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 327 of 1833
6 CHECK IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and let it idle.
2. Select ªCKPS×RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
3. Read idle speed.
SEF817Y750 25 rpm
Without CONSULT-II
1. Start engine and let it idle.
2. Check idle speed. 750 25 rpm
OK or NG
OK EINSPECTION END
NG EGO TO 7.
7 DRAIN WATER FROM FUEL FILTER
Drain water from fuel filter. Refer to MA section (ªChecking and Replacing Fuel Filter and Draining Waterº, ªENGINE MAINTE-
NANCEº).
EGO TO 8.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONZD30DDTi
Basic Inspection (Cont'd)
EC-52
http://vnx.su/
Page 328 of 1833
8 CHECK IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and let it idle.
2. Select ªCKPS×RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
3. Read idle speed.
SEF817Y750 25 rpm
Without CONSULT-II
1. Start engine and let it idle.
2. Check idle speed. 750 25 rpm
OK or NG
OK EINSPECTION END
NG EGO TO 9.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONZD30DDTi
Basic Inspection (Cont'd)
EC-53
http://vnx.su/
Page 329 of 1833
9 CHECK AIR CLEANER FILTER
Check air cleaner filter for clogging or breaks.OK or NG
OK EGO TO 10.
NG EReplace air cleaner filter.
10 CHECK FUEL INJECTION NOZZLE
Check fuel injection nozzle opening pressure. Refer to ªInjection pressure testº, EC-26.
OK or NG
OK EGO TO 11.
NG EReplace fuel injection nozzle assembly.
11 CHECK IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and let it idle.
2. Select ªCKPS×RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
3. Read idle speed.
SEF817Y750 25 rpm
Without CONSULT-II
1. Start engine and let it idle.
2. Check idle speed. 750 25 rpm
OK or NG
OK EINSPECTION END
NG EGO TO 12.
12 CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM section, ªMEASUREMENT OF COMPRESSION PRESSUREº.
OK or NG
OK EGO TO 13.
NG EFollow the instruction of ªMEASUREMENT OF COMPRESSION PRESSUREº.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONZD30DDTi
Basic Inspection (Cont'd)
EC-54
http://vnx.su/
Page 330 of 1833
13 CHECK IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and let it idle.
2. Select ªCKPS×RPM (TDC)º in ªDATA MONITORº mode with CONSULT-II.
3. Read idle speed.
SEF817Y750 25 rpm
Without CONSULT-II
1. Start engine and let it idle.
2. Check idle speed. 750 25 rpm
OK or NG
OK EINSPECTION END
NG EReplace electronic control fuel injection pump.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONZD30DDTi
Basic Inspection (Cont'd)
EC-55
http://vnx.su/
Page 331 of 1833

Symptom Matrix Chart
SYSTEM Ð Basic engine control sys-
temSYMPTOM
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
Electronic control fuel injection pump
mainframe 4444444445534 Ð *1
Injection nozzle 33333333344 3 EC-24 *2
Glow system 1111 EC-244
Engine body 3333333 344 3 EM section *3
EGR system 3 3 EC-227
Air cleaner and ducts 3 3 MA section *4
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*1: Fuel injection system malfunction or fuel injection timing control system malfunction may be the cause.
*2: Depends on open-valve pressure and spray pattern.
*3: Caused mainly by insufficient compression pressure.
*4: Symptom varies depending on off-position of air duct, etc.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
EC-56
http://vnx.su/
Page 332 of 1833

SYSTEM Ð Basic engine control sys-
temSYMPTOM
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
Electronic control fuel injection pump
mainframe 443 4 54 333 Ð *1
Injection nozzle 3 34 EC-24 *2
Glow system 1 EC-244
Engine body 3 3 3 3 3 3 EM section *3
EGR system 3 EC-227
Air cleaner and ducts 3 3 MA section *4
1 - 5: The numbers refer to the order of inspection.
(continued on next page)
*1: Fuel injection system malfunction or fuel injection timing control system malfunction may be the cause.
*2: Depends on open-valve pressure and spray pattern.
*3: Caused mainly by insufficient compression pressure.
*4: Symptom varies depending on off-position of air duct, etc.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
Symptom Matrix Chart (Cont'd)
EC-57
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/