2000 NISSAN PATROL Electronic Repair Manual

DTC and MI Detection Logic
When a malfunction is detected, the malfunction (DTC) is stored in the ECM memory.
The MI will light up each time the ECM detects malfunction. For diagnostic items causing the MI to light up,
refer to ªTROUBLE DIAGNOSIS Ð INDEXº, EC-1006.
Diagnostic Trouble Code (DTC)
HOW TO READ DTC
The DTC can be read by the following methods.
Without CONSULT-II
ECM displays the DTC by a set of four digit numbers with MI illumination in the diagnostic test mode II
(Self-diagnostic results). Example: 0102, 0407, 1004, etc.
With CONSULT-II
CONSULT-II displays the DTC in ªSELF-DIAG RESULTSº mode. Examples: ªCRANK POS SEN (TDC)º, etc.
+Output of the trouble code means that the indicated circuit has a malfunction. However, in the
Mode II it does not indicate whether the malfunction is still occurring or occurred in the past and
returned to normal.
CONSULT-II can identify them. Therefore, using CONSULT-II (if available) is recommended.
HOW TO ERASE DTC
How to erase DTC (
With CONSULT-II)
1.If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
5 seconds and then turn it ªONº (engine stopped) again.
2. Touch ªENGINEº.
3. Touch ªSELF-DIAG RESULTSº.
4. Touch ªERASEº. (The DTC in the ECM will be erased.)
The emission related diagnostic information in the ECM can be erased by selecting ªERASEº in the ªSELF-
DIAG RESULTSº mode with CONSULT-II.
How to erase DTC (Without CONSULT-II)
1.If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
5 seconds and then turn it ªONº (engine stopped) again.
SEF371Y
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
EC-1032

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

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

How to switch diagnostic test modes
*1: EC-1276 *2: EC-1034 *3: EC-1276
SEF372YB
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
Malfunction Indicator (MI) (Cont'd)
EC-1035

Diagnostic test mode I Ð Bulb check
In this mode, the MI on the instrument panel should stay ON. If it remains OFF, check the bulb. Refer to EL
section, ªWARNING LAMPS AND CHIMEº or see EC-1276.
Diagnostic test mode I Ð Malfunction warning
MI Condition
ON When the malfunction is detected or the ECM's CPU is malfunctioning.
OFF No malfunction.
Diagnostic test mode II Ð Self-diagnostic results
In this mode, DTC is indicated by the number of blinks of the MI as shown below.
Long (0.6 second) blinking indicates the two LH digits of number and short (0.3 second) blinking indicates
the two RH digits of number. For example, the MI blinks 10 times for 6 seconds (0.6 sec x 10 times) and
then it blinks three times for about 1 second (0.3 sec x 3 times). This indicates the DTC ª1003º.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC ª0505º refers to no
malfunction. (See TROUBLE DIAGNOSIS Ð INDEX, EC-1006.)
How to erase diagnostic test mode II (Self-diagnostic results)
The DTC can be erased from the backup memory in the ECM when the diagnostic test mode is changed
from Diagnostic Test Mode II to Diagnostic Test Mode I. (Refer to ªHow to Switch Diagnostic Test Modesº,
EC-1035.)
+If the battery terminal is disconnected, the DTC will be lost from the backup memory within 24
hours.
+Be careful not to erase the stored memory before starting trouble diagnoses.
SEF298QA
SEF162PB
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONZD30DDTi
Malfunction Indicator (MI) (Cont'd)
EC-1036

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

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