1998 NISSAN PATROL Engine Control Workshop Manual

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

jB
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect EGRC-solenoid valve A, B
and throttle control solenoid valve har-
ness connector.
3. Turn ignition switch ``ON''.
4. Check voltage between terminal
V1
and ground with CONSULT or tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+Harness connectors
M21,E127
+10A fuse
+Harness for open or
short between EGRC-
solenoid valve A, B and
fuse
+Harness for open or
short between throttle
control solenoid valve
and fuse
If NG, repair harness or
connectors.
CHECK OUTPUT SIGNAL CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect ECM harness connector.
3. Check harness continuity between
ECM terminal
V1and terminalV2,
ECM terminal
103and terminalV2,
ECM terminal
109and terminalV2.
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 EGRC-
solenoid valve A, B and
ECM
+Harness for open or
short between throttle
control solenoid valve
and ECM
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENTS
(EGRC-solenoid valve A, B and throttle
control solenoid valve).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace malfunctioning
component(s).
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
SEF706V
SEF782V
SEF783V
.
.
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve (Cont'd)
EC-161

COMPONENT INSPECTION
EGR valve
Apply vacuum to EGR vacuum port with a hand vacuum pump.
EGR valve spring should lift.
If NG, replace EGR valve.
Throttle control valve
Apply vacuum to throttle control valve vacuum port with a hand
vacuum pump.
Throttle control valve should close.
If NG, replace throttle control valve.
EGRC-solenoid valve A, B and throttle control solenoid
valve
Check air passage continuity.
ConditionAir passage
continuity
betweenj
AandjB
Air passage
continuity
betweenj
AandjC
12V direct current supply
between terminals
V1
andV2
Ye s N o
No supply No Yes
If NG, replace solenoid valve(s).
MEF137D
SEF707V
MEC488B
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve (Cont'd)
EC-162

Start Signal
TEC443
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EC-163

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK OVERALL FUNCTION.
1. Turn ignition switch ``ON''.
2. Check ``START SIGNAL'' in
``DATA MONITOR'' mode with
CONSULT.
--------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------
1. Turn ignition switch to ``START''.
2. Check voltage between ECM
terminal
V20and ground.
Voltage:
Ignition switch ``START''
Battery voltage
Except above
Approximately 0V
NG
cOK
INSPECTION END
CHECK INPUT SIGNAL CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect ECM harness connector and
ignition switch harness connector.
3. Check harness continuity between ECM
terminal
V20and terminalV6.
Continuity should exist.
If OK, check harness for short to ground
and short to power.
OK
cNG
Check the following.
+Harness connectors
M52,F7
+7.5A fuse
+Fuse block
M3,E112
+Harness for open or short
between ECM and igni-
tion switch
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
Disconnect and reconnect harness connec-
tors in the circuit. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage and
check the connection of ECM harness con-
nector. Reconnect ECM harness connector
and retest.
INSPECTION END
IGN ``ON'' OFF
IGN ``START'' ONSEF625S
SEF109P
SEF785V
.
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Start Signal (Cont'd)
EC-164

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

TEC444
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Accelerator Position Switch (Cont'd)
EC-166