TROUBLE DIAGNOSIS
EC-407
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TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionEBS00BMU
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. 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 vac-
uum leaks, fouled spark plugs, or other problems with the engine.
It is much more difficult to diagnose a problem that occurs intermit-
tently 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 replace-
ment of good parts.
A visual check only may not find the cause of the problems. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the “Work Flow” onEC-408
.
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such problems, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple onEC-410
should be used.
Start your diagnosis by looking for “conventional” problems first. This
will help troubleshoot driveability problems on an electronically con-
trolled engine vehicle.
MEF036D
SEF233G
SEF234G
TROUBLE DIAGNOSIS
EC-409
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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 a problem. 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:
lVehicle 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-409
.
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 toEC-402
.) 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, performEC-453, "
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. SeeEC-417
.)
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, performEC-453, "
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, performEC-453, "
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 toEC-412
.) Then perform inspections
according to the Symptom Matrix Chart. (Refer toEC-417
.)
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 toEC-427
,EC-443.
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-24, "
How to Perform Efficient Diagnosis for an Electrical Incident".
Repair or replace the malfunction parts.
If malfunctioning part cannot be detected, performEC-453, "
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 toEC-402, "
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION".)
SEF907L
TROUBLE DIAGNOSIS
EC-411
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EC
Fail-safe ChartEBS00BMW
The ECM enters fail-safe mode, if any of the following malfunctions is detected due to the open or short circuit.
When the ECM enters the fail-safe mode, the MI illuminates.
Priority Detected items (DTC)
1
lU1000 CAN communication line
lP0102 P0103 Mass air flow sensor
lP0117 P0118 Engine coolant temperature sensor
lP0120 Throttle position sensor
lP0121 Accelerator pedal position sensor
lP0327 P0328 Knock sensor
lP0335 Crankshaft position sensor (POS)
lP0340 Camshaft position sensor (PHASE)
lP0500 Vehicle speed sensor
lP0605 ECM
2
lP0134 Heated oxygen sensor 1
lP0550 Power steering pressure sensor
lP0650 MI
lP1065 ECM power supply
lP1122 Electric throttle control function
lP1123 Throttle control motor relay
lP1212 ESP/TCS/ABS communication line
lP1805 Brake switch
3
lP1121 Electric throttle control actuator
lP1217 Engine over temperature (OVERHEAT)
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning
ignition switch “ON” or “START”.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided (CONSULT-
II display)
Just as ignition switch is turned
ON or Start40°C (104°F)
More than approx. 4 minutes after
ignition ON or Start80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cool-
ing fan operates while engine is running.
P0120 Throttle position sensor cir-
cuitECM controls the electric throttle control actuator by regulating the throttle opening to
small range.
Therefore, acceleration will be poor.
Condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration
EC-414
[QR (WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
6.PERFORM IDLE AIR VOLUME LEARNING
Refer toEC-396, "
Idle Air Volume Learning".
CMPLT or INCMP
CMPLT>>GOTO7.
INCMP >> 1. Follow the construction of “Idle Air Volume Learning”.
2. GO TO 4.
7.CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8.DETECT MALFUNCTIONING PART
Check the Following.
lCheck camshaft position sensor (PHASE) and circuit. Refer toEC-507.
lCheck crankshaft position sensor (POS) and circuit. Refer toEC-501.
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace.
2. GO TO 4.
9.CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of a problem, but
this is the rarely the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer toEC-403, "
NATS
(Nissan Anti-theft System)".
>> GO TO 4. Which is the result CMPLT or INCMP
M/T: 650±50 rpm
A/T: 700±50 rpm (in "P" or "N" position)
M/T: 650±50 rpm
A/T: 700±50 rpm (in "P" or "N" position)
EC-416
[QR (WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
15.CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
OK or NG
OK >>INSPECTION END
NG >> GO TO 16.
16.CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer toEM-43, "
TIMING CHAIN".
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation.
2. GO TO 4.
17.DETECT MALFUNCTIONING PART
Check the following.
lCheck camshaft position sensor (PHASE) and circuit. Refer toEC-507.
lCheck crankshaft position sensor (POS) and circuit. Refer toEC-501.
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace.
2. GO TO 4.
18.CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of a problem, but
this is the rarely the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer toEC-403, "
NATS
(Nissan Anti-theft System)".
>> GO TO 4. M/T: 14±5°BTDC
A/T: 16±5°BTDC (in "P" or "N" position)
TROUBLE DIAGNOSIS
EC-417
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Symptom Matrix ChartEBS00BMY
SYSTEM — BASIC ENGINE CONTROL SYSTEM
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 pump circuit 1 1 2 3 2 2 2 3 2EC-627
Fuel pressure regulator system 3 3 4 4 4 4 4 4 4 4EC-399
Injector circuit 1 1 2 3 2 2 2 2EC-618
Evaporativeemissionsystem 334444444 4EC-647
Air Positive crankcase ventilation sys-
tem334444444 41EC-650
Incorrect idle speed adjustment 3 3 1 1 1 1 1EC-412
Electric throttle control actuator 1 1 2 3 3 2 2 2 2 2 2EC-534
,
EC-536
,
EC-542
Ignition Incorrect ignition timing adjustment 3 3 1 1 1 1 1 1EC-412
Ignition circuit 1 1 2 2 2 2 2 2EC-592
Main power supply and ground circuit 2 2 3 3 3 3 3 2 3EC-454
Mass air flow sensor circuit 1 1 2 2 2 2 2 2EC-463
Engine coolant temperature sensor circuit 1 1 2 2 2 3 2 2 3 1 2EC-470
Throttle position sensor circuit 1 2 2 2 2 2 2 2EC-475
Accelerator pedal position sensor circuit 3 2 1 2 2EC-484
Heated oxygen sensor 1 circuit 1 2 3 2 2 2 2EC-490,
EC-581
Knock sensor circuit 2 2 3EC-496
Crankshaft position sensor (POS) circuit 2 2EC-501
Camshaft position sensor (PHASE) circuit 2 2EC-507
Vehicle speed signal circuit 2 3 3 3EC-513
Power steering pressure sensor circuit 2 3 3 3 3EC-518
ECM 22333333333EC-523,
EC-530
Intake valve timing control solenoid valve cir-
cuit332 13223 3EC-608
PNP switch circuit 3 3 3 3 3 3 3EC-614
Start signal circuit 2EC-623
Refrigerant pressure sensor circuit 2 3 3 3 3 4EC-634
TROUBLE DIAGNOSIS
EC-419
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Air Air duct
55555 5EM-15
Air cleanerEM-15
Air leakage from air duct
(Mass air flow sensor —electric
throttle control actuator)
5555EM-15
Electric throttle control actuatorEM-17
Air leakage from intake manifold/
Collector/GasketEM-17
Cranking Battery
111111 11SC-3
Alternator circuitSC-12
Starter c irc uit 3SC-21
Signal plate 6EM-64
PNP switch
4MT-13or
AT- 3 8 8
Engine Cylinder head
55555 55 5EM-52
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-64
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nismTiming chain
55555 55 5EM-43
CamshaftEM-33
Intake valve
3EM-52
Exhaust valve
Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-22
,EX-
2Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 52EM-24
,LU-
9,LU-10,
LU-13
Oil level (Low)/Filthy oilLU-7
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
EC-430
[QR (WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
42 B/R Ignition switch[Ignition switch “OFF”]0V
[Ignition switch “ON”]BATTERY VOLTAGE
(11 - 14V)
43 G/OR PNP switch[Ignition switch “ON”]
lGear position is “P” or “N”.Approximately 0V
[Ignition switch “ON”]
lExcept the above gear positionA/T model
BATTERY VOLTAGE
(11 - 14V)
M/T model
Approximately 5V
50 LG Data link connector[Ignition switch “ON”]
lCONSULT-II or GST is disconnected.Approximately 5V
52 R/WElectrical load signal
(Rear window defog-
ger signal)[Ignition switch "ON"]
lRear window defogger switch is "ON"BATTERY VOLTAGE
(11 - 14V)
[Ignition switch "ON"]
lRear window defogger switch is "OFF"Approximately 0V
53 R/YElectrical load signal
(Headlamp signal)[Ignition switch "ON"]
lLighting switch is "2ND" positionBATTERY VOLTAGE
(11 - 14V)
[Ignition switch "ON"]
lLighting switch is "OFF"Approximately 0V
55 LG/BHeater fan switch sig-
nal[Ignition switch "ON"]
lHeater fan control switch is "ON"Approximately 0V
[Ignition switch "ON"]
lHeater fan control switch is "OFF"Approximately 5V
58 B Sensors' ground[Engine is running]
lWarm-up condition
lIdle speedApproximately 0V
59
60
106
108B
B
B/Y
B/YECM ground[Engine is running]
lIdle speedEngine ground
63 L/WCamshaft position
sensor (PHASE)[Engine is running]
lWarm-up condition
lIdle speed1.0 - 4.0V
[Engine is running]
lEngine speed is 2,000 rpm.1.0 - 4.0V
64 OR/LAccelerator pedal
position sensor 2
power supply[Ignition switch “ON”]Approximately 2.5V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB0525E
PBIB0526E