Page 338 of 1833

SYSTEM Ð ENGINE CONTROL system
Malfunction
SYMPTOM
Reference page
Feature of symptom, Check pointROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEAT/HIGH ENGINE COOLANT TEMPERATURE
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
ABNORMAL SMOKE COLOR
DEAD BATTERY (UNDER CHARGE)
Malfunction indicator lamp illuminates.
Can be detected by CONSULT-II?
Fuel cut BLACK SMOKE
WHITE SMOKEWarranty symptom code
AG AH AJ AK AL AM AP HA
ENGINE CONTROL
Start signal circuit*a, *b EC-253 *3
PNP switch circuit *a, *b
1 1 EC-256
*c
Accelerator position switch (Idle) cir-
cuit *a, *c
EC-130
*b 1 1 *4
Accelerator position switch (Full) cir-
cuit *a, *b 1 1 EC-130
Ignition switch circuit *a
EC-79
*b *5
Power supply for ECM circuit *a
111
EC-79
*b
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*3: Start control does not function.
*4: Accelerator position sensor NG signal is output.
*5: Engine does not stop.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
Symptom Matrix Chart (Cont'd)
EC-63
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Page 339 of 1833

SYSTEM Ð ENGINE CONTROL system
Malfunction
SYMPTOM
Reference page
Feature of symptom, Check pointHARD/NO
START/RESTART
(EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
KNOCK/DETONATION
LACK OF POWER
POOR ACCELERATION
HI IDLE
LOW IDLE NO START (with first firing)
NO START (without first firing)
HARD TO START WHEN ENGINE IS COLD
HARD TO START WHEN ENGINE IS HOT
AT IDLE
DURING DRIVING
WHEN DECELERATINGWarranty symptom code AAAB AC AD AE AF
ENGINE CONTROL
EGR volume control valve circuit *a, *b
EC-227
*c *8
Glow relay circuit *a 1111
EC-244*9
*b *10
ECM relay (Self-shutoff) circuit *a 111
EC-79
*b *11
ECM, Connector circuit *a, *b 2222222222222 EC-121,
205, 218
Air conditioner relay circuit *a
EC-308*12
*b *13
Air conditioner switch circuit *a, *c
EC-308*13
*b *14
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*8: Does not stop operating.
*9: Glow lamp does not turn on.
*10: Glow lamp does not turn off. *11: Ground short makes engine unable to stop.
*12: Air conditioner does not operate.
*13: Air conditioner does not stop operating.
*14: Air conditioner does not work.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
Symptom Matrix Chart (Cont'd)
EC-64
http://vnx.su/
Page 340 of 1833

SYSTEM Ð ENGINE CONTROL system
Malfunction
SYMPTOM
Reference page
Feature of symptom, Check pointROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEAT/HIGH ENGINE COOLANT TEMPERATURE
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
ABNORMAL SMOKE COLOR
DEAD BATTERY (UNDER CHARGE)
Malfunction indicator lamp illuminates.
Can be detected by CONSULT-II?
Fuel cut BLACK SMOKE
WHITE SMOKEWarranty symptom code
AG AH AJ AK AL AM AP HA
ENGINE CONTROL
EGR volume control valve circuit*a, *b
EC-227
*c 1 *8
Glow relay circuit *a 1
EC-244*9
*b *10
ECM relay (Self-shutoff) circuit *a 1
EC-79
*b 1 1 *11
ECM, Connector circuit *a, *b 222222222222 EC-121,
205, 218
Air conditioner relay circuit *a
EC-308*12
*b *13
Air conditioner switch circuit *a, *c
EC-308*13
*b *14
1 - 5: The numbers refer to the order of inspection.
*a: Open
*b: Short
*c: Ground short
*d: Noise
*8: Does not stop operating.
*9: Glow lamp does not turn on.
*10: Glow lamp does not turn off.
*11: Ground short makes engine unable to stop.
*12: Air conditioner does not operate.
*13: Air conditioner does not stop operating.
*14: Air conditioner does not work.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
Symptom Matrix Chart (Cont'd)
EC-65
http://vnx.su/
Page 357 of 1833
DIAGNOSTIC PROCEDURE
1 INSPECTION START
Start engine.
Is engine running?YesorNo
Ye s EGO TO 14.
No EGO TO 2.
2 CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ªONº.
2. Check voltage between ECM terminal 38 and ground with CONSULT-II or tester.
SEF397Y
OK or NG
OK EGO TO 4.
NG EGO TO 3.
3 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.
4 CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminals 39, 43, 106, 112, 118 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
OK EGO TO 6.
NG EGO TO 5.
TROUBLE DIAGNOSIS FOR POWER SUPPLYZD30DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-82
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Page 358 of 1833
5 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.
6 CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector.
2. Turn ignition switch ªONº and then ªOFFº.
3. Check voltage between ECM terminals 56, 61, 116 and ground with CONSULT-II or tester.
SEF288Z
OK or NG
OK ECheck electronic control fuel injection pump power supply circuit. Refer to ªDiagnostic
Procedureº, EC-185.
NG (Battery voltage does not
exist.) EGO TO 7.
NG (Battery voltage exists for
more than a few seconds.) EGO TO 13.
TROUBLE DIAGNOSIS FOR POWER SUPPLYZD30DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-83
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 363 of 1833

Component Description
The mass air flow sensor (MAFS) is placed in the stream of intake
air. It measures the intake air flow rate by measuring a part of the
entire intake air flow. It consists of a hot wire that is supplied with
electric current from the ECM. The temperature of the hot wire is
controlled by the ECM a certain amount. The heat generated by the
hot wire is reduced as the intake air flows around it. The more air,
the greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot wire as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEMCONDITION SPECIFICATION
MAS AIR/FL SE I
Engine: After warming up
I Air conditioner switch: ªOFFº
I Shift lever: Neutral position
I No-load Idle
1.6 - 2.0V
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)
35 R Mass air flow sensor Engine is running.
Warm-up condition
Idle speed 1.6 - 2.0V
49 W Sensor's power supply Ignition switch ªONº
Approximately 5V
50 B Sensor's ground Engine is running.
Warm-up condition
Idle speed Approximately 0V
On Board Diagnosis Logic
Malfunction is detected when ...
Check Items (Possible Cause)
I An excessively high or low voltage from the sensor is sent to
ECM. I
Harness or connectors
(The sensor circuit is open or shorted.)
I Mass air flow sensor
SEF987W
DTC 0102 MASS AIR FLOW SENZD30DDTi
EC-88
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Page 368 of 1833

3 CHECK MAFS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
MEC994D
3. Check harness continuity between mass air flow 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
OK EGO TO 5.
NG EGO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F135, M842 (RHD models)
I Harness for open or short between mass air flow sensor and ECM
ERepair open circuit or short to ground or short to power in harness or connectors.
5 CHECK MAFS INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between mass air flow sensor terminal 5 and ECM terminal 35. 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 7.
NG EGO TO 6.
6 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F135, M842 (RHD models)
I Harness for open or short between mass air flow sensor and ECM
ERepair open circuit or short to ground or short to power in harness or connectors.
DTC 0102 MASS AIR FLOW SENZD30DDTi
Diagnostic Procedure (Cont'd)
EC-93
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