Page 537 of 1767

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 0703 P3×PUMP COMM LINEZD30DDTi
EC-175
Page 538 of 1767

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)
IInjection pump control unit receives incorrect voltage signal
from ECM continuously.IHarness or connectors
(Electronic control fuel injection pump circuit is open or
shorted.)
IElectronic control fuel injection pump
DTC 0703 P3×PUMP COMM LINEZD30DDTi
EC-176
Page 539 of 1767
DTC Confirmation Procedure
WITH CONSULT-II
1) Turn ignition switch ªONº and wait at least 2 seconds.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and run it for at least 2 seconds at idle speed.
(If engine does not run, turn ignition switch to ªSTARTº for at
least 2 seconds.)
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-180.
WITHOUT CONSULT-II
1) Turn ignition switch ªONº and wait at least 2 seconds.
2) Start engine and run it for at least 2 seconds at idle speed.
(If engine does not run, turn ignition switch to ªSTARTº for 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-180.SEF817Y
DTC 0703 P3×PUMP COMM LINEZD30DDTi
EC-177
Page 540 of 1767
Wiring Diagram
LHD MODELS
YEC181A
DTC 0703 P3×PUMP COMM LINEZD30DDTi
EC-178
Page 541 of 1767
RHD MODELS
YEC182A
DTC 0703 P3×PUMP COMM LINEZD30DDTi
Wiring Diagram (Cont'd)
EC-179
Page 542 of 1767

Diagnostic Procedure
1 CHECK ELECTRONIC CONTROL FUEL INJECTION PUMP POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect electronic control fuel injection pump harness connector.
MEC025E
3. Turn ignition switch ªONº.
4. Check voltage between electronic control fuel injection pump terminal 7 and ground.
MEC977DVoltage: Battery voltage
OK or NG
OKEGO TO 3.
NGEGO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M787, F66 (LHD models)
IHarness connectors F108, E225
IHarness connectors E220, E231
IHarness connectors M842, F135 (RHD models)
IHarness for open or short between electronic control fuel injection pump and ECM
IHarness for open or short between electronic control fuel injection pump and ECM relay
ERepair open circuit or short to ground or short to power in harness or connectors.
3 CHECK ELECTRONIC CONTROL FUEL INJECTION PUMP GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between electronic control fuel injection pump terminal 6 and 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 0703 P3×PUMP COMM LINEZD30DDTi
EC-180
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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 E227, F106
IHarness connectors E231, E220
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 0703 P3×PUMP COMM LINEZD30DDTi
Diagnostic Procedure (Cont'd)
EC-181
Page 544 of 1767

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 0704 P4×SPILL/V CIRC, DTC 0706 P6×SPILL VALVEZD30DDTi
EC-182