
Basic InspectionNJEC0632Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
+Headlamp switch is OFF,
+On vehicles equipped with daytime light systems, set
lighting switch to the 1st position to light only small
lamps.
+Air conditioner switch is OFF,
+Rear defogger switch is OFF,
+Steering wheel is in the straight-ahead position, etc.
1 INSPECTION START
1. Check service records for any recent repairs that may indicate a related problem.
2. Check the current need for scheduled maintenance, especially for fuel filter and air cleaner filter. Refer to MA-4, ªPeri-
odic Maintenanceº.
3. Open engine hood and check the following:
+Harness connectors for improper connections
+Vacuum hoses for splits, kinks, or improper connections
+Wiring for improper connections, pinches, or cuts
SEF142I
4. Start engine and warm it up to the normal operating temperature.
©GO TO 2.
2 PREPARATION FOR CHECKING IDLE SPEED
With CONSULT-II
Connect CONSULT-II to the data link connector.
Without CONSULT-II
Install diesel tacho tester to the vehicle.
©GO TO 3.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONYD
Basic Inspection
EC-536

CONSULT-II Reference Value in Data Monitor
Mode
NJEC0634Remarks:
+Specification data are reference values.
+Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
MONITOR ITEM CONDITION SPECIFICATION
CKPS´RPM (TDC)
+Tachometer: Connect
+Run engine and compare tachometer indication with the CONSULT-II
value.Almost the same speed as the
CONSULT-II value. CMPS´RPM-
PUMP
COOLAN TEMP/S+Engine: After warming up More than 70ÉC (158ÉF)
VHCL SPEED SE+Turn drive wheels and compare speedometer indication with the
CONSULT-II valueAlmost the same speed as the
CONSULT-II value
FUEL TEMP SEN+Engine: After warming up More than 40ÉC (104ÉF)
ACCEL POS SEN+Ignition switch: ON
(Engine stopped)Accelerator pedal: fully released 0.30 - 0.50V
Accelerator pedal: fully depressed 3.0 - 4.3V
OFF ACCEL SW+Ignition switch: ON
(Engine stopped)Accelerator pedal: fully released ON
Accelerator pedal: slightly open OFF
SPILL/V+Engine: After warming up, idle the engine. Approx. 12 - 13ÉCA
BATTERY VOLT+Ignition switch: ON (Engine stopped) 11 - 14V
P/N POSI SW*1
(where fitted)+Ignition switch: ONShift lever: Neutral position ON
Except above OFF
START SIGNAL+Ignition switch: ON®START®ON OFF®ON®OFF
IGN SW+Ignition switch: ON®OFF ON®OFF
BRAKE SW+Ignition switch: ONBrake pedal: depressed ON
Brake pedal: released OFF
BRAKE SW2+Ignition switch: ONBrake pedal: depressed ON
Brake pedal: released OFF
MAS AIR/FL SE+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: Neutral position
+No-loadIdle 1.5 - 2.0V
INT/A VOLUME+Engine: After warming up, idle the engine. 150 - 450 mg/st
F/CUT SIGNAL+Engine: After warming up Idle ON
GLOW RLY+Refer to EC-677.
COOLING FAN+When cooling fan is stopped. OFF
+When cooling fans operate at low speed. LOW
+When cooling fans operate at high speed. HIGH
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONYD
CONSULT-II Reference Value in Data Monitor Mode
EC-551

exceed 10 km/h (6 MPH) when rotating wheels with suit-
able gear position.
4) If NG, go to ªDiagnostic Procedureº, EC-596.
WITHOUT CONSULT-IINJEC0657S021) Lift up the vehicle.
2) Start engine.
3) Read the voltage signal for the vehicle speed sensor with an
oscilloscope. Refer to ªECM Terminals and Reference Valueº,
EC-593.
4) Verify that the oscilloscope screen shows the signal wave as
shown at ªECM Terminals and Reference Valueº, EC-593.
5) If NG, go to ªDiagnostic Procedureº, EC-596.
DTC P0500 VEHICLE SPEED SENYD
Overall Function Check (Cont'd)
EC-594

SEF437Y
DescriptionNJEC0672SYSTEM DESCRIPTIONNJEC0672S01The 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 CONTROLNJEC0672S02In 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 CONTROLNJEC0672S03Based 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 SENSORNJEC0672S04The sensor detects the fuel temperature in the injection pump and
calibrates the injection amount change by the fuel temperature.
CAMSHAFT POSITION SENSORNJEC0672S05The sensor detects the passing of the protrusion on the sensor
wheel in the injection pump by the semiconductor magnetic resis-
tance element sensor. The camshaft 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 camshaft position sensor.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0673Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL TEMP SEN+Engine: After warming up More than 40ÉC (104ÉF)
SPILL/V+Engine: After warming up, idle the engine. Approx. 12 - 13ÉCA
INT/A VOLUME+Engine: After warming up, idle the engine. Approx. 150 - 450 mg/st
F/CUT SIGNAL+Engine: After warming up Idle ON
DTC P1180 P9´FUEL TEMP SENYD
Description
EC-606

SEF437Y
DescriptionNJEC0753SYSTEM DESCRIPTIONNJEC0753S01The 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 CONTROLNJEC0753S02In 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 CONTROLNJEC0753S03Based 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 SENSORNJEC0753S04The sensor detects the fuel temperature in the injection pump and
calibrates the injection amount change by the fuel temperature.
CAM RING POSITION SENSORNJEC0753S05The 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.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0754Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL TEMP SEN+Engine: After warming up More than 40ÉC (104ÉF)
SPILL/V+Engine: After warming up, idle the engine. Approx. 12 - 13ÉCA
INT/A VOLUME+Engine: After warming up, idle the engine. Approx. 150 - 450 mg/st
F/CUT SIGNAL+Engine: After warming up Idle ON
DTC P1202 FUEL CUT SYSTEM2YD
Description
EC-612

SEF437Y
DescriptionNJEC0727SYSTEM DESCRIPTIONNJEC0727S01The 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 CONTROLNJEC0727S02In 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 CONTROLNJEC0727S03Based 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 SENSORNJEC0727S04The sensor detects the fuel temperature in the injection pump and
calibrates the injection amount change by the fuel temperature.
CAM RING POSITION SENSORNJEC0727S05The 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.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0728Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL TEMP SEN+Engine: After warming up More than 40ÉC (104ÉF)
SPILL/V+Engine: After warming up, idle the engine. Approx. 12 - 13ÉCA
INT/A VOLUME+Engine: After warming up, idle the engine. Approx. 150 - 450 mg/st
F/CUT SIGNAL+Engine: After warming up Idle ON
DTC P1241 P7´F/INJ TIMG FBYD
Description
EC-634

SEF437Y
DescriptionNJEC0714SYSTEM DESCRIPTIONNJEC0714S01The 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 CONTROLNJEC0714S02In 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 CONTROLNJEC0714S03Based 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 SENSORNJEC0714S04The sensor detects the fuel temperature in the injection pump and
calibrates the injection amount change by the fuel temperature.
CAM RING POSITION SENSORNJEC0714S05The 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.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0715Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL TEMP SEN+Engine: After warming up More than 40ÉC (104ÉF)
SPILL/V+Engine: After warming up, idle the engine. Approx. 12 - 13ÉCA
INT/A VOLUME+Engine: After warming up, idle the engine. Approx. 150 - 450 mg/st
F/CUT SIGNAL+Engine: After warming up Idle ON
DTC P1251 P4´SPILL/V CIRCYD
Description
EC-640

SEF437Y
DescriptionNJEC0700SYSTEM DESCRIPTIONNJEC0700S01The 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 CONTROLNJEC0700S02In 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 CONTROLNJEC0700S03Based 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 SENSORNJEC0700S04The sensor detects the fuel temperature in the injection pump and
calibrates the injection amount change by the fuel temperature.
CAM RING POSITION SENSORNJEC0700S05The 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.
CONSULT-II Reference Value in Data Monitor
Mode
NJEC0701Remarks: Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL TEMP SEN+Engine: After warming up More than 40ÉC (104ÉF)
SPILL/V+Engine: After warming up, idle the engine. Approx. 12 - 13ÉCA
INT/A VOLUME+Engine: After warming up, idle the engine. Approx. 150 - 450 mg/st
F/CUT SIGNAL+Engine: After warming up Idle ON
DTC P1337 P2´DTC PULSE SIGYD
Description
EC-646