ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-47
[QR25(WITH EURO-OBD)]
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EC
*2: These numbers are prescribed by ISO 15031-5.
*3: In Diagnostic Test Mode II (Self-diagnostic results), these numbers are controlled by NISSAN.
*4: These are not displayed with GST.
*5: For A/T models.
*6: The trouble shooting for this DTC needs CONSULT-II.
*7: When the fail-safe operations for both self-diagnoses occur at the same time, the MI illuminates.
DTC AND 1ST TRIP DTC
The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, the 1st trip
DTC will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory. The MI will not
light up (two trip detection logic). If the same malfunction is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MI lights up. In other words,
the DTC is stored in the ECM memory and the MI lights up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or light up the MI during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in EC-56, "
HOW
TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION" .
For malfunctions in which 1st trip DTCs are displayed, refer to EC-45
. These items are required by legal reg-
ulations to continuously monitor the system/component. In addition, the items monitored non-continuously are
also displayed on CONSULT-II.
1st trip DTC is specified in Mode 7 of ISO 15031-5. 1st trip DTC detection occurs without lighting up the MI
and therefore does not warn the driver of a an incident. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in “Work Flow” procedure Step II, refer to EC-68
. Then perform “DTC Confirmation Proce-
dure” or “Overall Function Check” to try to duplicate the malfunction. If the malfunction is duplicated, the item
requires repair.
How to Read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.
With CONSULT-II
With GST
CONSULT-II or GST (Generic Scan Tool) Examples: P0340, P0705, P0750, etc.
These DTCs are prescribed by ISO 15031-5.
(CONSULT-II also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MI in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0102, 0340 etc.
These DTCs are controlled by NISSAN.
●1st trip DTC No. is the same as DTC No.
●Output of a DTC indicates a malfunction. However, GST or the Diagnostic Test Mode II do not indi-
cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-II can identify malfunction status as shown below. Therefore, using CONSULT-II (if
available) is recommended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown below. DTC or 1st trip DTC of a malfunc-
tion is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-II. Time data indicates how many times
the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be “0”.
EC-52
[QR25(WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
How to Display SRT Code
WITH CONSULT-II
Selecting “SRT STATUS” in “DTC CONFIRMATION” mode with
CONSULT-II.
For items whose SRT codes are set, a “CMPLT” is displayed on the
CONSULT-II screen; for items whose SRT codes are not set,
“INCMP” is displayed.
A sample of CONSULT-II display for SRT code is shown at right.
“INCMP” means the self-diagnosis is incomplete and SRT is not set.
“CMPLT” means the self-diagnosis is complete and SRT is set.
WITH GST
Selecting Mode 1 with GST (Generic Scan Tool)
*1EC-47*2EC-52*3EC-50
SEF573XB
PBIB0666E
EC-436
[QR25(WITHOUT EURO-OBD)]
PRECAUTIONS
●Do not disassemble ECM.
●If a battery terminal is disconnected, the memory will return
to the ECM value.
The ECM will now start to self-control at its initial value.
Engine operation can vary slightly when the terminal is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.
●When connecting ECM harness connector, fasten it
securely with a lever as far as it will go as shown at right.
●When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminal, when connecting pin connectors.
●Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge)
voltage to develop in coil and condenser, thus resulting in
damage to ICs.
●Keep engine control system harness at least 10 cm (4 in)
away from adjacent harness, to prevent engine control sys-
tem malfunctions due to receiving external noise, degraded
operation of ICs, etc.
●Keep engine control system parts and harness dry.
●Before replacing ECM, perform “ECM Terminals and Refer-
ence Value” inspection and make sure ECM functions prop-
erly. Refer to EC-479
.
●Handle mass air flow sensor carefully to avoid damage.
●Do not disassemble mass air flow sensor.
●Do not clean mass air flow sensor with any type of deter-
gent.
●Do not disassemble electric throttle control actuator.
●Even a slight leak in the air intake system can cause seri-
ous incidents.
●Do not shock or jar the camshaft position sensor (PHASE),
crankshaft position sensor (POS).
SEF707Y
SEF908W
PBIB0090E
MEF040D
EC-462
[QR25(WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
Description for Work Flow
DIAGNOSTIC WORKSHEET
Description
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 on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MI to come on steady or blink and
DTC to be detected. Examples:
●Vehicle ran out of fuel, which caused the engine to misfire.
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using the
“DIAGNOSTIC WORK SHEET”, EC-462
.
STEP IIBefore confirming the concern, check and write down (print out using CONSULT-II or GST) the (1st trip) DTC and the
(1st trip) freeze frame data, then erase the DTC and the data. (Refer to EC-455
.) The (1st trip) DTC and the (1st trip)
freeze frame data can be used when duplicating the incident at STEP III & IV.
If the incident cannot be verified, perform EC-506, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Study the relationship between the cause, specified by (1st trip) DTC, and the symptom described by the customer.
(The “Symptom Matrix Chart” will be useful. See EC-469
.)
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-506, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the (1st trip) DTC by driving in (or performing) the “DTC Confirmation Procedure”. Check and read the
(1st trip) DTC and (1st trip) freeze frame data by using CONSULT-II or GST.
During the (1st trip) 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-506, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
In case the “DTC Confirmation Procedure” is not available, perform the “Overall Function Check” instead. The (1st
trip) 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 (1st trip) 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. (Refer to EC-465
.) Then perform inspections
according to the Symptom Matrix Chart. (Refer to EC-469
.)
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-479
, EC-496 .
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 “Circuit Inspection” in
GI-23, "
How to Perform Efficient Diagnosis for an Electrical Incident" .
Repair or replace the malfunction parts.
If malfunctioning part cannot be detected, perform EC-506, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT" .
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 No. P0000] is detected. If the incident
is still detected in the final check, perform STEP VI by using a method different from the previous one.
Before returning the vehicle to the customer, be sure to erase the unnecessary (already fixed) (1st trip) DTC in ECM.
(Refer to EC-455, "
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION" .)
SEF907L
EC-470
[QR25(WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)Air Positive crankcase ventilation sys-
tem334444444 41EC-1389
Incorrect idle speed adjustment 33 1111 1EC-465
Electric throttle control actuator 112332222 2 2EC-1273
,
EC-1275
,
EC-1281
IgnitionIncorrect ignition timing adjustment33111 11 1EC-465
Ignition circuit 11222 22 2EC-1331
Main power supply and ground circuit 22333 33 23EC-1193
Mass air flow sensor circuit 11222 22 2EC-1202
Engine coolant temperature sensor circuit 11222322312EC-1209
Throttle position sensor circuit 12 22222 2EC-1214
Accelerator pedal position sensor circuit3212 2EC-1222
Heated oxygen sensor 1 circuit 1232 22 2EC-1229,
EC-671
Knock sensor circuit 2 2 3EC-1235
Crankshaft position sensor (POS) circuit 2 2EC-1240
Camshaft position sensor (PHASE) circuit 2 2EC-1246
Vehicle speed signal circuit 2 3 3 3EC-1252
Power steering pressure sensor circuit 2 3333EC-1257
ECM 22333333333EC-1262,
EC-1269
Intake valve timing control solenoid valve cir-
cuit332 13223 3EC-699
VIAS control solenoid valve circuit 1EC-714
PNP switch circuit 3 3 3 3 3 3 3EC-705
Start signal circuit 2EC-1362
Refrigerant pressure sensor circuit 2 3333 4EC-1373
Electrical load signal circuit3333EC-1377
Air conditioner circuit 223333333 3 2AT C - 3 3
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)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
TROUBLE DIAGNOSIS
EC-471
[QR25(WITHOUT EURO-OBD)]
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EC
SYSTEM — ENGINE MECHANICAL & OTHER
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)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank
5
5FL-9
Fuel piping 5 5 5 5 5 5FL-3,EM-
32
Vapor lock—
Valve deposit
555555 5—
Poor fuel (Heavy weight gaso-
line, Low octane)—
Air Air duct
55555 5EM-14
Air cleanerEM-14
Air leakage from air duct
(Mass air flow sensor —electric
throttle control actuator)
5555EM-14
Electric throttle control actuatorEM-16
Air leakage from intake manifold/
Collector/GasketEM-16
Cranking Battery
111111 11SC-3
Alternator circuitSC-12
Starter circuit 3SC-20
Signal plate 6EM-73
PNP switch
4MT-12 or
AT-349
Engine Cylinder head
55555 55 5EM-59
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-73
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nismTiming chain
55555 55 5EM-37
CamshaftEM-46
Intake valve
3EM-59
Exhaust valve
EC-472
[QR25(WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-24
,EX-
2Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 52EM-26
,LU-
9 , LU-10 ,
LU-13
Oil level (Low)/Filthy oilLU-7
Cooling Radiator/Hose/Radiator filler cap
55555 55 25CO-11
Thermostat 5CO-20
Water pumpCO-18
Water galleryCO-7
Cooling fan 5CO-11
Coolant level (low)/Contaminated
coolantCO-9
NATS (Nissan Anti-theft System) 1 1EC-456 or
BL-80
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)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
TROUBLE DIAGNOSIS
EC-473
[QR25(WITHOUT EURO-OBD)]
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EC
Engine Control Component Parts LocationEBS00NEE
PBIB1443E