
HOW TO SWITCH DIAGNOSTIC TEST MODES
Turn ignition switch ``ON''.
(Do not start engine.)
c
Diagnostic Test Mode I Ð BULB CHECK.
Refer to previous page.
MIL should come on.
.
OK
cNG
Check MIL circuit.
(See EC-188.)
OK
.
cNG
Repair harness or
connectors.
OK
b
cG
Start engine.
cDiagnostic Test
Mode I
Ð MALFUNC-
TION WARN-
ING.
Refer to previ-
ous page.
Data link connector for CONSULT
(Connect CHK and IGN terminals with a suitable
harness.)
MIL should go off.
cNG
Check MIL circuit and data link connector for
CONSULT circuit. (See EC-188.)
OK
.
NG
Repair harness or
connectors.
OK
Wait at least 2 seconds.
.b
Data link connector for CONSULT
(Disconnect the suitable harness between CHK
and IGN terminals.)
DIAGNOSTIC TEST MODE II
Ð SELF-DIAGNOSTIC RESULTS
.jBjA
.
.
.
.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-32

jB
m
jA
Data link connector for CONSULT
(Connect CHK and IGN terminals with a suit-
able harness.)
Wait at least 2 seconds.
Data link connector for CONSULT
(Disconnect the suitable harness between
CHK and IGN terminals.)
If the suitable harness is disconnected at this
time, the diagnostic trouble code will be
erased from the backup memory in the ECM.
+Switching the modes is not possible when the engine
is running.
+When ignition switch is turned off during diagnosis,
power to ECM will drop after approx. 5 seconds.
The diagnosis will automatically return to Diagnostic
Test Mode I..
.
.
.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-33

DIAGNOSTIC TEST MODE IÐBULB CHECK
In this mode, the MALFUNCTION INDICATOR LAMP on the instrument panel should stay ON. If it remains
OFF, check the bulb. Refer to EL section (``WARNING LAMPS AND CHIME'') or see EC-188.
DIAGNOSTIC TEST MODE IÐMALFUNCTION WARNING
MALFUNCTION
INDICATOR LAMPCondition
ONWhen the malfunction is detected or the ECM's CPU is malfunctioning. (Refer to ``MIL Illumination'' of the
``DIAGNOSTIC TROUBLE CODE INDEX'', EC-1.)
OFF No malfunction.
+These Diagnostic Trouble Code Numbers are clari®ed in Diagnostic Test Mode II (SELF-DIAGNOSTIC
RESULTS).
DIAGNOSTIC TEST MODE IIÐSELF-DIAGNOSTIC RESULTS
In this mode, a diagnostic trouble code is indicated by the number of blinks of the MALFUNCTION INDICA-
TOR LAMP as shown below.
Long (0.6 second) blinking indicates the number of ten digits, and short (0.3 second) blinking indicates the
number of single digits. For example, the malfunction indicator lamp blinks 4 times for 5 seconds (0.6 sec x
4 times) and then it blinks three times for about 1 second (0.3 sec x 3 times). This indicates the DTC ``43''
and refers to the malfunction of the accelerator position sensor circuit.
In this way, all the detected malfunctions are classi®ed by their diagnostic trouble code numbers. The DTC
``55'' refers to no malfunction. (See DIAGNOSTIC TROUBLE CODE INDEX, EC-1.)
HOW TO ERASE DIAGNOSTIC TEST MODE II (Self-diagnostic results)
The diagnostic trouble code can be erased from the backup memory in the ECM when the diagnostic test mode
is changed from Diagnostic Test Mode II to Diagnostic Test Mode I. (Refer to ``HOW TO SWITCH DIAGNOS-
TIC TEST MODES'' on previous page.)
+If the battery terminal is disconnected, the diagnostic trouble code will be lost from the backup
memory within 24 hours.
+Be careful not to erase the stored memory before starting trouble diagnoses.
+If the MIL blinks or ``NATS MALFUNCTION'' is displayed on
``SELF-DIAG RESULTS'' screen, perform self-diagnostic
results mode with CONSULT using NATS program card
(NATS-E940). Refer to EL section.
+Con®rm no self-diagnostic results of NATS is displayed
before touching ``ERASE'' in ``SELF-DIAG RESULTS'' mode
with CONSULT.
+When replacing ECM, initialisation of NATS V2.0 system
and registration of all NATS V2.0 ignition key IDs must be
carried out with CONSULT using NATS program card
(NATS-E940).
Therefore, be sure to receive all keys from vehicle owner.
Regarding the procedures of NATS initialisation and NATS
ignition key ID registration, refer to CONSULT operation
manual, NATS V2.0.
SEF212NA
SEF288Q
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-34

RELATIONSHIP BETWEEN MIL, DTC, CONSULT AND DRIVING PATTERNS
*1: When a malfunction is detected, MIL will light up.
*2: When the same malfunction is detected in two consecutive
driving patterns, MIL will stay lit up.
*3: MIL will go off after vehicle is driven three times without
any malfunctions.
*4: When a malfunction is detected for the ®rst time, the DTC
will be stored in ECM.*5: The DTC will not be displayed any longer after vehicle is
driven 40 times without the same malfunction.
(The DTC still remain in ECM.)
*6: Other screens except SELF-DIAGNOSTIC RESULTS &
DATA MONITOR (AUTO TRIG) cannot display the mal-
function. DATA MONITOR (AUTO TRIG) can display the
malfunction at the moment it is detected.
SEF659S
RUN (ON)
STOP (OFF)
ON
OFF
DISPLAY
NO
DISPLAY
DTC exists
DTC does
not exist
COUNTER Driving Pattern
Engine
(GN)
MIL
ECM Diagnostic
trouble
code
CONSULT
SELF-
DIAGNOSTIC
RESULTS
SCREEN
&
DATA MONITOR
(AUTO TRIG) SCREEN
SELF-
DIAGNOSTIC
RESULTS
SCREENNG DetectionThis driving pattern does not satisfy
self-diagnostic condition.
This driving pattern satis®es
self-diagnostic condition.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL) (Cont'd)
EC-35

Diagnostic Worksheet
There are many operating conditions that lead to the malfunction
of engine components. A good grasp of such conditions can make
troubleshooting faster and more accurate.
In general, each customer feels differently about a problem. It is
important to fully understand the symptoms or conditions for a
customer complaint.
Utilize a diagnostic worksheet like the one shown below in order to
organize all the information for troubleshooting.
WORKSHEET SAMPLE
Customer name MR/MS Model & Year VIN
Engine # Trans. Mileage
Incident Date Manuf. Date In Service Date
SymptomshStartabilityhImpossible to starthNo combustionhPartial combustion
hPartial combustion when engine is warm
hPartial combustion when engine is cool
hPossible but hard to starthOthers [ ]
hIdlinghNo fast idlehUnstablehHigh idlehLow idle
hOthers [ ]
hDriveabilityhStumblehSurgehKnockhLack of power
hOthers [ ]
hEngine stallhAt the time of starthWhile idling
hWhile acceleratinghWhile decelerating
hJust after stoppinghWhile loading
Incident occurrencehJust after deliveryhRecently
hIn the morninghAt nighthIn the daytime
FrequencyhAll the timehUnder certain conditionshSometimes
Weather conditionshNot affected
WeatherhFinehRaininghSnowinghOthers [ ]
TemperaturehHothWarmhCoolhColdhHumid ÉF
Engine conditionshColdhDuring warm-uphAfter warm-up
Engine speed
Road conditionshIn townhIn suburbshHighwayhOff road (up/down)
Driving conditionshNot affected
hAt startinghWhile idlinghAt racing
hWhile acceleratinghWhile cruising
hWhile deceleratinghWhile turning (RH/LH)
Vehicle speed
Malfunction indicator lamphTurned onhNot turned on
SEF907L
TROUBLE DIAGNOSIS Ð Introduction
EC-43

jA
CHECK INJECTION TIMING.
1. Set No. 1 piston at TDC on its com-
pression stroke.
2. Remove injection tubes and air bleeder
on the back of injection pump.
3. Set dial gauge so its indicator points to
somewhere between 1.0 and 2.0 mm
(0.039 and 0.079 in) on the scale.
4. Turn crankshaft 1 turn clockwise and
check that dial gauge indicates the
same value again.
5. Turn crankshaft counterclockwise about
100 degrees, then turn crankshaft
clockwise slowly, and set dial gauge
indicator to 0 mm at the position it
stops.
6. Turn crankshaft clockwise and set the
injection timing mark on the crankshaft
pulley to the timing indicator.
7. Read plunger lift.
Plunger lift:
0.92 0.04 mm (0.0362 0.0016 in)
+When repeating the checking, start
with step 5.
NG
cOK
+Bleed air from fuel sys-
tem.
+After this inspection,
unnecessary diagnostic
trouble code No. might
be displayed.
Erase the stored
memory in ECM.
Refer to ``ON BOARD
DIAGNOSTIC SYSTEM
DESCRIPTION'' (EC-30)
and ``HOW TO ERASE
DTC'' (EC-30).
OK
INSPECTION END
ADJUSTING
1. If plunger lift is not within the speci®ed
value, adjust by turning injection pump.
+If indication is smaller than the speci-
®ed value, turn pump body away
from engine.
+If indication is larger than the speci-
®ed value, turn pump body towards
engine.
2. Tighten injection pump securing bolts
and nuts.
Nut:
: 16-21Nzm
(1.6 - 2.1 kg-m, 12 - 15 ft-lb)
Bolt:
: 22-29Nzm
(2.2 - 3.0 kg-m, 16 - 22 ft-lb)
3. Remove dial gauge and install air
bleeder with new washer.
4. Install injection tubes.
Flare nut:
: 22-25Nzm
(2.2 - 2.5 kg-m, 16 - 18 ft-lb)
5. Bleed air from fuel system.
Refer to ``DRAINING WATER'', ``Check-
ing and Replacing Fuel Filter and
Draining Water'' of ``ENGINE MAINTE-
NANCE'' in MA section.
cGo to.
SEF672V
SEF664V
SEF673V
SEF666V
.
.
.
TROUBLE DIAGNOSIS Ð Basic Inspection
Basic Inspection (Cont'd)
EC-47

Symptom Matrix Chart
SYSTEM
Ð Basic engine
control systemSYMPTOM
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
ROUGH 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?
Fuel cutNO START (with ®rst ®ring)
NO START (without ®rst ®ring)
HARD TO START WHEN ENGINE IS COLD
HARD TO START WHEN ENGINE IS HOT
AT IDLE
DURING DRIVING
WHEN DECELERATING
BLACK SMOKE
WHITE SMOKEWarranty symptom
codeAA AB AC AD AE AF AG AH AJ AK AL AM AP HA
Injection
timingAdvancedjj
++j+jj+jEC-47
Retardedjj
++j+jj+jEC-47
Electric injection pump
mainframe
++++jjjjj+jjj++jj+j jjjÐ*1
Injection nozzlejjjjjjj
+jj j++ +EC-22 *2
Glow systemjj
++ + +EC-151
Engine body
jj
++jjj+jj j++jjj+EM sec-
tion*3
EGR system
++ +EC-156
Air cleaner and ducts
++ +jMA sec-
tion*4
+; High Possibility Item
j; Low Possibility Item
*1: Insufficient or excess amount. Governor 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 Description
EC-48

SYSTEM
Ð ECCS systemMalfunction
SYMPTOM
Reference
page Feature of symptom
Check point
HARD/NO START/
RESTART (EXCP. HA) ENGINE STALL HESITATION/SURGING/FLAT SPOT KNOCK/DETONATION
LACK OF POWER
POOR ACCELERATION
HI IDLE
LOW IDLE
ROUGH 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?
Fuel cut
NO START (with ®rst ®ring) NO START (without ®rst ®ring)
HARD TO START WHEN ENGINE IS COLD
HARD TO START WHEN ENGINE IS HOT
AT IDLE
DURING DRIVING
WHEN DECELERATINGBLACK SMOKE WHITE SMOKE
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM AP HAECCS
Camshaft position sensor (PUMP) cir-
cuitopen, shortjj
EC-69Tachometer malfunction
noisejjjj jj
Mass air ¯ow sensor circuitopen, ground shortjjj j
EC-74
shortjjj
Engine coolant temperature sensor
circuitopen, shortjjj jjj jjEC-79Compensation according to
engine coolant temperature does
not function.
Vehicle speed sensor circuit open, shortjjEC-83
Control sleeve position sensor circuit open, shortjjjjjjEC-87
Adjustment resistor circuit open, shortj j jjjj j jEC-92
Electric governor circuitopen, ground shortj jjjjjj
EC-96
shortjj
Injection timing control valve circuitopen, shortjjj
EC-101Injection timing cannot be con-
trolled.
ground shortjj
Accelerator switch (FC) circuitopen, shortjjj
EC-106
ground shortjj
Charge air temperature sensor circuit open, shortjEC-122
Needle lift sensor circuit open, shortjjjEC-126
Fuel cut solenoid valve circuitopen, ground shortj jjjj
EC-130
shortjjjEngine runs on after turning igni-
tion switch OFF.
Fuel temperature sensor circuit open, shortjj jj jj j jj jEC-135Compensation for amount of fuel
injected according to fuel tem-
perature does not function.
Accelerator position sensor circuit open, shortjjj jjEC-139
Crankshaft position sensor (TDC) cir-
cuitopen, shortjj jj
EC-144
noisejjjjj
TROUBLE DIAGNOSIS Ð General Description
Symptom Matrix Chart (Cont'd)
EC-49