c
Injection
timing con-
trol valve
Needle lift sensorcInjection timing
The optimal fuel injection timing data, predetermined in proportion
to engine speeds and amount of fuel injected, are stored in the
ECM memory. The ECM uses the data to control the fuel injection
timing.
ENGINE COOLANT TEMPERATURE COMPENSATION (When starting)
Input/output signal line
Crankshaft position sensor (TDC)cEngine speed
ECM
c
Injection
timing con-
trol valveEngine coolant temperature sensorcEngine coolant temperature
Needle lift sensor
cIgnition timing
Ignition switch
cStart signal
For better startability under cool engine conditions, the fuel injec-
tion timing is compensated according to the engine coolant tem-
perature.
SEF650S
SEF651S
Fuel injection
timing compensation
Engine coolant
temperature
Engine rpm
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
EC-18

DTC and MIL Detection Logic
When a malfunction is detected for the ®rst time, the malfunction (DTC) is stored in the ECM memory.
The MIL will light up each time the ECM detects malfunction. However, if the same malfunction is experienced
in two consecutive driving patterns and the engine is still running, the MIL will stay lit up. For diagnostic items
causing the MIL to light up, refer to ``DIAGNOSTIC TROUBLE CODE INDEX'', EC-1.
Diagnostic Trouble Code (DTC)
HOW TO READ DTC
The diagnostic trouble code can be read by the following methods.
1. The number of blinks of the malfunction indicator lamp in the Diagnostic Test Mode II (Self-Diagnostic
Results) Examples: 11, 13, 14, etc.
These DTCs are controlled by NISSAN.
2. CONSULT Examples: ``CAM POS SEN (PUMP)'', etc.
+Output of the trouble code means that the indicated circuit has a malfunction. However, in the Mode
II it does not indicate whether the malfunction is still occurring or occurred in the past and returned
to normal.
CONSULT can identify them. Therefore, using CONSULT (if available) is recommended.
HOW TO ERASE DTC
The diagnostic trouble code can be erased by the following methods.
Selecting ``ERASE'' in the ``SELF-DIAG RESULTS'' mode with CONSULT.
Changing the diagnostic test mode from Diagnostic Test Mode II to Mode I. (Refer to EC-32.)
+If the battery terminal is disconnected, the diagnostic trouble code will be lost within 24 hours.
+When you erase the DTC, using CONSULT is easier and quicker than switching the diagnostic test
modes.
HOW TO ERASE DTC (With CONSULT)
1. If the ignition switch stays ``ON'' after repair work, be sure to turn ignition switch ``OFF'' once. Wait at least
5 seconds and then turn it ``ON'' (Engine stopped) again.
2. Turn CONSULT ``ON'' and touch ``ENGINE''.
3. Touch ``SELF-DIAG RESULTS''.
4. Touch ``ERASE''. (The DTC in the ECM will be erased.)
HOW TO ERASE DTC (No Tools)
1. If the ignition switch stays ``ON'' after repair work, be sure to turn ignition switch ``OFF'' once. Wait at least
5 seconds and then turn it ``ON'' again.
2. Change the diagnostic test mode from Mode II to Mode I. (Refer to EC-32.)
SEF691S
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
EC-30

Malfunction Indicator Lamp (MIL)
1. The malfunction indicator lamp will light up when the ignition
switch is turned ON without the engine running. This is a bulb
check.
+If the malfunction indicator lamp does not light up, refer to EL
section (``WARNING LAMPS AND CHIME'') or see EC-188.
2. When the engine is started, the malfunction indicator lamp
should go off.
If the lamp remains on, the on board diagnostic system has
detected an engine system malfunction.
If MIL illuminates or blinks irregularly after starting engine,
water may have accumulated in fuel ®lter. Drain water from
fuel ®lter.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following three functions.
1. BULB CHECK : This function checks the MIL bulb for damage (blown, open circuit,
etc.).
2. MALFUNCTION
WARNING: This is a usual driving condition. When a malfunction is detected, the
MIL will light up to inform the driver that a malfunction has been
detected.
3. SELF-DIAGNOSTIC
RESULTS: This function allows diagnostic trouble codes to be read.
Refer to ``HOW TO SWITCH DIAGNOSTIC TEST MODES'' on next page.
ConditionDiagnostic
Test Mode IDiagnostic
Test Mode II
Ignition switch
in ``ON'' posi-
tion
Engine
stopped
BULB CHECKSELF-DIAGNOSTIC
RESULTS
Engine
running
MALFUNCTION
WARNINGÐ
SEF051P
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
EC-31

HOW TO SWITCH DIAGNOSTIC TEST MODES
Turn ignition switch ``ON''.
(Do not start engine.)
c
Diagnostic Test Mode I Ð BULB CHECK.
Refer to previous page.
MIL should come on.
.
OK
cNG
Check MIL circuit.
(See EC-188.)
OK
.
cNG
Repair harness or
connectors.
OK
b
cG
Start engine.
cDiagnostic Test
Mode I
Ð MALFUNC-
TION WARN-
ING.
Refer to previ-
ous page.
Data link connector for CONSULT
(Connect CHK and IGN terminals with a suitable
harness.)
MIL should go off.
cNG
Check MIL circuit and data link connector for
CONSULT circuit. (See EC-188.)
OK
.
NG
Repair harness or
connectors.
OK
Wait at least 2 seconds.
.b
Data link connector for CONSULT
(Disconnect the suitable harness between CHK
and IGN terminals.)
DIAGNOSTIC TEST MODE II
Ð SELF-DIAGNOSTIC RESULTS
.jBjA
.
.
.
.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-32

jB
m
jA
Data link connector for CONSULT
(Connect CHK and IGN terminals with a suit-
able harness.)
Wait at least 2 seconds.
Data link connector for CONSULT
(Disconnect the suitable harness between
CHK and IGN terminals.)
If the suitable harness is disconnected at this
time, the diagnostic trouble code will be
erased from the backup memory in the ECM.
+Switching the modes is not possible when the engine
is running.
+When ignition switch is turned off during diagnosis,
power to ECM will drop after approx. 5 seconds.
The diagnosis will automatically return to Diagnostic
Test Mode I..
.
.
.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-33