2000 NISSAN PATROL ECU

2. Change the diagnostic test mode from Mode II to Mode I by using the data link connector. (See
EC-1035.)
The emission related diagnostic information in the ECM can be erased by changing the diagnostic test mode.
+If the battery is disconnected, the emission-related diagnostic information will be lost after
approx. 24 hours.
+Erasing the emission-related diagnostic information using CONSULT-II is easier and quicker than
switching the diagnostic test mode using the data link connector.
NATS (Nissan Anti-Theft System)
+If the security indicator lights up with the ignition switch
in the ªONº position or ªNATS MALFUNCTIONº is dis-
played on ªSELF-DIAG RESULTSº screen, perform self-
diagnostic results mode with CONSULT-II using NATS
program card. Refer to ªNATS (Nissan Anti-Theft Sys-
tem)º in EL section.
+Confirm no self-diagnostic results of NATS is displayed
before touching ªERASEº in ªSELF-DIAG RESULTSº
mode with CONSULT-II.
+When replacing ECM, initialization of NATS system and
registration of all NATS ignition key IDs must be carried
out with CONSULT-II using NATS program card.
Therefore, be sure to receive all keys from vehicle
owner. Regarding the procedures of NATS initialization
and NATS ignition key ID registration, refer to CON-
SULT-II operation manual, NATS.
Malfunction Indicator (MI)
DESCRIPTION
The MI is located on the instrument panel.
1. The MI will light up when the ignition switch is turned ON
without the engine running. This is a bulb check.
+If the MI does not light up, refer to EL section (ªWARNING
LAMPS AND CHIMEº) or see EC-1276.
2. When the engine is started, the MI should go off.
If the MI remains on, the on board diagnostic system has
detected an engine system malfunction.
If MI illuminates or blinks irregularly after starting engine,
water may have accumulated in fuel filter. Drain water from
fuel filter. Refer to MA section.
SEF252Z
SAT652J
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
Diagnostic Trouble Code (DTC) (Cont'd)
EC-1033

Relationship between MI, DTC, CONSULT-II and driving patterns
*1: When a malfunction is detected,
MI will light up.
*2: When the same malfunction is
detected in two consecutive driv-
ing patterns, MI will stay lit up.
*3: MI will go off after vehicle is
driven three times without any
malfunctions.*4: When a malfunction is detected
for the first time, the DTC will be
stored in ECM.
*5: The DTC will not be displayed any
longer after vehicle is driven 40
times without the same malfunc-
tion. (The DTC still remain in
ECM.)*6: Other screens except SELF-DI-
AGNOSTIC RESULTS & DATA
MONITOR (AUTO TRIG) cannot
display the malfunction. DATA
MONITOR (AUTO TRIG) can dis-
play the malfunction at the
moment it is detected.
SEF659SC
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
Malfunction Indicator (MI) (Cont'd)
EC-1037

ECM Terminals and Reference Value
PREPARATION
1. ECM is located behind the instrument lower panel. For this
inspection, remove the driver's side instrument lower cover.
2. Remove ECM harness protector.
3. Perform all voltage measurements with the connector con-
nected. Extend tester probe as shown to perform tests eas-
ily.
+Open harness securing clip to make testing easier.
+Use extreme care not to touch 2 pins at one time.
+Data is for comparison and may not be exact.
Be sure ECM unit is properly grounded before checking.
SEF519VA
AEC913
SEF367I
SEF665S
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
EC-1068

Description
Intermittent incidents (I/I) may occur. In many cases, the problem resolves itself (the part or circuit function
returns to normal without intervention). It is important to realize that the symptoms described in the custom-
er's complaint often do not recur on DTC visits. Realize also that the most frequent cause of I/I occurrences
is poor electrical connections. Because of this, the conditions under which the incident occurred may not be
clear. Therefore, circuit checks made as part of the standard diagnostic procedure may not indicate the
specific problem area.
COMMON I/I REPORT SITUATIONS
STEP in Work Flow Situation
II The CONSULT-II is used. The SELF-DIAG RESULTS screen shows time data other than ª0º.
III The symptom described by the customer does not recur.
IV DTC does not appear during the DTC Confirmation Procedure.
VI The Diagnostic Procedure for XXXX does not indicate the problem area.
Diagnostic Procedure
1 INSPECTION START
Erase DTCs. Refer to ªHOW TO ERASE DTCº, EC-1032.
cGO TO 2.
2 CHECK GROUND TERMINALS
Check ground terminals for corroding or loose connection.
Refer to GI section (ªGROUND INSPECTIONº, ªCircuit Inspectionº).
OK or NG
OKcGO TO 3.
NGcRepair or replace.
3 SEARCH FOR ELECTRICAL INCIDENT
Perform GI section, ªIncident Simulation Testsº.
OK or NG
OKcINSPECTION END
NGcRepair or replace.
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTZD30DDTi
EC-1076

System Description
NATS has the following immobilizer functions:
+Since only NATS ignition keys, whose ID nos. have been registered into the ECM and IMMU of NATS,
allow the engine to run, operation of a stolen vehicle without a NATS registered key is prevented by
NATS.
That is to say, NATS will immobilize the engine if someone tries to start it without the registered key of
NATS.
+This version of NATS has dongle unit to improve its anti-theft performance (RHD models). Dongle unit
has its own ID which is registered into NATS IMMU. So it dongle unit is replaced, initialization must be
carried out.
+When malfunction of dongle unit is detected:
Ð The security indicator lamp illuminates for about 15 minutes after ignition switch is turned to ON.
Ð When dongle unit has a malfunction and the indicator lamp is illuminated, engine can not be started.
However, engine can be started only one time when security indicator turns off in about 15 minutes
after ignition switch is turned to ON.
+Both of the originally supplied ignition key IDs have been NATS registered.
If requested by the vehicle owner, a maximum of five key IDs can be registered into the NATS compo-
nents.
+The NATS security indicator (NATS security ind.) blinks when the ignition switch is in ªOFFº or ªACCº
position. Therefore, NATS warns outsiders that the vehicle is equipped with the anti-theft system.
+When NATS detects trouble, the security indicator lamp lights up as follows.
Condition
IGN ON andWith Dongle Without Dongle
MIL Security Indicator MIL Security Indicator
NATS malfunction
(except dongle unit) is
detectedÐ1. 6 times blinking
2. Staying ON after igni-
tion switch is turned
ONÐ Staying ON
Only malfunction of
dongle unit is detected.ÐStaying ONfor about
15 minutesafter ignition
switch is turned ON.ÐÐ
Malfunction of NATS
and engine related parts
are detectedStaying ON1. 6 times blinking
2. Staying ON after igni-
tion switch is turned
ONStaying ON Staying ON
Only engine related part
malfunction is detectedStaying ON Ð Staying ON Ð
Just after initialization of
NATSÐ 6 times blinking Ð Ð
+NATS trouble diagnoses, system initialization and additional registration of other NATS ignition key IDs
must be carried out using CONSULT-II hardware and CONSULT-II NATS software.
Regarding the procedures of NATS initialization and NATS ignition key ID registration, refer to CON-
SULT-II operation manual, NATS.
+When servicing a malfunction of the NATS (indicated by lighting up of security Indicator Lamp)
or registering another NATS ignition key ID no., it is necessary to re-register original key identi-
fication. Therefore, be sure to receive ALL KEYS from vehicle owner.
NATS (Nissan Anti-Theft System)
EL-1164

System Composition
The immobilizer function of the NATS consists of the following:
+NATS ignition key
+NATS immobilizer control unit (NATS IMMU), located in the ignition key cylinder
+Engine control module (ECM)
+Dongle unit (RHD models)
+NATS security indicator
SEL148XA
NATS (Nissan Anti-Theft System)
EL-1165

CONSULT-II DIAGNOSTIC TEST MODE FUNCTION
CONSULT-II DIAGNOSTIC TEST
MODEDescription
C/U INITIALIZATION When replacing any of the following components, C/U initialization is necessary.
[NATS ignition key/IMMU/ECM/Dongle unit]
SELF-DIAG RESULTS Detected items (screen terms) are as shown in the chart below.
NOTE:
When any initialization is performed, all ID previously registered will be erased. So all NATS ignition
keys must be registered again.
The engine cannot be started with an unregistered key. In this case, the system may show ªDIFFER-
ENCE OF KEYº or ªLOCK MODEº as a self-diagnostic result on the CONSULT-II screen.
When initialization is performed (for RHD models), security indicator will flash six times to demon-
strate recognition of dongle unit ID.
HOW TO READ SELF-DIAGNOSTIC RESULTS
SEL151X
NATS (Nissan Anti-Theft System)
CONSULT-II (Cont'd)
EL-1170

SELF-DIAGNOSTIC RESULTS ITEM CHART
Detected items (Screen terms) Description Reference page
ECM INT CIRC-IMMUThe malfunction of ECM internal circuit of IMMU communication line is
detected.EL-1175
CHAIN OF ECM-IMMUCommunication impossible between ECM and IMMU.
(In rare case, ªCHAIN OF ECM-IMMUº might be stored during key regis-
tration procedure, even if the system is not malfunctioning.)EL-1176
DIFFERENCE OF KEYIMMU can receive the key ID signal but the result of ID verification
between key ID and IMMU is NG.EL-1178
CHAIN OF IMMU-KEYIMMU cannot receive the key ID signal. Otherwise, the registered ID sig-
nal from dongle unit cannot be received when the IMMU requests the
ID.EL-1179
ID DISCORD, IMM-ECMThe result of ID verification between IMMU and ECM is NG. System ini-
tialization is required.EL-1180
DON'T ERASE BEFORE CHECK-
ING ENG DIAGEngine trouble data and NATS trouble data have been detected in ECM. EL-1172
LOCK MODEWhen the starting operation is carried out 5 or more times consecutively
under the following conditions, NATS will shift the mode to one which
prevents the engine from being started.
+unregistered ignition key is used
+IMMU or ECM malfunctioningEL-1181
NATS (Nissan Anti-Theft System)
CONSULT-II (Cont'd)
EL-1171