Page 361 of 1833
14 CHECK ECM POWER SUPPLY CIRCUIT-V
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ªONº.
3. Check voltage between ECM terminal 102 and ground with CONSULT-II or tester.
SEF290Z
OK or NG
OK EGO TO 16.
NG EGO TO 15.
15 DETECT MALFUNCTIONING PART
Check the following.
I10A fuse
I Harness for open or short between ECM and fuse
ERepair open circuit or short to ground or short to power in harness or connectors.
16 CHECK ECM POWER SUPPLY CIRCUIT-VI
1. Turn ignition switch ªOFFº.
2. Disconnect ECM relay.
MEC021E
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminals 56, 61, 116 and ECM relay terminal 5. Refer to Wiring Diagram.
Continuity should exist.
5. Also check harness for short to ground and short to power.
OK or NG
OK EGO TO 18.
NG EGO TO 17.
TROUBLE DIAGNOSIS FOR POWER SUPPLYZD30DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-86
http://vnx.su/
Page 362 of 1833

17 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M787, F66 (LHD models)
I Harness for open or short between ECM and ECM relay
ERepair open circuit or short to ground or short to power in harness or connectors.
18 CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminals 39, 43, 106, 112, 118 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OK EGO TO 20.
NG EGO TO 19.
19 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F108, E225
I Harness connectors M842, F135 (RHD models)
I Harness for open or short between ECM and engine ground
ERepair open circuit or short to ground or short to power in harness or connectors.
20 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-78.
EINSPECTION END
TROUBLE DIAGNOSIS FOR POWER SUPPLYZD30DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-87
http://vnx.su/
Page 367 of 1833
Diagnostic Procedure
1 CHECK MAFS POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect mass air flow sensor harness connector.
MEC993D
3. Turn ignition switch ªONº.
4. Check voltage between mass air flow sensor terminals 2, 4 and ground with CONSULT-II or tester.
MEC973D
MTBL1318
OK or NG
OK EGO TO 3.
NG EGO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M787, F66 (LHD models)
I Harness connectors F135, M842 (RHD models)
I Harness for open or short between mass air flow sensor and ECM
I Harness for open or short between mass air flow sensor and ECM relay
ERepair open circuit or short to ground or short to power in harness or connector.
DTC 0102 MASS AIR FLOW SENZD30DDTi
EC-92
http://vnx.su/
Page 384 of 1833
Description
SYSTEM DESCRIPTION
SensorInput signal to ECMECM functionActuator
Vehicle speed sensor Vehicle speed
Cooling fan con-
trolCooling fan relay
Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch Air conditioner ªONº signal
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, air condi-
tioner ON signal. The control system has 2-step control [ON/OFF].
OPERATION
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
AIR COND SIG I
Engine: After warming up, idle the
engine Air conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)
ON
COOLING FAN I
When cooling fan is stopped. OFF
I When cooling fan operates. ON
SEF450Z
DTC 0208 OVER HEATZD30DDTi
EC-109
http://vnx.su/
Page 385 of 1833

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
COLOR ITEM CONDITION DATA (DC Voltage)
14 LG/R Cooling fan relay Engine is running.
Cooling fan is not operating
BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Cooling fan is operating Approximately 0.1V
On Board Diagnosis Logic
This diagnosis continuously monitors the engine coolant temperature.
If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
Malfunction is detected when ...
Check Items (Possible Cause)
I Cooling fan does not operate properly (Overheat).
I Cooling fan system does not operate properly (Overheat).
I Engine coolant was not added to the system using the proper
filling method.
I Engine coolant is not within the specified range. I
Harness or connectors
(The cooling fan circuit is open or shorted.)
I Cooling fan
I Radiator hose
I Radiator
I Radiator cap
I Water pump
I Thermostat
I Fan belt
I Engine coolant temperature sensor
For more information, refer to ªMAIN 12 CAUSES OF
OVERHEATINGº, EC-120.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in the MA
section (ªChanging Engine Coolantº, ªENGINE MAINTENANCEº). Also, replace the engine oil.
1) Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Be sure to use coolant with the proper mixture ratio. Refer to MA section (ªAnti-freeze Coolant Mixture Ratioº,
ªRECOMMENDED LUBRICANTS AND FLUIDSº).
2) After refilling coolant, run engine to ensure that no water-flow noise is emitted.
DTC 0208 OVER HEATZD30DDTi
EC-110
http://vnx.su/
Page 390 of 1833
4 CHECK COOLING FAN POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect cooling fan relay.
MEC021E
3. Turn ignition switch ªONº.
4. Turn air conditioner switch ªONº.
5. Turn blower fan switch ªONº.
6. Check voltage between cooling fan relay terminals 2, 3 and ground with CONSULT-II or tester.
MEC974DVoltage: Battery voltageOK or NG
OK EGO TO 6.
NG EGO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
I10A fuse
I Harness connector F120, M812 (LHD models)
I A/C relay
I 30A fusible link
I Harness for open or short between cooling fan relay and fuse
I Harness for open or short between cooling fan relay and battery
ERepair open circuit or short to ground or short to power in harness or connectors.
DTC 0208 OVER HEATZD30DDTi
Diagnostic Procedure (Cont'd)
EC-115
http://vnx.su/
Page 391 of 1833

6 CHECK COOLING FAN GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect cooling fan motor harness connector.
MEC024E
3. Check harness continuity as follows. Refer to Wiring Diagram.
MTBL13224. Also check harness for short to ground and short to power.OK or NG
OK EGO TO 8.
NG EGO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M785, F67 (M/T models)
I Harness for open or short between cooling fan relay and cooling fan motor
I Harness for open or short between cooling fan relay and condenser
I Harness for open or short between cooling fan motor and ground
I Harness for open or short between condenser and ground
ERepair open circuit or short to ground or short to power in harness or connectors.
8 CHECK COOLING FAN OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 14 and cooling fan relay terminal 1. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK EGO TO 10.
NG EGO TO 9.
9 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M787, F66
I Harness for open or short between cooling fan relay and ECM
ERepair open circuit or short to ground or short to power in harness or connectors.
DTC 0208 OVER HEATZD30DDTi
Diagnostic Procedure (Cont'd)
EC-116
http://vnx.su/
Page 392 of 1833
10 CHECK COOLING FAN RELAY
Check continuity between cooling fan relay terminals 3 and 5 under the following conditions.
MEC975D
MTBL1319
OK or NG
OK EGO TO 11.
NG EReplace cooling fan relay.
11 CHECK COOLING FAN MOTOR
Supply battery voltage between cooling fan motor terminals 1 and 2.
MEC976DDoes the cooling fan motor operate normally?
OK or NG
OK EGO TO 12.
NG EReplace cooling fan motor.
12 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-78.
EINSPECTION END
DTC 0208 OVER HEATZD30DDTi
Diagnostic Procedure (Cont'd)
EC-117
http://vnx.su/