Page 483 of 1767
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
Page 485 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 0402 P9×FUEL TEMP SENZD30DDTi
EC-123
Page 486 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)
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
Page 487 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-128.
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-128.SEF817Y
DTC 0402 P9×FUEL TEMP SENZD30DDTi
EC-125
Page 491 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 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
Page 492 of 1767

Description
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.
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
ACCEL POS SENIIgnition switch: ON
(Engine stopped)Accelerator pedal: released 0.40 - 0.60V
Accelerator pedal: depressed Approx. 4.5V
FULL ACCEL SWIIgnition switch: ON
(Engine stopped)Accelerator pedal: fully depressed ON
Except above OFF
OFF ACCEL SWIIgnition switch: ON
(Engine stopped)Accelerator pedal: fully released ON
Accelerator pedal: slightly open OFF
SEF861SA
DTC 0403 ACCEL POS SENSORZD30DDTi
EC-130
Page 493 of 1767

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)
23 GAccelerator position sen-
sorIgnition switch ªONº
Accelerator pedal fully released0.4 - 0.6V
Ignition switch ªONº
Accelerator pedal fully depressedApproximately 4.5V
31 L/YAccelerator position switch
(Idle)Ignition switch ªONº
Accelerator pedal fully releasedBATTERY VOLTAGE
(11 - 14V)
Ignition switch ªONº
Accelerator pedal depressedApproximately 0V
32 R/LAccelerator position switch
(Full)Ignition switch ªONº
Accelerator pedal releasedApproximately 0V
Ignition switch ªONº
Accelerator pedal fully depressedBATTERY VOLTAGE
(11 - 14V)
48 R/BAccelerator position sen-
sor power supplyIgnition switch ªONº
Approximately 5V
51B/W
(LHD
mod-
els)
R/W
(RHD
mod-
els)Accelerator position sen-
sor groundEngine is running.
Warm-up condition
Idle speedApproximately 0V
On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
IThe relation between sensor and switch signal is not in the
normal range during the specified accelerator position.IHarness or connectors
(The sensor circuit is open or shorted.)
IAccelerator position sensor
IAccelerator position switch
IAccelerator switch (F/C)
DTC 0403 ACCEL POS SENSORZD30DDTi
EC-131
Page 500 of 1767
4 CHECK ACCELERATOR POSITION SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screw.
MEC994D
3. Check harness continuity between accelerator position sensor terminal 3 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OKEGO TO 5.
NGERepair open circuit or short to ground or short to power in harness or connectors.
5 CHECK ACCELERATOR POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 23 and accelerator position sensor terminal 2. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OKEGO TO 6.
NGERepair open circuit or short to ground or short to power in harness or connectors.
DTC 0403 ACCEL POS SENSORZD30DDTi
Diagnostic Procedure (Cont'd)
EC-138