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 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 341 of 1833

CONSULT-II Reference Value in Data Monitor
Mode
Remarks:
ISpecification data are reference values.
I Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
MONITOR ITEM CONDITION SPECIFICATION
CKPS×RPM (TDC) ITachometer: Connect
I Run engine and compare the CONSULT-II value with tachometer indication. Almost the same speed as the
tachometer indication.
CMPS×RPM-PUMP
COOLAN TEMP/S IEngine: After warming up More than 70ÉC (158ÉF)
VHCL SPEED SE ITurn drive wheels and compare the CONSULT-II value with speedometer indication. Almost the same speed as the
speedometer indication
FUEL TEMP SEN IEngine: After warming up More than 40ÉC (104ÉF)
ACCEL POS SEN I
Ignition switch: ON
(Engine stopped) Accelerator pedal: fully released
0.40 - 0.60V
Accelerator pedal: fully depressed Approx. 4.5V
FULL ACCEL SW I
Ignition switch: ON
(Engine stopped) Accelerator pedal: fully depressed ON
Except above
OFF
ACCEL SW (FC) I
Ignition switch: ON
(Engine stopped) Accelerator pedal: fully released
CLOSE
Accelerator pedal: slightly open OPEN
OFF ACCEL SW I
Ignition switch: ON
(Engine stopped) Accelerator pedal: fully released
ON
Accelerator pedal: slightly open OFF
SPILL/V IEngine: After warming up Approx. 13ÉCA
BATTERY VOLT IIgnition switch: ON (Engine stopped) 11 - 14V
P/N POSI SW IIgnition switch: ON Shift lever: Park/Neutral
ON
Except above OFF
START SIGNAL IIgnition switch: ON ,START ,ON OFF ,ON ,OFF
AIR COND SIG I
Engine: After warming up, idle the
engine Air conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)
ON
BRAKE SW IIgnition switch: ON Brake pedal: depressed ON
Brake pedal: released OFF
IGN SW IIgnition switch: ON ,OFF ON ,OFF
WARM UP SW IIgnition switch: ON Heat up switch: ON ON
Heat up switch: OFF OFF
MAS AIR/FL SE I
Engine: After warming up
I Air conditioner switch: OFF
I Shift lever: Neutral position
I No-load Idle 1.6 - 2.0V
DECELER F/CUT IEngine: After warming up Idle OFF
INJ TIMG C/V IEngine: After warming up, idle the engine. Approx. 50 - 70%
AIR COND RLY I
Engine: After warming up, idle the
engine Air conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)
ON
GLOW RLY IRefer to EC-244.
COOLING FAN I
When cooling fan is stopped. OFF
I When cooling fan operates. ON
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
EC-66
http://vnx.su/
Page 342 of 1833

MONITOR ITEMCONDITION SPECIFICATION
EGR VOL CON/V I
Engine: After warming up
I Air conditioner switch: ªOFFº
I Shift lever: Neutral position
I No-load After 1 minute of idling More than 10 steps
Revving engine from idle to 3,200 rpm 0 step
VNT S/V 1 I
Engine: After warming up
I Air conditioner switch: ªOFFº
I Shift lever: Neutral position
I No-load Idle Approx. 56%
2,000 rpm Approx. 20%
BARO SEN IIgnition switch: ON Altitude
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 (4,922 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)
SWRL CON S/V 1 I
Lift up the vehicle
I Engine: After warming up let it idle for
more than 1 second.
I Air conditioner switch: ªOFFº
I No-load Shift lever: Except ªPº and ªNeutralº posi-
tions
ON
Shift lever: Neutral position OFF
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
CONSULT-II Reference Value in Data Monitor
Mode (Cont'd)
EC-67
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/
Page 344 of 1833
ECM Terminals and Reference Value
PREPARATION
1. ECM is located behind the instrument lower panel. For thisinspection, remove the driver's side instrument lower cover.
2. Remove ECM harness protector.
3. Perform all voltage measurements with the connector con- nected. Extend tester probe as shown to perform tests easily.
IOpen harness securing clip to make testing easier.
I Use extreme care not to touch 2 pins at one time.
I Data is for comparison and may not be exact.
Be sure ECM unit is properly grounded before checking.
MEC020E
AEC913
SEF367I
SEF665S
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONZD30DDTi
EC-69
http://vnx.su/