Page 326 of 1833
3 CHECK IDLE SPEED
With CONSULT-II
1. Select ªCKPS×RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
2. Read idle speed.
SEF817Y750 25 rpm
Without CONSULT-II
Check idle speed. 750 25 rpm
OK or NG
OK EINSPECTION END
NG EGO TO 4.
4 CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK EGO TO 5.
NG ERepair or replace.
5 BLEED AIR FROM FUEL SYSTEM
1. Stop engine.
2. Using priming pump, bleed air from fuel system. Refer to ªAir Bleedingº, EC-32.
EGO TO 6.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONZD30DDTi
Basic Inspection (Cont'd)
EC-51
http://vnx.su/
Page 333 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
Electronic control fuel injection pump
circuit *a, *b 1 1
111111111
Ð
*c, *d
Mass air flow sensor circuit *a, *c
111
EC-88
*b
Engine coolant temperature sensor
circuit *a, *b 1 1 1 1 EC-95 *1
Vehicle speed sensor circuit *a, *b 1 EC-99
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*1: Compensation according to engine coolant temperature does not function.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
Symptom Matrix Chart (Cont'd)
EC-58
http://vnx.su/
Page 334 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
Electronic control fuel injection pump
circuit*a, *b 1
111
Ð
*c, *d 1
Mass air flow sensor circuit *a, *c
1 EC-88
*b 1
Engine coolant temperature sensor
circuit *a, *b 1 1 1 1 EC-95 *1
Vehicle speed sensor circuit *a, *b 1 EC-99
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*1: Compensation according to engine coolant temperature does not function.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
Symptom Matrix Chart (Cont'd)
EC-59
http://vnx.su/
Page 335 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
Accelerator switch (FC) circuit *a, *b 1
EC-104
*c
Fuel cut system line *a, *c
EC-237
*b 1 1 1 1 *2
Accelerator position sensor circuit *a, *b 1 1 1 EC-130
Crankshaft position sensor (TDC)
circuit *a, *b
EC-152
*d 1 1
Charge air pressure sensor circuit *a,
*b, *c 1 1 EC-220
Swirl control valve control solenoid
valve circuit *a, *b
EC-271
*c 1111
Variable nozzle turbocharger control
solenoid valve circuit *a, *b 1 1
EC-289
*c 1 1
Intake air control valve control sole-
noid valve circuit *c 11111111
EC-281
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*2: Engine runs on after turning ignition switch OFF.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
Symptom Matrix Chart (Cont'd)
EC-60
http://vnx.su/
Page 336 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
Accelerator switch (FC) circuit*a, *b
1 1 EC-104
*c
Fuel cut system line *a, *c 1 1
EC-237
*b 1 *2
Accelerator position sensor circuit *a, *b 1 1 EC-130
Crankshaft position sensor (TDC) cir-
cuit *a, *b 1 1
1 1 EC-152
*d
Charge air pressure sensor circuit *a, *b, *c 1 1 EC-220
Swirl control valve control solenoid
valve circuit *a, *b 1
EC-271
*c 1 1 1
Variable nozzle turbocharger control
solenoid valve circuit *a, *b 1 1
EC-289
*c 1 1
Intake air control valve control sole-
noid valve circuit *c EC-281
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*a: Open
*b: Short
*c: Ground short
*d: Noise
*2: Engine runs on after turning ignition switch OFF.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
Symptom Matrix Chart (Cont'd)
EC-61
http://vnx.su/
Page 337 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
Start signal circuit *a, *b1 1 EC-253 *3
PNP switch circuit *a, *b
1
EC-256
*c
Accelerator position switch (Idle) cir-
cuit *a, *c
1 1 1
EC-130
*b 1 1 1*4
Accelerator position switch (Full) cir-
cuit *a, *b
1 1 1EC-130
Ignition switch circuit *a 1 111
EC-79
*b *5
Power supply for ECM circuit *a
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-62
http://vnx.su/
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
http://vnx.su/
Page 343 of 1833
Major Sensor Reference Graph in Data Monitor
Mode
The following are the major sensor reference graphs in ªDATA MONITORº mode.
ACCEL POS SEN, ªCKPS×RPM (TDC)º, ªMAS AIR/FL SEº
Below is the data for ªACCEL POS SENº, ªCKPS×RPM (TDC)º and ªMAS AIR/FL SEº when revving engine
quickly up to 3,000 rpm under no load after warming up engine to the normal operating temperature.
Each value is for reference, the exact value may vary.
SEF321Y
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
EC-68
http://vnx.su/