Description for Work Flow
STEP DESCRIPTION
STEP IGet detailed information about the conditions and the environment when the incident/symptom occurred using the
``DIAGNOSTIC WORKSHEET'' as shown on EC-43.
STEP IIBefore con®rming the concern, check and write down (print out using CONSULT) the Diagnostic Trouble Code
(DTC), then erase the code. Refer to EC-30.
Study the relationship between the cause, speci®ed by DTC, and the symptom described by the customer. (The
``Symptom Matrix Chart'' will be useful. Refer to EC-48.)
STEP IIITry to con®rm the symptom and under what conditions the incident occurs.
The ``DIAGNOSTIC WORK SHEET'' is useful to verify the incident. Connect CONSULT to the vehicle in DATA
MONITOR (AUTO TRIG) mode and check real time diagnosis results.
If the incident cannot be veri®ed, perform INCIDENT SIMULATION TESTS. Refer to GI section.
If the malfunction code is detected, skip STEP IV and perform STEP V.
STEP IVTry to detect the Diagnostic Trouble Code (DTC) by driving in (or performing) the ``DTC CONFIRMATION PROCE-
DURE''. Check and read the DTC by using CONSULT.
During the DTC veri®cation, be sure to connect CONSULT to the vehicle in DATA MONITOR (AUTO TRIG) mode
and check real time diagnosis results.
If the incident cannot be veri®ed, perform INCIDENT SIMULATION TESTS. Refer to GI section.
In case the ``DTC CONFIRMATION PROCEDURE'' is not available, perform the ``OVERALL FUNCTION CHECK''
instead. The DTC cannot be displayed by this check, however, this simpli®ed ``check'' is an effective alternative.
The ``NG'' result of the ``OVERALL FUNCTION CHECK'' is the same as the DTC detection.
STEP VTake the appropriate action based on the results of STEP I through IV.
If the malfunction code is indicated, proceed to TROUBLE DIAGNOSIS FOR DTC XX.
If the normal code is indicated, proceed to the BASIC INSPECTION. Refer to EC-46. Then perform inspections
according to the Symptom Matrix Chart. Refer to EC-48.
STEP VIIdentify where to begin diagnosis based on the relationship study between symptom and possible causes. Inspect
the system for mechanical binding, loose connectors or wiring damage using (tracing) ``Harness Layouts''.
Gently shake the related connectors, components or wiring harness with CONSULT set in ``DATA MONITOR
(AUTO TRIG)'' mode.
Check the voltage of the related ECM terminals or monitor the output data from the related sensors with CON-
SULT. Refer to EC-54.
The ``DIAGNOSTIC PROCEDURE'' in EC section contains a description based on open circuit inspection. A short
circuit inspection is also required for the circuit check in the DIAGNOSTIC PROCEDURE. For details, refer to GI
section (``Circuit Inspection'', ``HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENT'').
Repair or replace the malfunction parts.
STEP VIIOnce you have repaired the circuit or replaced a component, you need to run the engine in the same conditions
and circumstances which resulted in the customer's initial complaint.
Perform the ``DTC CONFIRMATION PROCEDURE'' and con®rm the normal code (Diagnostic trouble code No. 55)
is detected. If the incident is still detected in the ®nal check, perform STEP VI by using a different method from the
previous one.
Before returning the vehicle to the customer, be sure to erase the unnecessary (already ®xed) DTC in ECM. (Refer
to EC-30.)
TROUBLE DIAGNOSIS Ð Work Flow
EC-45
Basic Inspection
Precaution:
Perform Basic Inspection without electrical or mechanical
loads applied;
+Headlamp switch is OFF,
+Air conditioner switch is OFF,
+Rear defogger switch is OFF,
+Steering wheel is in the straight-ahead position, etc.
BEFORE STARTING
1. Check service records for any recent
repairs that may indicate a related
problem, or the current need for sched-
uled maintenance.
2. Open engine hood and check the fol-
lowing:
+Harness connectors for improper con-
nections
+Vacuum hoses for splits, kinks, or
improper connections
+Wiring for improper connections,
pinches, or cuts
3. Using priming pump, bleed air from fuel
system. Refer to ``DRAINING WATER'',
``Checking and Replacing Fuel Filter
and Draining Water'' of ``ENGINE
MAINTENANCE'' in MA section.
CONNECT CONSULT TO THE VEHICLE.
Connect ``CONSULT'' to the data link con-
nector for CONSULT and select
``ENGINE'' from the menu. Refer to
EC-36.
DOES ENGINE START?
Ye s
cNo
Turn ignition switch OFF,
wait 5 seconds and then
start engine. If engine fails
to start, check diagnostic
trouble code (DTC).
Run engine for 10 minutes.
CHECK IDLE SPEED.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Read engine idle speed in ``DATA
MONITOR'' mode with CONSULT.
--------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------
Check idle speed using tachom-
eter tester.
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
775 25 rpm
(Go tojAon next page.)
SEF142I
SEF670V
SEF669V
SEF714V
SEF671V
.
.
.
.
.
TROUBLE DIAGNOSIS Ð Basic Inspection
EC-46
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
Start signal circuit open, shortjjEC-163 Start control does not function.
Neutral position switch circuitopen, shortjjj
EC-170
ground shortjj
Accelerator position switch (Idle) cir-
cuitopen, ground shortjj j
EC-165
shortjjj jjAccelerator position sensor NG
signal is output.
Accelerator position switch (Full) cir-
cuitopen, shortjjj jjEC-165
Ignition switch circuitopenj jjj
EC-63
shortEngine does not stop.
Power supply for ECM circuitopenjjj
EC-63
shortjj
Throttle control solenoid valve circuitopen, short
EC-156Does not operate.
ground shortjj jDoes not stop operating.
EGRC-solenoid valve A, B circuitopen, short
EC-156
ground shortjDoes not stop operating.
Glow relay circuitopenjjjjj
EC-151Glow lamp does not turn on.
shortGlow lamp does not turn off.
ECCS relay (Self-shutoff) circuitopenjjjj
EC-63
shortjjGround short makes engine
unable to stop.
ECM, Connector circuit open, shortjjjjjjjjjjjjj jjjjjjjjjjjjEC-111
Air conditioner relay circuitopen
EC-187Air conditioner does not operate.
shortAir conditioner does not stop
operating.
Air conditioner switch circuitopen, ground short
EC-187Air conditioner does not stop
operating.
shortAir conditioner does not work.
TROUBLE DIAGNOSIS Ð General Description
Symptom Matrix Chart (Cont'd)
EC-50
CONSULT Reference Value in Data Monitor
Mode
Remarks:
+Speci®cation data are reference values.
+Speci®cation data are output/input values which are detected or supplied by the ECM at the connector.
* Speci®cation data may not be directly related to their components signals/values/operations.
MONITOR ITEM CONDITION SPECIFICATION
CKPSzRPM (TDC)
+Tachometer: Connect
+Run engine and compare tachometer indication with the CONSULT value.Almost the same speed as the CON-
SULT value. CKPSzRPM (REF)
CMPSzRPM-PUMP
COOLAN TEMP/S+Engine: After warming up More than 70ÉC (158ÉF)
VHCL SPEED SE+Turn drive wheels and compare speedometer indication with the CONSULT
valueAlmost the same speed as
the CONSULT value
FUEL TEMP SEN+Engine: After warming up More than 40ÉC (104 ÉF)
ACCEL POS SEN+Ignition switch: ON
(Engine stopped)Accelerator pedal: released 0.40 - 0.60V
Accelerator pedal: depressed Approx. 4.0V
FULL ACCEL SW+Ignition switch: ON
(Engine stopped)Accelerator pedal: depressed ON
Except above OFF
ACCEL SW (FC)+Ignition switch: ON
(Engine stopped)Accelerator pedal: released CLOSE
Accelerator pedal: slightly open OPEN
OFF ACCEL SW+Ignition switch: ON
(Engine stopped)Accelerator pedal: released ON
Accelerator pedal: slightly open OFF
C/SLEEV POS/S+Engine: After warming up 1.0 - 3.5V
BATTERY VOLT+Ignition switch: ON (Engine stopped) 11 - 14V
P/N POSI SW+Ignition switch: ONShift lever: Neutral/Park ON
Except above OFF
START SIGNAL+Ignition switch: ON®START®ON OFF®ON®OFF
AIR COND SIG+Engine: After warming up, idle the
engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
IGN SW+Ignition switch: ON®OFF ON®OFF
WARM UP SW+Ignition switch: ONHeat up switch: ON ON
Heat up switch: OFF OFF
MAS AIR/FL SE+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ``N''
+No-loadIdle 1.6 - 2.0V
ACT INJ TIMG+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle þ9.5 to þ12.0É
2,000 rpm þ10.0 to þ15.5É
INJ TIMG C/V+Engine: After warming up, idle the engine. Approx. 50%
DECELER F/CUT+Engine: After warming upIdle OFF
When accelerator pedal is released
quickly with engine speed at 3,000 rpm
or more.ON
FUEL CUT S/V+Ignition switch: ON®OFF ON®OFF
GLOW RLY+Refer to EC-151.
TROUBLE DIAGNOSIS Ð General Description
EC-51
MONITOR ITEM CONDITION SPECIFICATION
COOLING FAN+When cooling fan is stopped. OFF
+When cooling fan operates. ON
I/C FAN RLY+When charge air cooler fan is stopped. OFF
+When charge air cooler fan operates. ON
EGRC SOL/V A+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle ON
Revving engine from idle to 3,750 rpm OFF
EGRC SOL/V B+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle ON
Revving engine from idle to 2,600 rpm OFF
THROT RLY+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle ON
Revving engine from idle to 2,500 rpm OFF
TROUBLE DIAGNOSIS Ð General Description
CONSULT Reference Value in Data Monitor
Mode (Cont'd)
EC-52
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
8 G/ORCharge air cooler fan
relayEngine is running.
Charge air cooler fan is not operating.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Charge air cooler fan is operating.0-1V
10 P Fuel temperature sensor Engine is running.
Approximately 0 - 4.8V
Output voltage varies with
fuel temperature.
14 L Cooling fan relayEngine is running.
Cooling fan is not operating.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Cooling fan is operating.0-1V
15 Y/L Air conditioner relayEngine is running.
Air conditioner switch is ``OFF''.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Both air conditioner switch and blower fan
switch are ``ON''.
(Compressor is operating.)0-1V
16 L/W Glow lampIgnition switch ``ON''
Glow lamp is ``ON''.0 - 1.5V
Ignition switch ``ON''
Glow lamp is ``OFF''.BATTERY VOLTAGE
(11 - 14V)
18 G Malfunction indicator lampIgnition switch ``ON''
0 - 1.5V
Engine is running.
Idle speedBATTERY VOLTAGE
(11 - 14V)
19 LG/REngine coolant tempera-
ture sensorEngine is running.
Approximately 0 - 4.8V
Output voltage varies with
engine coolant tempera-
ture.
20 R/W Start signalIgnition switch ``ON''
Approximately 0V
Ignition switch ``START''
BATTERY VOLTAGE
(11 - 14V)
21 LG/B Air conditioner switchEngine is running.
Air conditioner switch is ``OFF''.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Both air conditioner switch and blower fan
switch are ``ON''.
(Compressor is operating.)Approximately 0V
TROUBLE DIAGNOSIS Ð General Description
ECM Terminals and Reference Value (Cont'd)
EC-56
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
34 W Needle lift sensorEngine is running.
(Warm-up condition)
Idle speedApproximately 0V
SEF718V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 0V
SEF719V
35 R Mass air ¯ow sensorEngine is running.(Warm-up condition)
Idle speed1.6 - 2.0V
36 LGCharge air temperature
sensorEngine is running.
Approximately 0 - 4.8V
Output voltage varies with
charge air temperature.
37 P/B A/T signal No. 2Engine is running.
Idle speed6-8V
38 B/Y Ignition switchIgnition switch ``OFF''
0V
Ignition switch ``ON''
BATTERY VOLTAGE
(11 - 14V)
39
43B ECCS groundEngine is running.
Idle speedEngine ground
(Probe this terminal with
@tester probe when
measuring.)
TROUBLE DIAGNOSIS Ð General Description
ECM Terminals and Reference Value (Cont'd)
EC-58
Mass Air Flow Sensor (MAFS)
COMPONENT DESCRIPTION
The mass air ¯ow sensor is placed in the stream of intake air. It
measures the intake air ¯ow rate by measuring a part of the entire
intake air ¯ow. It consists of a hot wire that is supplied with electric
current from the ECM. The temperature of the hot wire is controlled
by the ECM a certain amount. The heat generated by the hot wire
is reduced as the intake air ¯ows around it. The more air, the
greater the heat loss.
Therefore, the ECM must supply more electric current to the hot
wire as air ¯ow increases. This maintains the temperature of the hot
wire. The ECM detects the air ¯ow by means of this current change.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS AIR/FL SE+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle 1.6 - 2.0V
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values, and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC voltage)
35 R Mass air ¯ow sensorEngine is running.
(Warm-up condition)
Idle speed1.6 - 2.0V
50 B Sensors' groundEngine is running.
(Warm-up condition)
Idle speedApproximately 0V
ON BOARD DIAGNOSIS LOGIC
Diagnostic
Trouble
Code No.Malfunction is detected when ...Check Items
(Possible Cause)
12+An excessively high or low voltage from the sensor is
sent to ECM.+Harness or connectors
(The sensor circuit is open or shorted.)
+Mass air ¯ow sensor
SEF734V
TROUBLE DIAGNOSIS FOR ``MASS AIR FLOW SEN'' (DTC 12)
EC-74