Page 481 of 1767
16 CHECK THERMOSTAT
1. Remove thermostat.
2. Check valve seating condition at normal room temperatures.
It should seat tightly.
3. Check valve opening temperature and valve lift.
SLC343
Valve opening temperature:
82ÉC (180ÉF) [standard] (Models for cold areas)
76.5ÉC (170ÉF) [standard] (Models for except cold areas)
Valve lift:
More than 10 mm/95ÉC (0.394 in/203ÉF)
4. Check if valve is closed at 5ÉC (9ÉF) below valve opening temperature. For details, refer to LC section, ªThermostatº.
OK or NG
OKEGO TO 17.
NGEReplace thermostat.
17 CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Remove engine coolant temperature sensor.
2. Check resistance between engine coolant temperature sensor terminals 1 and 2 as shown in the figure.
SEF304X
OK or NG
OKEGO TO 18.
NGEReplace engine coolant temperature sensor.
DTC 0208 OVER HEATZD30DDTi
Diagnostic Procedure (Cont'd)
EC-119
Page 482 of 1767

18 CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to ªMAIN 12 CAUSES OF OVERHEATINGº, EC-120.
EINSPECTION END
Main 12 Causes of Overheating
Engine Step Inspection item Equipment Standard Reference page
OFF 1IBlocked radiator
IBlocked condenser
IBlocked radiator grille
IBlocked bumperIVisual No blocking Ð
2ICoolant mixtureICoolant tester 30 - 50% coolant mixture See ªRECOMMENDED
FLUIDS AND LUBRI-
CANTSº in MA section.
3ICoolant levelIVisual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee ªChanging Engine
Coolantº, ªENGINE MAIN-
TENANCEº in MA section.
4IRadiator capIPressure tester 78 - 98 kPa
(0.78 - 0.98 bar, 0.8 - 1.0
kg/cm
2, 11 - 14 psi)
59 - 98 kPa (0.59 - 0.98
bar, 0.6 - 1.0 kg/cm
2,
9 - 14 psi) (Limit)See ªSystem Checkº,
ªENGINE COOLING SYS-
TEMº in LC section.
ON*2 5ICoolant leaksIVisual No leaks See ªSystem Checkº,
ªENGINE COOLING SYS-
TEMº in LC section.
ON*2 6IThermostatITouch the upper and
lower radiator hosesBoth hoses should be hot. See ªThermostatº and
ªRadiatorº, ªENGINE
COOLING SYSTEMº in
LC section.
ON*1 7ICooling fanIVisual Operating See ªDTC 0208 OVER
HEATº, EC-109.
OFF 8ICombustion gas leakIColor checker chemical
tester 4 gas analyzerNegative Ð
ON*3 9ICoolant temperature
gaugeIVisual Gauge less than 3/4
when drivingÐ
ICoolant overflow to res-
ervoir tankIVisual No overflow during driving
and idlingSee ªChanging Engine
Coolantº, ªENGINE MAIN-
TENANCEº in MA section.
OFF*4 10ICoolant return from res-
ervoir tank to radiatorIVisual Should be initial level in
reservoir tankSee ªENGINE MAINTE-
NANCEº in MA section.
OFF 11ICylinder headIStraight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See ªInspectionº, ªCYLIN-
DER HEADº in EM sec-
tion.
12ICylinder block and pis-
tonsIVisual No scuffing on cylinder
walls or pistonSee ªInspectionº, ªCYLIN-
DER BLOCKº in EM sec-
tion.
*1: Engine running at idle.
*2: Engine running at 3,000 rpm for 10 minutes.
*3: Drive at 90 km/h (55 MPH) for 30 minutes and then let idle for 10 minutes.
*4: After 60 minutes of cool down time.
For more information, refer to ªOVERHEATING CAUSE ANALYSISº in LC section.
DTC 0208 OVER HEATZD30DDTi
Diagnostic Procedure (Cont'd)
EC-120
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 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 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 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
Page 502 of 1767
9 RESET ACCELERATOR POSITION SENSOR IDLE POSITION MEMORY
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Let engine idle for 10 minutes.
EGO TO 10.
10 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-78.
EINSPECTION END
11 CHECK ACCELERATOR POSITION SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect accelerator position switch harness connector.
MEC995D
3. Turn ignition switch ªONº.
4. Check voltage between accelerator position switch terminal 5 and ground with CONSULT-II or tester.
SEF346X
OK or NG
OKEGO TO 13.
NGEGO TO 12.
12 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M787, F6 (LHD models)
IHarness for open or short between accelerator position switch and ECM relay
IHarness for open or short between accelerator position switch and ECM
ERepair harness or connectors.
DTC 0403 ACCEL POS SENSORZD30DDTi
Diagnostic Procedure (Cont'd)
EC-140