1998 NISSAN PATROL engine

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK OVERALL FUNCTION.
1. Start engine and warm it up to normal
operating temperature.
2. Perform diagnostic test mode II (Self-
diagnostic results).
Make sure that diagnostic trouble code
No. 55 is displayed.
3. Make sure that EGR valve spring
moves up and down (Use your ®nger)
under the following conditions.
At idle:
Spring moves up and down.
Revving engine from idle to 3,800
rpm:
Spring does not move.
4. Make sure that throttle control valve rod
moves up and down under the following
conditions.
At idle:
Rod moves up and down.
Revving engine from idle to 2,500
rpm:
Rod does not move.
NG
cOK
INSPECTION END
CHECK VACUUM SOURCES TO EGR
VALVE AND THROTTLE CONTROL
VALVE.
1. Disconnect vacuum hose to EGR valve.
2. Make sure that vacuum exists under
the following conditions.
At idle:
Vacuum should exist.
Revving engine from idle to 3,800
rpm:
Vacuum should not exist.
3. Disconnect vacuum hose to throttle
control valve.
4. Make sure that vacuum exists under
the following conditions.
At idle:
Vacuum should exist.
Revving engine from idle to 2,500
rpm:
Vacuum should not exist.
NG
cOK
CHECK COMPONENTS
(EGR valve and throttle
control valve).
(See page EC-162.)
NG
Replace malfunctioning
component(s).
jA
SEF702V
SEF703V
SEF704V
SEF705V
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve (Cont'd)
EC-159

jA
CHECK CONTROL FUNCTION.
1. Stop engine.
2. Turn ignition switch ``ON''.
3. Turn EGRC-solenoid valve A, B
and throttle control solenoid
valve ``ON'' and ``OFF'' in
``ACTIVE TEST'' mode with
CONSULT and check operating
sound.
--------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------
1. Check voltage between ECM
terminal
103and ground under
the following conditions.
Voltage:
At idle
0-1V
Revving engine from idle to
3,800 rpm
Battery voltage
2. Check voltage between ECM
terminal
109and ground under
the following conditions.
Voltage:
At idle
0-1V
Revving engine from idle to
2,600 rpm
Battery voltage
3. Check voltage between ECM
terminal
V1and ground under
the following conditions.
Voltage:
At idle
0-1V
Revving engine from idle to
2,500 rpm
Battery voltage
NG
cOK
CHECK VACUUM HOSE.
Check vacuum hose for
clogging, cracks or
improper connection.
jB
SEF682S
SEF683S
SEF816F
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve (Cont'd)
EC-160

Accelerator Position Switch
The accelerator position switch detects OFF-accelerator switch sig-
nal and Full-accelerator switch signal and send these signals to the
ECM. The ECM will then determine engine idle conditions. These
signals are also used for diagnosing the accelerator position sen-
sor.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FULL ACCEL SW+Ignition switch: ON
(Engine stopped)Accelerator pedal: depressed ON
Except above OFF
OFF ACCEL SW+Ignition switch: ON
(Engine stopped)Accelerator pedal: released ON
Accelerator pedal: slightly open OFF
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)
31 R/LAccelerator position switch
(Idle)Ignition switch ``ON''
Accelerator pedal fully releasedBATTERY VOLTAGE
(11 - 14V)
Ignition switch ``ON''
Accelerator pedal depressedApproximately 0V
32 W/GAccelerator position switch
(Full)Ignition switch ``ON''
Accelerator pedal releasedApproximately 0V
Ignition switch ``ON''
Accelerator pedal fully depressedBATTERY VOLTAGE
(11 - 14V)
SEF708V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EC-165

COMPONENT INSPECTION
Accelerator position switch
1. Disconnect accelerator position switch harness connector.
2. Check continuity between terminals
V5andV6.
Conditions Continuity
Accelerator pedal released Yes
Accelerator pedal depressed No
3. Check continuity between terminalsV4andV5.
Conditions Continuity
Accelerator pedal released No
Accelerator pedal fully depressed Yes
If NG, replace accelerator pedal assembly.
CAUTION:
If accelerator position sensor or ECM connector is
disconnected, perform the following procedures:
Select ``OFF ACCEL PO SIG'' in ``ACTIVE TEST'' mode.
Touch CLEAR.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Start and warm up engine. After engine has warmed up,
idle for 10 minutes.
SEF709V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Accelerator Position Switch (Cont'd)
EC-169

A/T Control
These circuit lines are used to control the smooth shifting up and
down of A/T during the hard acceleration/deceleration.
Voltage signals are exchanged between ECM and TCM.
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)
24 PU/W A/T signal No. 1Engine is running.
Idle speed6-8V
30 P A/T signal No. 3Engine is running.
Idle speedApproximately 0V
37 P/B A/T signal No. 2Engine is running.
Idle speed6-8V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EC-175

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK OVERALL FUNCTION.
1. Start engine and let it idle.
2. Check voltage between ECM terminals
V24,V30,V37and ground with CON-
SULT or tester.
NG
cOK
INSPECTION END
CHECK INPUT SIGNAL CIRCUIT-I.
1. Turn ignition switch ``OFF''.
2. Disconnect ECM harness connector
and TCM harness connector.
3. Check harness continuity between
ECM terminal
V24and terminalV5,
ECM terminal
V30and terminalV7,
ECM terminal
V37and terminalV6.
Continuity should exist.
OK
cNG
Check the following.
+Harness connectors
M51,F6
+Harness connectors
E106,M88
+Harness continuity
between ECM and TCM
If NG, repair harness or
connectors.
CHECK INPUT SIGNAL CIRCUIT-II.
Check harness continuity between ECM
terminal
V24and ground, ECM terminal
V30and ground, ECM terminalV37and
ground.
Continuity should not exist.
If OK, check harness for short to power.
OK
cNG
Check the following.
+Harness connectors
E106,M88
+Harness connectors
M51,F6
+Harness for short
between ECM and TCM
If NG, repair short to
ground or short to power in
harness or connectors.
Disconnect and reconnect harness con-
nectors in the circuit. 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
Terminal Voltage
V24and ground 6 - 8V
V30and ground Approximately 0V
V37and ground 6 - 8V
SEF792V
SEF795V
SEF796V
SEF797V
.
.
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
A/T Control (Cont'd)
EC-177

Charge Air Cooler Fan Control
SYSTEM DESCRIPTION
Crankshaft position sensor (TDC)cEngine speed
ECM
cCharge air cooler fan relayCharge air temperature sensorcCharge air temperature
Ignition switch
cStart signal
The ECM controls the charge air cooler fan operation corresponding to the engine speed, the charge air tem-
perature and the start signal. The control system has 2-step control [ON/OFF]. The ECM does not directly drive
the charge air cooler fan. It controls the ON/OFF charge air cooler fan relay, which in turn controls the charge
air cooler fan.
When the charge air temperature is above 67ÉC (153ÉF) and engine speed is more than 1,600 rpm, the charge
air cooler fan operates.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
I/C FAN RLY+When charge air cooler fan is stopped. OFF
+When charge air cooler fan operates. ON
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)
8 G/ORCharge air cooler fan
relayEngine is running.
Charge air cooler fan is not operating.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Charge air cooler fan is operating.0-1V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EC-178

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK OVERALL FUNCTION.
1. Turn ignition switch ``OFF''.
2. Disconnect charge air temperature sen-
sor harness connector.
3. Connect 150Wresistor to charge air
temperature sensor harness connector.
4. Start engine and keep engine speed at
2,000 rpm.
5. Make sure that charge air cooler fan
operates.
NG
cOK
INSPECTION END
CHECK POWER SUPPLY.
1. Stop engine.
2. Disconnect charge air cooler fan relay.
3. Turn ignition switch ``ON''.
4. Check voltage between terminals
V2,
V5and ground with CONSULT or
tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+Harness connectors
M21,E127
+10A fuse
+15A fuse
+Fuse block
M2
+Harness for open or
short between charge air
cooler fan relay and
fuses
If NG, repair harness or
connectors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect charge air cooler fan motor
harness connector.
3. Check harness continuity between relay
terminal
V3and motor terminalV1,
motor terminal
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
E127,M21
+Harness connectors
M50,F5
+Harness for open or
short between charge air
cooler fan relay and
charge air cooler fan
motor
+Harness for open or
short between charge air
cooler fan motor and
engine ground
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
jA
SEF710V
SEF798V
SEF712V
SEF799V
SEF711V
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Charge Air Cooler Fan Control (Cont'd)
EC-180