ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-1373
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EC
If the battery is disconnected, the emission-related diagnostic information will be lost within 24
hours.
The following data are cleared when the ECM memory is erased.
–Diagnostic trouble codes
–Freeze frame data
–Fuel pump learning value
–Others
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
Freeze Frame DataEBS011XA
The ECM records the driving conditions such as calculated load value, engine coolant temperature, engine
speed, vehicle speed and intake manifold pressure at the moment a malfunction is detected.
The data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II. For
details, see EC-1407
.
Only one set of freeze frame data can be stored in the ECM. If freeze frame data is stored in the ECM memory
and another freeze frame data occurs later, the first (original) freeze frame data remains unchanged in the
ECM memory.
Freeze frame data (along with the DTCs) are cleared when the ECM memory is erased. Procedures for clear-
ing the ECM memory are described in EC-1372, "
HOW TO ERASE DTC" .
NATS (Nissan Anti-theft System)EBS011XB
If the security indicator lights up with the ignition switch in
the ON position or "NATS MALFUNCTION" is displayed on
"SELF-DIAG RESULTS" screen, perform self-diagnostic
results mode with CONSULT-II using NATS program card.
Refer to NATS (Nissan Anti-Theft System) in BL section.
Confirm no self-diagnostic results of NATS is displayed
before touching "ERASE" in "SELF-DAIG RESULTS" mode
with CONSULT-II.
When replacing ECM, initialization of NATS system and reg-
istration 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 procedure of NATS initialization and NATS ignition key ID registration, refer to CON-
SULT-II operation manual, NATS.
Malfunction Indicator (MI)EBS01F88
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 EC-1699, "MI & DATA LINK
CONNECTORS" .
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.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following three functions.
SEF543X
SAT652J
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-1375
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EC
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
1. Set ECM in Diagnostic Test Mode II (Self-diagnostic results). Refer to EC-1374, "How to Set Diagnostic
Test Mode II (Self-diagnostic Results)" .
2. Fully depress the accelerator pedal and keep it for more than 10 seconds.
The emission-related diagnostic information has been erased from the backup memory in the ECM.
3. Fully release the accelerator pedal, and confirm the DTC 0000 is displayed.
DIAGNOSTIC TEST MODE I — BULB CHECK
In this mode, the MI on the instrument panel should stay ON. If it remains OFF, check the bulb. Refer to EC-
1699, "MI & DATA LINK CONNECTORS" .
DIAGNOSTIC TEST MODE I — MALFUNCTION WARNING
These DTC numbers are clarified in Diagnostic Test Mode II (SELF-DIAGNOSTIC RESULTS)
DIAGNOSTIC TEST MODE II — SELF-DIAGNOSTIC RESULTS
In this mode, the DTC is indicated by the number of blinks of the MI as shown below. A DTC will be used as an
example for how to read a code.
A particular trouble code can be identified by the number of four-digit numeral flashes. The “zero” is indicated
by the number of ten flashes. The length of time the 1,000th-digit numeral flashes on and off is 1.2 seconds
consisting of an ON (0.6-second) - OFF (0.6-second) cycle.
The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later
numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-1351, "
INDEX FOR DTC" )
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to EC-
1375, "How to Erase Diagnostic Test Mode II (Self-diagnostic Results)" .
If the battery 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.
MI Condition
ON When the malfunction is detected.
OFF No malfunction.
PBIA3905E
EC-1376
[YD (WITHOUT EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Relationship Between MI, DTC, CONSULT-II and Driving PatternsEBS01F89
*1: When a malfunction is detected, MI
will light up.*2: MI will not light up after ignition
switch is turned OFF.*3: When a malfunction is detected for
the first time, the DTC will be stored
in ECM.
*4: Other screens except SELF-DIAG-
NOSTIC RESULTS & DATA MONI-
TOR (AUTO TRIG) cannot display
the malfunction. DATA MONITOR
(AUTO TRIG) can display the mal-
function at the moment it is detected.*5: The DTC will not be displayed any
longer after vehicle is driven 40 times
(Driving pattern A) without the same
malfunction. (The DTC still remain in
ECM.)
MBIB0622E
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-1377
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EC
DRIVING PATTERN A
The counter will be cleared when the malfunction is detected regardless of (1) - (4).
The counter will be counted up when (1) - (4) are satisfied without the same malfunction.
The DTC will not be displayed after the counter reaches 40.
MBIB0923E
EC-1380
[YD (WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
Description for Work Flow
DIAGNOSTIC WORK SHEET
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about an incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one shown below in order to
organize all the information for troubleshooting.
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using the
EC-1380, "
DIAGNOSTIC WORK SHEET" .
STEP IIBefore confirming the concern, check and write down (print out using CONSULT-II) the DTC and the freeze frame
data, then erase the DTC. The DTC and the freeze frame data can be used when duplicating the incident at STEP III
& IV. Refer to EC-1373
.
If the incident cannot be verified, perform EC-1414, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Study the relationship between the cause, specified by DTC, and the symptom described by the customer. (The
Symptom Matrix Chart will be useful. Refer toEC-1387
) Also check related service bulletins for information.
STEP IIITry to confirm the symptom and under what conditions the incident occurs.
The DIAGNOSTIC WORK SHEET and the freeze frame data are 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 EC-1414, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
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 DTC Confirmation Procedure. Check and read the DTC and the
freeze frame data 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 EC-1414, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
In case the DTC Confirmation Procedure is not available, perform the Overall Function Check instead. The DTC can-
not 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 PXXXX.
If the normal code is indicated, proceed to the Basic Inspection, EC-1382
. Then perform inspections according to the
Symptom Matrix Chart. Refer to EC-1387
.
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-II 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 CONSULT-II.
Refer to EC-1398
or EC-1411 .
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-23, "
How to Per-
form Efficient Diagnosis for an Electrical Incident" , “Circuit Inspection”.
Repair or replace the malfunction parts.
If the malfunctioning part cannot be detected, perform EC-1414, "
TROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENT" .
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 (DTC P0000) 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-1372
.)
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TROUBLE DIAGNOSIS
EC-1381
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EC
Worksheet Sample
DTC Inspection Priority ChartEBS012AT
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000. Refer to
EC-1425, "
DTC U1000 CAN COMMUNICATION LINE" .
MTBL0533
TROUBLE DIAGNOSIS
EC-1407
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EC
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
X: Applicable
SELF-DIAGNOSTIC MODE
Self Diagnostic Item
Regarding items detected in “SELF-DIAG RESULTS” mode, refer to EC-1351, "INDEX FOR DTC" .
Freeze Frame Data
ItemDIAGNOSTIC TEST MODE
SELF-DIAG RESULTS
DATA MON-
ITORACTIVE
TEST
DTCFREEZE
FRAME
DATA
ENGINE CONTROL COMPONENT PARTS
INPUTCrankshaft position sensor×××
Camshaft position sensor×
Engine coolant temperature sensor××××
Vehicle speed sensor×××
Fuel pump temperature sensor××
Accelerator pedal position sensor 1××
Accelerator pedal position sensor 2××
Fuel rail pressure sensor××
Mass air flow sensor××
Intake air temperature sensor×
Turbocharger boost sensor×××
Battery voltage××
Park/neutral position (PNP) switch×
Power steering pressure switch×
Stop lamp switch×
Barometric pressure sensor (built-into ECM)××
Fuel injector adjustment resistor×
ASCD steering switch××
ASCD brake switch××
ASCD clutch switch××
OUTPUTFuel pump×××
Fuel injector×××
Glow relay××
Cooling fan relay×××
EGR volume control valve××
Freeze frame data item Description
DIAG TROUBLE CODE
[PXXXX]
The engine control component part/control system has a trouble code, it is displayed as “PXXXX”.
(Refer to EC-1351, "
INDEX FOR DTC" .)
CAL/LD VALUE [%]
The calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP [°C] or
[°F]
The engine coolant temperature at the moment a malfunction is detected is displayed.
ENGINE SPEED [rpm]
The engine speed at the moment a malfunction is detected is displayed.
VEHICL SPEED [km/h] or
[mph]
The vehicle speed at the moment a malfunction is detected is displayed.
INT MANI PRES [kPa]
The intake manifold pressure at the moment a malfunction is detected is displayed.
EC-1408
[YD (WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
DATA MONITOR MODE
MONITOR ITEMECM
INPUT
SIGNALMAIN
SIG-
NALSCONDITION SPECIFICATION
CKPS·RPM (TDC) [rpm]××
The engine speed computed from the
crankshaft position sensor signal is dis-
played.
COOLAN TEMP/S
[°C] or [°F]××
The engine coolant temperature (deter-
mined by the signal voltage of the engine
coolant temperature sensor) is displayed.When the engine coolant temper-
ature circuit is open or short, ECM
enters fail-safe mode. The engine
coolant temperature determined
by the ECM is displayed.
VHCL SPEED SE
[km/h] or [mph]××
The vehicle speed computed form the
vehicle speed sensor signal is displayed.
FUEL TEMP SEN
[°C] or [°F]××
The fuel temperature (determined by the
signal voltage of the fuel pump tempera-
ture sensor) is displayed.
ACCEL POS SEN [V]××
The accelerator pedal position sensor 1
signal voltage is displayed.These signals are converted by
ECM internally. Thus, they differ
from ECM terminals voltage.
ACCEL SEN 2 [V]××
The accelerator pedal position sensor 2
signal voltage is displayed.
ACT CR PRESS [MPa]××
The Fuel rail pressure (determined by the
signal voltage of the fuel rail pressure
sensor) is displayed.
BATTERY VOLT [V]××
The power supply voltage of ECM is dis-
played.
P/N POSI SW [ON/OFF]××
Indicates [ON/OFF] condition from the
park/neutral position switch signal.
START SIGNAL [ON/OFF]××
indicates [ON/OFF] condition from the
starter signal.
PW/ST SIGNAL [ON/OFF]×
indicates [ON/OFF] condition from the
power steering pressure switch signal.
BRAKE SW [ON/OFF]××
indicates [ON/OFF] condition from the
stop lamp switch signal.
BRAKE SW2 [ON/OFF]××
indicates [ON/OFF] condition from the
ASCD brake switch and ASCD clutch
switch signal.
IGN SW [ON/OFF]××
Indicates [ON/OFF] condition from igni-
tion switch signal.
MAS AIR/FL SE [V]××
The signal voltage of the mass air flow
sensor is displayed.
MAIN INJ WID [msec]×
Indicates the actual fuel injection pulse
width compensated by ECM according to
the input signals.
PUMP CURRENT [mA]×
Indicates the fuel pump power supply
current from the ECM.
GLOW RLY [ON/OFF]×
The glow relay control condition (deter-
mined by ECM according to the input sig-
nal) is displayed.
COOLING FAN
[LOW/HI/OFF]×
Indicates the control condition of the
cooling fans (determined by ECM
according to the input signal).
LOW ... Operates at low speed.
HI ... Operates at high speed.
OFF ... Stopped