2002 NISSAN TERRANO engine control

Component Description
The mass air flow sensor (MAFS) is placed in the stream of intake
air. It measures the intake air flow rate by measuring a part of the
entire intake air flow. It consists of a hot wire that is supplied with
electric current from the ECM. The temperature of the hot wire is
controlled by the ECM a certain amount. The heat generated by the
hot wire is reduced as the intake air flows around it. The more air,
the greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot wire as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS AIR/FL SEIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: Neutral position
INo-loadIdle 1.6 - 2.0V
ECM Terminals and Reference Value
Specification data are reference values, and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may damage the
ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
35 R Mass air flow sensorEngine is running.
Warm-up condition
Idle speed1.6 - 2.0V
49 W Sensor's power supply Ignition switch ªONº
Approximately 5V
50 B Sensor's groundEngine is running.
Warm-up condition
Idle speedApproximately 0V
On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
IAn excessively high or low voltage from the sensor is sent to
ECM.IHarness or connectors
(The sensor circuit is open or shorted.)
IMass air flow sensor
SEF987W
DTC 0102 MASS AIR FLOW SENZD30DDTi
EC-88

Diagnostic Procedure
1 CHECK ECTS POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect engine coolant temperature sensor harness connector.
MEC022E
3. Turn ignition switch ªONº.
4. Check voltage between ECTS terminal 2 and ground with CONSULT-II or tester.
SEF401Y
OK or NG
OKEGO TO 3.
NGEGO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E225, F108
IHarness connectors F135, M842 (RHD models)
IHarness for open or short between engine control temperature sensor and ECM
ERepair open circuit or short to ground or short to power in harness or connectors.
3 CHECK ECTS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between ECTS terminal 1 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OKEGO TO 5.
NGEGO TO 4.
DTC 0103 COOLANT TEMP SENZD30DDTi
EC-97

Description
The accelerator switch is installed to the accelerator pedal assem-
bly. The switch senses accelerator position and sends an ON-OFF
signal to the ECM. The ECM uses the signal to control the fuel cut
operation at deceleration for better fuel efficiency.
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SW (FC)IIgnition switch: ON
(Engine stopped)Accelerator pedal: fully released CLOSE
Accelerator pedal: slightly open OPEN
DECELER F/CUTIEngine: After warming up Idle OFF
ECM Terminals and Reference Value
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may damage the
ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
29 LG/R Accelerator switch (F/C)Ignition switch ªONº
Accelerator pedal fully releasedBATTERY VOLTAGE
(11 - 14V)
Ignition switch ªONº
Accelerator pedal depressedApproximately 0V
On Board Diagnosis Logic
Malfunction is detected when .... Check Items (Possible Cause)
IThe OFF signal (short) is sent to the ECM for a certain period
of time even when the accelerator pedal is not being
depressed.IHarness or connectors
(The switch circuit is shorted.)
IAccelerator switch (F/C)
MEC986D
DTC 0203 ACCEL POS SW (F/C)ZD30DDTi
EC-104

Description
SYSTEM DESCRIPTION
Sensor Input signal to ECM ECM function Actuator
Vehicle speed sensor Vehicle speed
Cooling fan con-
trolCooling fan relay Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch Air conditioner ªONº signal
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, air condi-
tioner ON signal. The control system has 2-step control [ON/OFF].
OPERATION
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
AIR COND SIGIEngine: After warming up, idle the
engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
COOLING FANIWhen cooling fan is stopped. OFF
IWhen cooling fan operates. ON
SEF450Z
DTC 0208 OVER HEATZD30DDTi
EC-109

Description
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The unit controls the engine.
On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
IECM calculation function is malfunctioning.IECM
DTC Confirmation Procedure
WITH CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and wait at least 2 seconds.
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-122.
WITHOUT CONSULT-II
1) Turn ignition switch ªONº and wait at least 2 seconds.
2) Start engine and wait at least 2 seconds.
3) Turn ignition switch ªOFFº, wait at least 5 seconds and then turn
ªONº.
4) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º with
ECM.
5) If DTC is detected, go to ªDiagnostic Procedureº, EC-122.
SEC220B
SEF817Y
DTC 0301 ECM 2, DTC 0901 ECM 12ZD30DDTi
EC-121

Description
SYSTEM DESCRIPTION
The ECM and the electronic control fuel injection pump control unit
(abbreviated as the injection pump control unit) perform the real
time communication (signal exchange).
The ECM transmits the signals of the target fuel injection amount,
target fuel injection timing, and engine speed, etc., and receives the
signals of the pump speed and fuel temperature, etc. from the
injection pump control unit.
By those signals, the injection pump controls the optimum fuel
injection amount and injection timing of the spill valve and timing
control valve.
Injection pump control unit has an on board diagnostic system,
which detects malfunctions related to sensors or actuators built-into
electronic control fuel injection pump. These malfunction informa-
tion are transferred through the line (circuit) from injection pump
control unit to ECM.
FUEL INJECTION AMOUNT CONTROL
In accordance with the target fuel injection amount signal from the
ECM, the injection amount is controlled by controlling the spill valve
in the injection pump and by changing the needle opening time.
FUEL INJECTION TIMING CONTROL
Based on the target fuel injection timing signal from the ECM, the
injection timing is controlled in accordance with the timer spring by
performing the duty control of the timing control valve in the injec-
tion pump and by adjusting the pressure of the timer piston high
pressure chamber.
FUEL TEMPERATURE SENSOR
The sensor detects the fuel temperature in the injection pump and
calibrates the injection amount change by the fuel temperature.
CAM RING POSITION SENSOR
The sensor detects the passing of the protrusion on the sensor
wheel in the injection pump by the semiconductor magnetic resis-
tance element sensor. The cam ring position sensor synchronizes
with the cam ring, and detects the actual advance amount. The
injection pump control unit measures the injection pump revolution
by the signal of the cam ring position sensor.
SEF437Y
DTC 0402 P9×FUEL TEMP SENZD30DDTi
EC-123

CONSULT-II Reference Value in Data Monitor
Mode
Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL TEMP SENIEngine: After warming up More than 40ÉC (104ÉF)
SPILL/VIEngine: After warming up Approx. 13ÉCA
INJ TIMG C/VIEngine: After warming up,
idle the engine.Approx. 50 - 70%
DECELER F/CUTIEngine: After warm-
ing upIdle OFF
BARO SENIIgnition switch: ONAltitude
Approx.0m(0ft): Approx. 100.62 kPa (1.0062 bar, 1.026 kg/cm
2, 14.59
psi)
Approx. 1,000 m (3,281 ft): Approx. 88.95 kPa (0.8895 bar, 0.907 kg/cm
2,
12.90 psi)
Approx. 1,500 m (4,992 ft): Approx. 83.16 kPa (0.8316 bar, 0.848 kg/cm
2,
12.06 psi)
Approx. 2,000 m (6,562 ft): Approx. 78.36 kPa (0.7836 bar, 0.799 kg/cm
2,
11.36 psi)
ECM Terminals and Reference Value
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may damage the
ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
33 GElectronic control fuel
injection pumpEngine is running.
Warm-up condition
Idle speedApproximately 2.5V
40 RElectronic control fuel
injection pumpEngine is running.
Warm-up condition
Idle speedApproximately 2.5V
52 YElectronic control fuel
injection pumpEngine is running.
Idle speedApproximately 0.1V
53 ORElectronic control fuel
injection pumpEngine is running.
Idle speedApproximately 0.35V
On Board Diagnosis Logic
Malfunction is detected when .... Check Items (Possible cause)
IAn improper voltage signal from fuel temperature sensor
(Built-into electronic control fuel injection pump) is sent to
injection pump control unit.IHarness or connectors
(Electronic control fuel injection pump circuit is open or
shorted.)
IElectronic control fuel injection pump
DTC 0402 P9×FUEL TEMP SENZD30DDTi
EC-124

4 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E231, E220
IHarness for open or short between electronic control fuel injection pump and engine ground
ERepair open circuit or short to ground or short to power in harness or connectors.
5 CHECK COMMUNICATION LINE FOR OPEN AND SHORT
1. Check continuity between the following terminals. Refer to Wiring Diagram.
MTBL0444
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OKEGO TO 7.
NGEGO TO 6.
6 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E231, E220
IHarness connectors E227, F106
IHarness connectors F135, M842 (RHD models)
IHarness for open or short between electronic control fuel injection pump and ECM
ERepair open circuit or short to ground or short to power in harness or connectors.
7 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-78.
OK or NG
OKEReplace electronic control fuel injection pump.
NGERepair open circuit or short to ground or short to power in harness or connectors.
DTC 0402 P9×FUEL TEMP SENZD30DDTi
Diagnostic Procedure (Cont'd)
EC-129