Page 584 of 1767

Description
SYSTEM DESCRIPTION
Sensor Input Signal to ECM ECM Function Actuator
Electronic controlled fuel injection pump Fuel injection signal
EGR volume
controlEGR volume control valve Crankshaft position sensor (TDC) Engine speed
Vehicle speed sensor Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
Battery Battery voltage
Mass air flow sensor Amount of intake air
Air conditioner switch Air conditioner operation
Electrical load Electrical load signal
PNP switch Park/Neutral position signal
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.
IEngine stopped
IEngine starting
ILow engine coolant temperature
IExcessively high engine coolant temperature
IHigh engine speed
IWide open throttle
ILow battery voltage
COMPONENT DESCRIPTION
EGR volume control valve
The EGR volume control valve uses a step motor to control the flow
rate of EGR from exhaust manifold. This motor has four winding
phases. It operates according to the output pulse signal of the
ECM. Two windings are turned ON and OFF in sequence. Each
time an ON pulse is issued, the valve opens or closes, changing
the flow rate. When no change in the flow rate is needed, the ECM
does not issue the pulse signal. A certain voltage signal is issued
so that the valve remains at that particular opening.
SEF908Y
SEF411Y
DTC 1003 EGR VOLUME CONT/VZD30DDTi
EC-222
Page 585 of 1767

CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
EGR VOL CON/VIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: Neutral position
INo-loadAfter 1 minute at idle More than 10 steps
Revving engine up to 3,200 rpm
quickly0 step
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)
103 R/Y
(LHD
mod-
els)
L/R
(RHD
mod-
els)EGR volume control valveEngine is running.
Warm-up condition
Idle speed0.1 - 14V
105
109
11 5G/Y
Y/B
R/L
On Board Diagnosis Logic
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
1003IAn excessively low voltage signal is sent to ECM.IHarness or connectors
(The EGR volume control valve circuit is open or
shorted.)
IEGR volume control valve
DTC 1003 EGR VOLUME CONT/VZD30DDTi
EC-223
Page 586 of 1767
DTC Confirmation Procedure
WITH CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Turn ignition switch ªOFFº, and immediately turn ªONº within 1
second.
4) Start engine and let it idle.
5) If DTC is detected, go to ªDiagnostic Procedureº, EC-227.
WITHOUT CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Turn ignition switch ªOFFº, and immediately turn ªONº within 1
second.
3) Start engine and let it idle.
4) Turn ignition switch ªOFFº, wait at least 5 seconds and then turn
ªONº.
5) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º with
ECM.
6) If DTC is detected, go to ªDiagnostic Procedureº, EC-227.SEF817Y
DTC 1003 EGR VOLUME CONT/VZD30DDTi
EC-224
Page 594 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 1004 FUEL CUT SYSTEM1ZD30DDTi
EC-232
Page 595 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)
IFuel cut control system does not function properly.IHarness or connectors
(Electronic control fuel circuit is open or shorted.)
IElectronic control fuel
DTC 1004 FUEL CUT SYSTEM1ZD30DDTi
EC-233
Page 596 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) Turn ignition switch ªOFFº, wait at least 5 seconds and then turn
ªONº.
5) If DTC is detected, go to ªDiagnostic Procedureº, EC-237.
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-237.
SEF817Y
DTC 1004 FUEL CUT SYSTEM1ZD30DDTi
EC-234
Page 600 of 1767

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 1004 FUEL CUT SYSTEM1ZD30DDTi
Diagnostic Procedure (Cont'd)
EC-238
Page 601 of 1767

Description
SYSTEM DESCRIPTION
Sensor Input Signal to ECMECM
FunctionActuator
Crankshaft position
sensor (TDC)Engine speed
Glow
controlGlow lamp,
Glow relay
"
Glow plugs Engine coolant tem-
perature sensorEngine coolant tem-
perature
When engine coolant temperature is more than approximately 75ÉC
(167ÉF), the glow relay turns off, inactivating the quick-glow control
until coolant temperature drops below approximately 55ÉC (131ÉF).
When coolant temperature is lower than approximately 75ÉC
(167ÉF):
IIgnition switch ON
After ignition switch has turned to ON, the glow relay turns ON
for a certain period of time in relation to engine coolant
temperature, allowing current to flow through glow plug.
ICranking
The glow relay turns ON, allowing current to flow through glow
plug.
IStarting
After engine has started, current continues to flow through glow
plug (after-glow mode) for a certain period in relation to engine
coolant temperature.
When engine speed exceeds approximately 4,800 rpm, current
flow through glow plug is interrupted.
The glow indicator lamp turns ON for a certain period of time in
relation to engine coolant temperature at the time glow relay is
turned ON.
COMPONENT DESCRIPTION
Glow plug
IThe glow plug is provided with a ceramic heating element to
obtain a high-temperature resistance. It glows in response to a
signal sent from the ECM, allowing current to flow through the
glow plug via the glow relay.
IThis engine uses two types of glow plugs.
Type A has a blue or yellow paint mark.
Type B has no paint mark.
The location of the paint mark is shown in the figure.
WARNING:
Do not use two types of glow plugs at the same time.
SEF376Y
SEF280Z
GLOW CONTROL SYSTEMZD30DDTi
EC-239