1998 NISSAN PICK-UP Repair Manual

Description for Work Flow
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using the
``DIAGNOSTIC WORK SHEET'', EC-54.
STEP IIBefore confirming the concern, check and write down (print out using CONSULT) the Diagnostic Trouble Code
(DTC), then erase the code. (Refer to EC-36.) The DTC can be used when duplicating the incident at STEP III &
IV.
Study the relationship between the cause, specified by DTC, and the symptom described by the customer. (The
``Symptom Matrix Chart'' will be useful. See page EC-62.)
Also check related service bulletins for information.
STEP IIITry to confirm the symptom and under what conditions the incident occurs.
The ``DIAGNOSTIC WORK SHEET'' is useful to verify the incident. Connect CONSULT to the vehicle in DATA
MONITOR (AUTO TRIG) mode and check real time diagnosis results.
If the incident cannot be verified, perform INCIDENT SIMULATION TESTS. (Refer to GI section.)
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the Diagnostic Trouble Code by driving in (or performing) the ``DTC CONFIRMATION PROCEDURE''.
Check and read the DTC by using CONSULT.
During the DTC verification, be sure to connect CONSULT to the vehicle in DATA MONITOR (AUTO TRIG) mode
and check real time diagnosis results.
If the incident cannot be verified, perform INCIDENT SIMULATION TESTS. (Refer to GI section.)
In case the ``DTC CONFIRMATION PROCEDURE'' is not available, perform the ``OVERALL FUNCTION CHECK''
instead. The DTC cannot be displayed by this check, however, this simplified ``check'' is an effective alternative.
The ``NG'' result of the ``OVERALL FUNCTION CHECK'' is the same as the DTC detection.
STEP VTake the appropriate action based on the results of STEP I through IV.
If the malfunction code is indicated, proceed to TROUBLE DIAGNOSIS FOR DTC XX.
If the normal code is indicated, proceed to the BASIC INSPECTION on next page. Then perform inspections
according to the Symptom Matrix Chart. (Refer to EC-62.)
STEP VIIdentify where to begin diagnosis based on the relationship study between symptom and possible causes. Inspect
the system for mechanical binding, loose connectors or wiring damage using (tracing) ``Harness Layouts''.
Gently shake the related connectors, components or wiring harness with CONSULT set in ``DATA MONITOR
(AUTO TRIG)'' mode.
Check the voltage of the related ECM terminals or monitor the output data from the related sensors with CON-
SULT. Refer to EC-64, EC-68.
The ``DIAGNOSTIC PROCEDURE'' in EC section contains a description based on open circuit inspection. A short
circuit inspection is also required for the circuit check in the DIAGNOSTIC PROCEDURE. For details, refer to GI
section (``HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENT'', ``Circuit Inspection'').
Repair or replace the malfunction parts.
STEP VIIOnce you have repaired the circuit or replaced a component, you need to run the engine in the same conditions
and circumstances which resulted in the customer's initial complaint.
Perform the ``DTC CONFIRMATION PROCEDURE'' and confirm the normal code (Diagnostic trouble code No. 55)
is detected. If the incident is still detected in the final check, perform STEP VI by using a different method from the
previous one.
Before returning the vehicle to the customer, be sure to erase the unnecessary (already fixed) DTC in ECM. (Refer
to EC-36.)
TROUBLE DIAGNOSIS Ð Work FlowKA
EC-57

Basic Inspection
Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
lHeadlamp switch is OFF,
lAir conditioner switch is OFF,
lRear window defogger switch is OFF,
lSteering wheel is in the straight-ahead position, etc.
BEFORE STARTING
1. Check service records for any recent
repairs that may indicate a related
problem, or the current need for sched-
uled maintenance.
2. Open engine hood and check the fol-
lowing:
lHarness connectors for improper con-
nections
lVacuum hoses for splits, kinks, or
improper connections
lWiring for improper connections,
pinches, or cuts
CONNECT CONSULT TO THE
VEHICLE.
Connect ``CONSULT'' to the data link
connector for CONSULT and select
``ENGINE'' from the menu. Refer to
EC-45.
CHECK IGNITION TIMING.
1. Warm up engine sufficiently.
2. Select ``IGN TIMING ADJ'' in
``WORK SUPPORT'' mode.
3. Touch ``START''.
4. Check ignition timing at idle
using timing light.
Ignition timing:
10É 2É BTDC
----------------------------------------------------------------------------------------------------------------------------------OR----------------------------------------------------------------------------------------------------------------------------------
1. Warm up engine sufficiently.
2. Stop engine and disconnect
throttle position sensor sub-
harness connector.
3. Start engine.
4. Check ignition timing at idle
using timing light.
Ignition timing:
10É 2É BTDC
OK
cNG
Adjust ignition timing by
turning camshaft position
sensor.
VA
(Go to next page.)
SEF142I
SEF056UA
SEF555N
SEF148U
SEF284G
.
.
.
TROUBLE DIAGNOSIS Ð Basic InspectionKA
EC-58

VA
CHECK IDLE SPEED ADJ.
SCREW INITIAL SET RPM (BASE
IDLE SPEED).
1. Select ``IGN TIMING
ADJ'' in ``WORK SUP-
PORT'' mode.
2. When touching
``START'', does engine
speed fall to 750 25
rpm?
-----------------------------------------------------------------------------------------------------------OR -----------------------------------------------------------------------------------------------------------
When disconnecting throttle
position sensor sub-har-
ness connector, does
engine run at 750 25 rpm?
OK
cNG
Adjust base idle speed by turning
idle speed adjusting screw.
CHECK THROTTLE POSITION
SENSOR IDLE POSITION.
1. Perform ``THRTL POS
SEN ADJ'' in ``WORK
SUPPORT'' mode.
2. Check output voltage of
throttle position sensor.
Voltage: 0.35 - 0.65V
-----------------------------------------------------------------------------------------------------------OR -----------------------------------------------------------------------------------------------------------
1. Reconnect throttle posi-
tion sensor sub-harness
connector.
2. Check output voltage
between throttle position
sensor terminal
V2and
ground with voltmeter.
Voltage: 0.35 - 0.65V
OK
cNG
Adjust output voltage to 0.5V by
rotating throttle position sensor
body.
RESET IDLE POSITION
MEMORY.
1. Disconnect throttle position
sensor sub-harness connector.
2. Warm up engine sufficiently.
3. Select ``CLSD THL/
POSI'' in ``DATA MONI-
TOR'' mode (Manual
trigger) with CONSULT,
then stop engine.
4. Reconnect throttle position
sensor sub-harness connector.
5. Start engine and wait for a few
seconds.
6. Turn ignition switch ``OFF'' and
wait at least 5 seconds.
7.
Repeat steps 5. and 6.
until ``CLSD THL/POSI''
in ``DATA MONITOR''
mode with CONSULT
changes to ``ON''.
Repeat steps 5. and 6.
10 times.
b
VB
(Go to next page.)
SEF546N
SEF149U
.
.
.
.
TROUBLE DIAGNOSIS Ð Basic InspectionKA
Basic Inspection (Cont'd)
EC-59

VB
CHECK TARGET IDLE SPEED.
Read the engine idle speed in
``DATA MONITOR'' mode with
CONSULT.
800 50 rpm
----------------------------------------------------------------------------------------------------------------------------------OR----------------------------------------------------------------------------------------------------------------------------------
Check idle speed.
800 50 rpm
OK
cNG
Adjust idle speed. Refer to
EC-25.
After this inspection, unnecessary diag-
nostic trouble code No. might be dis-
played.
Erase the stored memory in ECM.
Refer to ``ON BOARD DIAGNOSTIC
SYSTEM DESCRIPTION'' (EC-36).
OK
INSPECTION END
.
.
.
TROUBLE DIAGNOSIS Ð Basic InspectionKA
Basic Inspection (Cont'd)
EC-60

Fail-Safe Chart
The ECM enters fail-safe mode, if any of the following malfunctions are detected due to the open or short
circuit.
When the ECM enters the ECM fail-safe mode listed in the last column below, the MIL illuminates.
DTC No.Detected
itemsEngine operating condition in fail-safe mode
12Mass air
flow sensor
circuitEngine speed will not rise more than 2,400 rpm due to the fuel cut.
13 Engine cool-
ant tempera-
ture sensor
circuitEngine coolant temperature will be determined by ECM based on the time after turning ignition switch
``ON'' or ``START''.
CONSULT displays the engine coolant temperature decided by ECM.
41 Intake air
temperature
sensor cir-
cuitThe ECM controls on the assumption that the intake air temperature is 20ÉC (68ÉF).
43 Throttle
position sen-
sor circuitThrottle position will be determined based on the amount of mass air flow and the engine speed.
Therefore, acceleration will be poor.
Unable to
access Diag-
nostic Test
Mode IIECMECM fail-safe activating condition
The computing function of the ECM was judged to be malfunctioning.
When the fail-safe system activates, i.e. if the ECM detects a malfunction condition in the CPU of
ECM, the MALFUNCTION INDICATOR LAMP on the instrument panel lights to warn the driver.
However, it is not possible to access ECCS and DTC cannot be confirmed.
Engine control with ECM fail-safe
When the fail-safe system is operating, fuel injection, ignition timing, fuel pump operation and IACV-
AAC valve operation are controlled under certain limitations.
Replace ECM, if ECM fail-safe condition is confirmed.
ConditionEngine coolant temperature decided
(CONSULT display)
Just as ignition switch is turned ON or START 20ÉC (68ÉF)
More than 6 minutes after ignition START 80ÉC (176ÉF)
Except as shown above20 - 80ÉC (68 - 176ÉF)
(Depends on the time)
Driving condition
When engine is idling Normal
When accelerating Poor acceleration
ECM fail-safe operation
Engine speed Engine speed will not rise more than 3,000 rpm.
Fuel injection Simultaneous multiport fuel injection system
Ignition timing Ignition timing is fixed at the preset value.
Fuel pumpFuel pump relay is ``ON'' when engine is running and ``OFF'' when
engine stalls.
IACV-AAC valve Full open
TROUBLE DIAGNOSIS Ð General DescriptionKA
EC-61

Symptom Matrix Chart
SYMPTOM
Reference page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
OVERCOOLS
OVERCHARGING
Warranty Symptom Code AA AB AC AD AE AF AG AH AJ AK AL AM HA 1P 1X
Basic engine control system
Fuel Fuel pump circuitllljlljjjEC-151
Fuel pressure regulator system
llljljlljlEC-22
Injector circuit
llljlll lEC-144
Evaporative emission systemjjjj
ljjjj jEC-19
Air Positive crankcase ventilation systemjjjj
ljjjj jjEC-21
Incorrect idle speed adjustmentjj jjjj jEC-25
Swirl control valve circuitjj
lEC-161
IACV-AAC valve circuit
llljllllljjEC-131
IACV-FICD solenoid valve circuitjjjjjjjjj jEC-168
Ignition Incorrect ignition timing adjustmentjj
lll ll lEC-25
Ignition circuit
lllll ll lEC-99
EVAP EVAP canister purge control solenoid
valve circuit
ljjjj j jEC-140
Main power supply and ground circuit
llljj jj jj jEC-75
Air conditioner circuitjjjjjjjjj j jHA section
ECCS system
ECCS Camshaft position sensor circuitllllljj jEC-82
Mass air flow sensor circuit
lllll ljjEC-89
Heated oxygen sensor circuit
lljlljlEC-123, 127
Engine coolant temperature sensor circuit
llljllljjlEC-95
Throttle position sensor circuit
ll lllll lEC-113
Incorrect throttle position sensor adjust-
ment
ljjljjljEC-58
Vehicle speed sensor circuitjj j jEC-118
ECMjjjjjjjjjjjEC-61
Start signal circuitjEC-149
Neutral position switch circuitjjjj jEC-136
Power steering oil pressure switch circuitjjjEC-157
l; High Possibility Item
j; Low Possibility Item(continued on next page)
TROUBLE DIAGNOSIS Ð General DescriptionKA
EC-62

SYSTEM
Ð Engine mechanical & otherSYMPTOM
Reference page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
OVERCOOLS
OVERCHARGING
Warranty Symptom Code AA AB AC AD AE AF AG AH AJ AK AL AM HA 1P 1X
Fuel Fuel tank
ll
Ð Fuel piping
lljjljj j
Vapor lockj
Valve depositjjjjj jj j
Poor fuel (Heavy weight gasoline, Low
octane)jjjjj jj j
Air Air ductjjjjj j
Air cleanerj
llljj
Air leakage from air duct
(Mass air flow sensor Ð throttle body)jjjjjjjjj j
Throttle body, Throttle wirej
lljlljj jFE section
Air leakage from intake manifold/
Collector/Gasketj
ljjjjljjlÐ
Cranking Batteryjjjjjj jjj
EL section Alternator circuitjjjjjj jjj
Starter circuit
l
FlywheellÐ
Engine Cylinder head
ljljjljj
Ð Cylinder head gasketjjjjj
ljljj
Cylinder blockjjjj
ljj jj
Pistonjjjjj j
ljl
Piston ringjjjjlljjl
Connecting rodljjjj jj j
Bearing
lljljjlj
Crankshaftjjjjj jj j
Valve
mechanismTiming chain
ljljljj j
Camshaft
ljjjj jj j
Intake valvej
lljjljjj
Exhaust valve
ljljlljjl
Exhaust Exhaust manifold/Tube/Muffler/Gasketjllll ljl
Three way catalystjljjljj j
Lubrication Oil pan/Oil strainer/Oil pump/Oil filter/Oil
gallery
ljjlljj jl
Oil level (Low)/Filthy oiljjjjj jj jj
Cooling Radiator/Hose/Radiator filler capjjjjj jj
lj
Thermostatjjjjjj
ljjljj
Water pump
ljjjj jjlj
Water galleryjjjjj jj jj
Cooling fanjjjj
ljljjljj
Coolant level (low)/Contaminated coolantjjjjj jj jj
l; High Possibility Item
j; Low Possibility Item
TROUBLE DIAGNOSIS Ð General DescriptionKA
Symptom Matrix Chart (Cont'd)
EC-63

CONSULT Reference Value in Data Monitor
Mode
Remarks:
lSpecification data are reference values.
lSpecification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data
in spite of the ignition timing not being adjusted to the specification data. This IGN TIMING monitors the data calculated by the
ECM according to the signals input from the camshaft position sensor and other ignition timing related sensors.
lIf the real-time diagnosis results are NG and the on board diagnostic system results are OK when diagnosing the mass air flow
sensor, first check to see if the fuel pump control circuit is normal.
MONITOR ITEM CONDITION SPECIFICATION
CMPScRPM (POS)
lTachometer: ConnectlRun engine and compare tachometer indication with the CONSULT value.Almost the same speed as the CON-
SULT value.
MAS AIR/FL SE
lEngine: After warming uplAir conditioner switch: ``OFF''lShift lever: Neutral positionlNo-loadIdle 1.3 - 1.7V
2,500 rpm 1.7 - 2.1V
COOLAN TEMP/S
lEngine: After warming up More than 70ÉC (158ÉF)
O2 SEN
lEngine: After warming up Maintaining engine speed at 2,000 rpm0 - 0.3V«0.6 - 1.0V
M/R F/C MNTRLEAN«RICH
Changes more than 5 times
during 10 seconds.
VHCL SPEED SE
lTurn drive wheels and compare speedometer indication with the CONSULT
valueAlmost the same speed as
the CONSULT value
BATTERY VOLT
lIgnition switch: ON (Engine stopped) 11 - 14V
THRTL POS SEN
lIgnition switch: ON
(Engine stopped)Throttle valve: fully closed 0.35 - 0.65V
Throttle valve: fully opened Approx. 4.0V
START SIGNAL
lIgnition switch: ON®START®ON OFF®ON®OFF
CLSD THL/POSI
lIgnition switch: ON
(Engine stopped)Throttle valve: Idle position ON
Throttle valve: Slightly open OFF
AIR COND SIG
lEngine: After warming up, idle the
engineAir conditioner switch: ``OFF'' OFF
Air conditioner switch: ``ON''
(Compressor operates.)ON
P/N POSI SW
lIgnition switch: ONShift lever: Neutral position ON
Except above OFF
PW/ST SIGNAL
lEngine: After warming up, idle the
engineSteering wheel in neutral position
(forward direction)OFF
The steering wheel is turned ON
TROUBLE DIAGNOSIS Ð General DescriptionKA
EC-64