
ENGINE RELATED ITEMS
Detected items
(Screen terms for
CONSULT-II, ªSELF-DIAG
RESULTSº mode)Malfunction is detected when ...
Atmospheric pressure
sensor *5
(Ð) *3
lAn excessively high or low voltage from the sensor is detected by the ECM.
Glow relay circuit
(GLOW RELAY)
lGlow relay circuit is open or shorted.
ECM
(Ð)*3
lECM reference voltage (2.5V) is excessively high or low.
Air conditioner relay circuit
(Ð)*3
lAir conditioner relay circuit is shorted.
EGRC-solenoid valve A
(EGR SYS)
lEGRC-solenoid valve A is open or shorted.
Brake switch circuits
(Ð)*3
lBrake switch circuits are open or shorted.
ECM
(Ð)*3
lECM version number or switching function is not plausible.
ECCS-D relay circuit
(Ð)*3
lECCS-D relay shut-off time is too late.
Ignition switch ªONº signal
circuit
(Ð)*3
lIgnition switch ªONº signal evaluation circuit in ECM is malfunctioning.
Injection timing control
valve circuit
(INJ TIMING CONT/V)
lInjection timing control valve circuit is open or shorted.
Camshaft position sensor
(PUMP)*4
(Ð)*3
lAn improper signal is calculated by the ECM.
Abbreviations for Quick Reference of ªDIAGNOSTIC TROUBLE CONFIRMATION PROCEDUREº
IGN: ON : Turning the ignition switch ON is required for checking the function of the sensor, switch, solenoid and circuit.
RUNNING : Running engine is required for checking the function of the sensor, switch, solenoid and circuit.
LIFTING : Lifting up the vehicle, running engine and spinning wheels are required.
DRIVING : Driving the vehicle in the specified pattern is required.
Abbreviations for Quick Reference of ªOVERALL FUNCTION CHECKº
IGN: ON : Turning the ignition switch ON is required for the ECM to detect a malfunction (if one exists).
RUNNING : Running engine is required for the ECM to detect a malfunction (if one exists).
LIFTING : Lifting up the vehicle, running engine and spinning wheels are required for the ECM to detect a malfunction (if one
exists).
DRIVING : Driving the vehicle in the specified pattern is required for the ECM to detect a malfunction (if one exists).
TROUBLE DIAGNOSIS Ð General DescriptionCD20T
Diagnostic Trouble Chart (Cont'd)
EC-43

Ð: Not applicable
Check Items
(Possible Cause)*1
Confirmation
Procedure
Quick Ref.*2
Overall Func-
tion CheckMI
IlluminationReference
Page
lECM
IGN: ON Ð Ð EC-CD-86
lHarness or connectors
(The glow relay circuit is open or shorted.)
lGlow relayIGN: ON Ð Ð EC-CD-118
lECM
IGN: ON Ð Ð EC-CD-86
lHarness or connectors
(The air conditioner relay circuit is open or shorted.)
lAir conditioner relayIGN: ON Ð Ð EC-CD-126
lHarness or connectors
(The EGRC-solenoid valve A circuit is open or shorted.)
lEGRC-solenoid valveRUNNING Ð Lighting up EC-CD-129
lHarness or connectors
(Brake switch circuits are open or shorted.)
lBrake lamp switch
lRDNT brake switchRUNNING Ð Lighting up EC-CD-136
lECM
IGN: ON Ð Ð EC-CD-86
lHarness or connectors
(The ECCS-D relay circuit is shorted.)
lECCS-D relay
lECMIGN: ON Ð Lighting up EC-CD-86
lECM
IGN: ON Ð Lighting up EC-CD-86
lHarness or connectors
(The injection timing control valve circuit is open or
shorted.)
lInjection timing control valveIGN: ON Ð Lighting up EC-CD-82
lECM
lNeedle lift sensor
lLow battery voltageRUNNING Ð Lighting up EC-CD-97
*1:lThis is Quick Reference of ªDIAGNOSTIC TROUBLE CONFIRMATION PROCEDUREº.
Details are described in each specific TROUBLE DIAGNOSIS.
*2:
lThe ªOVERALL FUNCTION CHECKº is a simplified and effective way to inspect a component or circuit.
In some cases, the ªOVERALL FUNCTION CHECKº is used rather than a ªDIAGNOSTIC TROUBLE CONFIRMATION PRO-
CEDUREº.
When no DIAGNOSTIC TROUBLE CONFIRMATION PROCEDURE is available, the ªNGº result of the OVERALL FUNCTION
CHECK can be considered to mean the same as a malfunction item detection.
lDuring an ªNGº OVERALL FUNCTION CHECK, the malfunction item might not be confirmed.lThis is Quick Reference of ªOVERALL FUNCTION CHECKº.
Details are described in each specific TROUBLE DIAGNOSIS.
*3: CONSULT-II may not detect, but self-diagnostic results are available with MI.
*4: Imaginary sensor, which produces secondary engine revolution signal using needle lift sensor pulse.
*5: The atmospheric pressure sensor is located inside the ECM and is not replaceable.
TROUBLE DIAGNOSIS Ð General DescriptionCD20T
Diagnostic Trouble Chart (Cont'd)
EC-44

ENGINE RELATED ITEMS
Detected items
(Screen terms for
CONSULT-II, ªSELF-DIAG
RESULTSº mode)Malfunction is detected when ...
MI
(Ð)*3
lMI (malfunction indicator) circuit is open or shorted.
GLOW LAMP CIRCUIT
(Ð)*3
lGlow lamp circuit is open or shorted.
Abbreviations for Quick Reference of ªDIAGNOSTIC TROUBLE CONFIRMATION PROCEDUREº
IGN: ON : Turning the ignition switch ON is required for checking the function of the sensor, switch, solenoid and circuit.
RUNNING : Running engine is required for checking the function of the sensor, switch, solenoid and circuit.
LIFTING : Lifting up the vehicle, running engine and spinning wheels are required.
DRIVING : Driving the vehicle in the specified pattern is required.
Abbreviations for Quick Reference of ªOVERALL FUNCTION CHECKº
IGN: ON : Turning the ignition switch ON is required for the ECM to detect a malfunction (if one exists).
RUNNING : Running engine is required for the ECM to detect a malfunction (if one exists).
LIFTING : Lifting up the vehicle, running engine and spinning wheels are required for the ECM to detect a malfunction (if one
exists).
DRIVING : Driving the vehicle in the specified pattern is required for the ECM to detect a malfunction (if one exists).
TROUBLE DIAGNOSIS Ð General DescriptionCD20T
Diagnostic Trouble Chart (Cont'd)
EC-45

SYSTEM Ð Engine control module systemMalfunction
SYMPTOM
Reference page Feature of symptom
Check point
HARD/NO START/
RESTART (EXCP. HA) ENGINE STALL HESITATION/SURGING/FLAT SPOT SPARK 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 illuminates.
Can be detected by CONSULT-II?
Fuel cut
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 DECELERATINGBLACK SMOKE WHITE SMOKE
New CT/CS AA AB AC AD AE AF AG AH AJ AK AL AM AP HAEngine control moduleMass air flow sensor circuitopen, ground shortqqq q
EC-CD-62
shortqqq
Engine coolant temperature sensor
circuitopen, shortqqq qqq qqEC-CD-66Compensation according to
engine coolant temperature
does not function.
Vehicle speed sensor circuit or ABS
actuator and electric unit (control
unit) circuitopen, shortqqEC-CD-70
Control sleeve position sensor cir-
cuitopen, shortqqq qqqEC-CD-74
Electric governor circuitopen, ground shortq qqq qqq
EC-CD-78
shortqq
Injection timing control valve circuitopen, shortqqqq
EC-CD-82Injection timing cannot be
controlled.
ground shortqqq
Needle lift sensor circuit open, shortqqqqEC-CD-97
Fuel cut solenoid valve circuitopen, ground shortq qqq qqq
EC-CD-100
shortqqqEngine runs on after turning
ignition switch OFF.
Fuel temperature sensor circuit open, shortqq qq qq q qq qEC-CD-104Compensation for amount
of fuel injected according
to fuel temperature does
not function.
Accelerator position sensor circuit open, shortqqq qqEC-CD-108
Crankshaft position sensor (TDC)
circuitopen, shortqq qq
EC-CD-114
noiseqqq qq
TROUBLE DIAGNOSIS Ð General DescriptionCD20T
Symptom Matrix Chart (Cont'd)
EC-48

SYSTEM Ð Engine control module systemMalfunction
SYMPTOM
Reference page Feature of symptom
Check point
HARD/NO START/
RESTART (EXCP. HA) ENGINE STALL HESITATION/SURGING/FLAT SPOT SPARK 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 illuminates.
Can be detected by CONSULT-II?
Fuel cut
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 DECELERATINGBLACK SMOKE WHITE SMOKE
New CT/CS AA AB AC AD AE AF AG AH AJ AK AL AM AP HAEngine control moduleStart signal circuit open, shortqqEC-CD-145 Start control does not function.
Air conditioner switch circuitopen, ground short
EC-CD-126Air conditioner does not stop
operating.
shortAir conditioner does not work.
Accelerator position switch (Idle)
circuitopen, ground shortqq q qq
EC-CD-108
shortqqq qqAccelerator position sensor NG
signal is output.
Ignition switch circuit (ON signal)openq qqq
EC-CD-59
shortEngine does not stop.
Power supply for ECM circuitopenqqq
EC-CD-59
shortqq
EGRC-solenoid valve circuitopen, shortqq
EC-CD-129
ground shortqqqDoes not stop operating.
Glow relay circuitopenqqqq q qq
EC-CD-118Glow lamp does not turn on.
shortqqGlow lamp does not turn off.
Engine control module relay (Self-
shutoff) circuitopenqqqq
EC-CD-59
shortqq qGround short makes engine
unable to stop.
Air conditioner relay circuitopen
EC-CD-126Air conditioner does not oper-
ate.
shortqqAir conditioner does not stop
operating.
Brake switch circuitsopenq
EC-CD-136
shortq
ECM, Connector circuit open, shortqqqqqqqqqqqqq qqqqqqqqqqqqEC-CD-86
TROUBLE DIAGNOSIS Ð General DescriptionCD20T
Symptom Matrix Chart (Cont'd)
EC-49

Major Sensor Reference Graph in Data
Monitor Mode
The following are the major sensor reference graphs in ªDATA MONITORº mode.
(Select ªHI SPEEDº in ªDATA MONITORº with CONSULT-II.)
ACCEL POS SEN, C/SLEEV POS/S, ACT INJ TIMG
Below is the data for ªACCEL POS SENº, ªC/SLEEV POS/Sº and ªACT INJ TIMGº when revving engine
quickly up to 3,000 rpm under no load after warming up engine sufficiently.
Each value is for reference, the exact value may vary.
NEF780
lªACCEL POS SENº should increase
while depressing the accelerator
pedal and should decrease while
releasing it.
lªC/SLEEV POS/Sº should increase
when depressing the accelerator
pedal and should decrease when the pedal is
released.
lªACT INJ TIMGº should increase
when depressing the accelerator
pedal and should decrease when
the pedal is released.
ACT INJ TIMG
13:22-00º09
+04º95 16:06 x0.1V-00º09
+04º95 16:06 x0.1V-00º09
+04º95
TROUBLE DIAGNOSIS Ð General DescriptionCD20T
EC-51

TER-
MINAL
NO.WIRE
COLORITEM CONDITIOND ATA
(DC Voltage and
Pulse Signal)
204 L/W Air conditioner relayEngine is running.
Both A/C switch and blower switch are
ªONºApproximately 0.4V
Engine is running.
A/C switch is ªOFFºBATTERY VOLTAGE
(11 - 14V)
208 P EGRC-solenoid valve AEngine is running.
(Warm-up condition)
Idle speedBATTERY VOLTAGE (11
- 14V)
Engine is running.
(Warm-up condition)
Engine speed is 2,800 rpmApproximately 0.3V
214 W/R Glow relay Refer to ªGlow control Systemº.
215 OR/L Malfunction indicatorIgnition switch ªONº
Approximately 1.0V
Engine is running.
Idle speedBATTERY VOLTAGE
(11 - 14V)
218 ORMass air flow sensor
groundEngine is running.
Idle speedApproximately 0V
219 LG/RCooling fan relay
(Low speed)Engine is running.
Cooling fan is not operating.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Cooling fan is operating.Approximately 0.4V
220 LGCooling fan relay
(High speed)Engine is running.
Cooling fan is not operating.
Cooling fan is operating at low speed.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Cooling fan is operating at high speed.Approximately 0.5V
221 P/L Glow lampIgnition switch ªONº
Glow lamp is ªONº.Approximately 1.0V
Ignition switch ªONº
Glow lamp is ªOFFºBATTERY VOLTAGE
(11 - 14V)
223 W/LMass air flow sensor
power supplyIgnition switch ªONº
Approximately 5V
224 L/W Mass air flow sensorEngine is running.
(Warm-up condition)
Idle speed1.9 - 2.3V
Engine is running.
(Warm-up condition)
Engine speed is 2,000 rpm2.5 - 2.9V
TROUBLE DIAGNOSIS Ð General DescriptionCD20T
ECM Terminals and Reference Value (Cont'd)
EC-54

TER-
MINAL
NO.WIRE
COLORITEM CONDITIOND ATA
(DC Voltage and
Pulse Signal)
320 WControl sleeve position
sensor power supplyEngine is running.
Idle speedApproximately 2.6V
SEF559S
321 BControl sleeve position
sensor groundEngine is running.Idle speedApproximately 2.6V
SEF560S
322 RControl sleeve position
sensor (Reference sig-
nal)Engine is running.(Warm-up condition)
Idle speedApproximately 2.6V
SEF561S
325 W/GEngine control module
relay (Self-shutoff)Engine is running.
Ignition switch ªLOCKº
For a few seconds after turning ignition
switch to the ªLOCKº position0-1V
Ignition switch ªLOCKº
Following a few seconds delay after turning
ignition switch to the ªLOCKº positionBATTERY VOLTAGE
(11 - 14V)
331 ORCrankshaft position sen-
sor (TDC) groundEngine is running.
Idle speedApproximately 0V
333 BNeedle lift sensor
groundIgnition switch ªONº
Approximately 0V
334
335
436B Sensors' groundEngine is running.
Idle speedApproximately 0V
TROUBLE DIAGNOSIS Ð General DescriptionCD20T
ECM Terminals and Reference Value (Cont'd)
EC-55