2000 NISSAN PATROL engine

On board diagnostic system function
The on board diagnostic system has the following three func-
tions.
Diagnostic Test Mode KEY and ENG. Status Function Explanation of Function
Mode I Ignition switch in ON
position
Engine stopped
BULB CHECK This function checks the MI bulb for damage
(blown, open circuit, etc.).
If the MI does not come on, check MI circuit.
(See EC-1276.)
Engine running
MALFUNCTION
WARNINGThis is a usual driving condition. When ECM
detects a malfunction, the MI will light up to
inform the driver that a malfunction has been
detected.
Mode II Ignition switch in ON
position
Engine stopped
SELF-DIAGNOSTIC RESULTS This function allows DTCs to be read.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
Malfunction Indicator (MI) (Cont'd)
EC-1034

CONSULT-II
CONSULT-II INSPECTION PROCEDURE
1. Turn ignition switch OFF.
2. Connect CONSULT-II to data link connector, which is located
under the driver side dash panel.
3. Turn ignition switch ON.
4. Touch ªSTARTº.
5. Touch ªENGINEº.
6. Perform each diagnostic test mode according to each service
procedure.
For further information, see the CONSULT-II Operation
Manual.
SAT165K
SEF995X
SEF320Y
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
EC-1038

ENGINE CONTROL COMPONENT PARTS/CONTROL
SYSTEMS APPLICATION
ItemDIAGNOSTIC TEST MODE
SELF-DIAG
RESULTSDATA MONI-
TORACTIVE
TEST
ENGINE CONTROL COMPONENT PARTS
INPUTEngine coolant temperature sensor X X
Vehicle speed sensor X X
Accelerator position sensor X X X
Accelerator position switch X X
Accelerator switch (F/C) X X
Crankshaft position sensor (TDC) X X
Ignition switch (start signal) X
Park/Neutral position (PNP) switch X
Battery voltage X
Air conditioner switch X
Mass air flow sensor X X
Stop lamp switch X X
Heat up switch X
Charge air pressure sensor X
OUTPUTGlow relayXX
EGR volume control valve X X X
Cooling fan relay X X X
Air conditioner relay X
Variable nozzle turbocharger control solenoid valve X
Swirl control valve control solenoid valve X X
Exhaust gas control valve control solenoid valve X
X: Applicable
SELF-DIAGNOSTIC MODE
Regarding items detected in ªSELF-DIAG RESULTSº mode,
refer to ªTROUBLE DIAGNOSIS Ð INDEXº, EC-1006.
DATA MONITOR MODE
Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
CKPSzRPM (TDC)
[rpm]jj+The engine speed computed from the
crankshaft position sensor (TDC) signal
is displayed.
CMPSzRPMzPUMP
[rpm]jj+The engine speed computed from the
pulse signal sent from electronic control
fuel injection pump is displayed.
COOLAN TEMP/S
[ÉC] or [ÉF]
jj+The engine coolant temperature (deter-
mined by the signal voltage of the
engine coolant temperature sensor) is
displayed.+When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine cool-
ant temperature determined by the ECM
is displayed.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
CONSULT-II (Cont'd)
EC-1039

Monitored item
[Unit]ECM
input
signalsMain
signalsDescription Remarks
VHCL SPEED SE
[km/h] or [mph]jj+The vehicle speed computed from the
vehicle speed sensor signal is displayed.
FUEL TEMP SEN
[ÉC] or [ÉF]jj+The fuel temperature (sent from elec-
tronic control fuel injection pump) is dis-
played.
ACCEL POS SEN [V]
jj+The accelerator position sensor signal
voltage is displayed.
FULL ACCEL SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the
accelerator position switch signal.
ACCEL SW (FC)
[OPEN/CLOSE]jj+Indicates [OPEN/CLOSE] condition from
the accelerator switch (FC) signal.
OFF ACCEL SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the
accelerator position switch signal.
SPILL/V [ÉCA]
j+The control position of spill valve (sent
from electronic control fuel injection
pump) is displayed.
BATTERY VOLT [V]
jj+The power supply voltage of ECM is dis-
played.
P/N POSI SW
[ON/OFF]jj+Indicates [ON/OFF] condition from the
park/neutral position switch signal.
START SIGNAL
[ON/OFF]jj+Indicates [ON/OFF] condition from the
starter signal.+After starting the engine, [OFF] is dis-
played regardless of the starter signal.
AIR COND SIG
[ON/OFF]jj+Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
BRAKE SW [ON/OFF]
jj+Indicates [ON/OFF] condition from the
stop lamp switch signal.
IGN SW
[ON/OFF]jj+Indicates [ON/OFF] condition from igni-
tion switch signal.
WARM UP SW
[ON/OFF]j+Indicates [ON/OFF] condition from the
heat up switch signal.
MAS AIR/FL SE [V]
jj+The signal voltage of the mass air flow
sensor is displayed.+When the engine is stopped, a certain
value is indicated.
DECELER F/CUT
[ON/OFF]j+The [ON/OFF] condition from decelera-
tion fuel cut signal (sent from electronic
control fuel injection pump) is displayed.
INJ TIMG C/V [%]
j+The duty ratio of fuel injection timing
control valve (sent from electronic con-
trol fuel injection pump) is displayed.
AIR COND RLY
[ON/OFF]j+Indicates the control condition of the air
conditioner relay (determined by ECM
according to the input signals).
GLOW RLY [ON/OFF]
j+The glow relay control condition (deter-
mined by ECM according to the input
signal) is displayed.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
CONSULT-II (Cont'd)
EC-1040

ACTIVE TEST MODE
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
COOLING FAN+Ignition switch: ON
+Operate the cooling fan at
ªLOWº, ªHIº speed and turn
ªOFFº using CONSULT-II.Cooling fan moves at ªLOWº, ªHIº
speed and stops.+Harness and connector
+Cooling fan motor
+Cooling fan relay
OFF ACCEL PO
SIG+Clears the self-learning fully closed accelerator position, detected by accelerator position sensor, from the
ECM.
GLOW RLY+Ignition switch: ON (Engine
stopped)
+Turn the glow relay ªONº and
ªOFFº using CONSULT-II and
listen to operating sound.Glow relay makes the operating
sound.+Harness and connector
+Glow relay
INJ TIMING*+Engine: Return to the original
trouble condition
+Retard the injection timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.+Electronic control fuel injection
pump
SWIRL CONT S/V1+Ignition switch: ON
+Turn solenoid valve ªONº and
ªOFFº with the CONSULT-II and
listen to operating sound.Solenoid valve makes an operating
sound.+Harness and connector
+Solenoid valve
EGR VOL CONT/V+Ignition switch: ON
+Change EGR volume control
valve opening step using CON-
SULT-II.EGR volume control valve makes
an operating sound.+Harness and connector
+EGR volume control valve
*: When using this item, DTC 0707 ªP7zF/INJ TIMG FBº may be detected. If so, erase it because it is not a malfunction.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
CONSULT-II (Cont'd)
EC-1042

Introduction
The engine has an ECM to control major systems such as fuel
injection control, fuel injection timing control, glow control
system, etc. The ECM accepts input signals from sensors and
instantly drives electronic control fuel injection pump. It is essen-
tial that both input and output signals are proper and stable. At
the same time, it is important that there are no problems such as
vacuum leaks, or other problems with the engine.
It is much more difficult to diagnose a problem that occurs inter-
mittently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this
case, careful checking of suspected circuits may help prevent the
replacement of good parts.
A visual check only may not find the cause of the problems. A
road test with CONSULT-II or a circuit tester connected should
be performed. Follow the ªWork Flowº, EC-1047.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a driveability complaint. The
customer can supply good information about such problems,
especially intermittent ones. Find out what symptoms are present
and under what conditions they occur. A ªDiagnostic Worksheetº
like the example on next page should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electroni-
cally controlled engine vehicle.
DIAGNOSTIC WORKSHEET
There are many operating conditions that lead to the malfunction
of engine components. A good grasp of such conditions can
make troubleshooting faster and more accurate.
In general, each customer feels differently about a problem. It is
important to fully understand the symptoms or conditions for a
customer complaint.
Utilize a diagnostic worksheet like the one shown below in order
to organize all the information for troubleshooting.
SEF858S
SEF233G
SEF234G
SEF907L
TROUBLE DIAGNOSIS Ð INTRODUCTIONZD30DDTi
EC-1045

Work Flow
*1 Refer to MA section (ªChecking
and Replacing Fuel Filter and
Draining Waterº, ªENGINE MAIN-
TENANCEº).
*2 If time data of ªSELF-DIAG
RESULTSº is other than ª0º, per-
form ªTROUBLE DIAGNOSIS
FOR INTERMITTENT INCIDENTº,
EC-1076.*3 If the incident cannot be verified,
perform ªTROUBLE DIAGNOSIS
FOR INTERMITTENT INCIDENTº,
EC-1076.
*4 If the on board diagnostic system
cannot be performed, check main
power supply and ground circuit.Refer to ªTROUBLE DIAGNOSIS
FOR POWER SUPPLYº,
EC-1077.
*5 If malfunctioning part cannot be
detected, perform ªTROUBLE
DIAGNOSIS FOR INTERMIT-
TENT INCIDENTº, EC-1076.
SEF374YB
TROUBLE DIAGNOSIS Ð INTRODUCTIONZD30DDTi
EC-1047

DESCRIPTION FOR WORK FLOW
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using
the ªDIAGNOSTIC WORKSHEETº, EC-1045.
STEP IIBefore confirming the concern, check and write down (print out using CONSULT-II) the DTC, then erase the
DTC. Refer to EC-1032.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-1076.
Study the relationship between the cause, specified by DTC, and the symptom described by the customer. (The
ªSymptom Matrix Chartº will be useful. Refer to EC-1055.) Also check related service bulletins for information.
STEP IIITry to confirm the symptom and under what conditions the incident occurs.
The ªDIAGNOSTIC WORK SHEETº is useful to verify the incident. Connect CONSULT-II to the vehicle in DATA
MONITOR (AUTO TRIG) mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-1076.
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the DTC by driving in (or performing) the ªDTC Confirmation Procedureº. Check and read the DTC
by using CONSULT-II.
During the DTC verification, be sure to connect CONSULT-II to the vehicle in DATA MONITOR (AUTO TRIG)
mode and check real time diagnosis results.
If the incident cannot be verified, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-1076.
In case the ªDTC Confirmation Procedureº is not available, perform the ªOverall Function Checkº instead. The
DTC cannot be displayed by this check, however, this simplified ªcheckº is an effective alternative.
The ªNGº result of the ªOverall Function Checkº 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 XXXX.
If the normal code is indicated, proceed to the Basic Inspection, EC-1049. Then perform inspections according to
the Symptom Matrix Chart. Refer to EC-1055.
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) ªHarness Layoutsº.
Gently shake the related connectors, components or wiring harness with CONSULT-II set in ªDATA MONITOR
(AUTO TRIG)º mode.
Check the voltage of the related ECM terminals or monitor the output data from the related sensors with CON-
SULT-II. Refer to EC-1068 or EC-1065.
The ªDiagnostic Procedureº 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 (ªCir-
cuit Inspectionº, ªHOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENTº).
Repair or replace the malfunction parts.
If the malfunctioning part cannot be detected, perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENTº, EC-1076.
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 ªDTC Confirmation Procedureº and confirm the normal code (DTC No. 0505) is detected. If the inci-
dent 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-1032.)
TROUBLE DIAGNOSIS Ð INTRODUCTIONZD30DDTi
Work Flow (Cont'd)
EC-1048