ENGINE CONTROL SYSTEM NISSAN

TROUBLE DIAGNOSIS

DTC

Description

DTC 0102 MASS AIR FLOW SEN
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.
DTC 0103 COOLANT TEMP SEN
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine cool-ant
temperature input. The sensor uses a thermistor which is sen-sitive
to the change in temperature. The electrical resistance of the
thermistor decreases as temperature increases.
DTC 0104 VEHICLE SPEED SEN
The vehicle speed sensor is installed in the transaxle. It contains a
pulse generator which provides a vehicle speed signal to the
speedometer. The speedometer then sends a signal to the ECM.
DTC 0203 ACCEL POS SW (F/C)
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.
DTC 0208 OVER HEAT
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].
DTC 0301 ECM 2, DTC 0901 ECM 12
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The unit controls the engine.
DTC 0402 P9×FUEL TEMP SEN
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.
DTC 0403 ACCEL POS SENSOR
The accelerator position sensor is installed on the upper end of the accelerator pedal assembly. The sensor
detects the accelerator position and sends a signal to the ECM. The ECM uses the signal to determine the
amount of fuel to be injected.
The accelerator position switch detects Off-accelerator switch signal and Full-accelerator switch signal and
send these signals to the ECM. The ECM will then determine engine idle conditions. These signals are also
used for diagnosing the accelerator position sensor.
DTC 0406 INT AIR VOL
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DTC 0407 CRANK POS SEN (TDC)
The crankshaft position sensor (TDC) monitors engine speed by
means of signals from the sensing plate (with three protrusions)
installed to the crankshaft pulley. The data signal output is detected
at ATDC 70° and sent to the ECM. The sensor signal is used for
fuel injection control and fuel injection timing control.
DTC 0502 BATTERY VOLTAGE
The ECM checks if battery voltage is within the tolerance range for the engine control system.
DTC 0504 A/T COMM LINE
These circuit lines are used to control the smooth shifting up and down of A/T during the hard acceleration/
deceleration.
Voltage signals are exchanged between ECM and TCM (Transmission control module).
DTC 0701 P1×CAM POS SEN
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.
DTC 0702 P2×TDC PULSE SIG
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.
DTC 0703 P3×PUMP COMM LINE
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.
DTC 0704 P4×SPILL/V CIRC, DTC 0706 P6×SPILL VALVE
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.
DTC 0705 P5×PUMP C/MODULE
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.
DTC 0707 P7×F/INJ TIMG FB
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.
DTC 0802 ECM 10
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The unit controls the engine.
DTC 0804 ECM 11
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The unit controls the engine.
DTC 0807 ECM 14
The stop lamp switch is installed to brake pedal bracket. The switch
senses brake pedal position and sends an ON-OFF signal to the
ECM. The ECM uses the signal to control the fuel injection control
system.
DTC 0902 ECM RLY
Specification data are reference values and are measured between each terminal and ground.
DTC 0903 ECM 15
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The unit controls the engine.
DTC 0905 TURBO PRESSURE
The charge air pressure sensor detects pressure in the exit side of
the charge air cooler. The sensor output voltage to the ECM
increases as pressure increases. The charge air pressure sensor
is not used to control the engine system under normal conditions.
DTC 1003 EGR VOLUME CONT/V
This system controls flow rate of EGR led from exhaust manifold
to intake manifold. The opening of the EGR by-pass passage in the
EGR volume control valve changes to control the flow rate. A
built-in step motor moves the valve in steps corresponding to the
ECM output pulses. The opening of the valve varies for optimum
engine control. The optimum value stored in the ECM is determined
by considering various engine conditions.
The EGR volume control valve remains close under the following
conditions.
DTC 1004 FUEL CUT SYSTEM1
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.