
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNAL+Engine: After warming up, idle
the engineSteering wheel in neutral position
(forward direction)OFF
The steering wheel is turned ON
LOAD SIGNAL+Engine: runningRear window defogger or headlamp
ªONºON
Except the above OFF
IGNITION SW+Ignition switch: ON®OFF ON®OFF
INJ PULSE-B1+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ªNº
+No-loadIdle 2.4 - 3.2 msec
2,000 rpm 1.9 - 2.8 msec
IGN TIMING+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ªNº
+No-loadIdle 15É BTDC
2,000 rpm Approx. 40É BTDC
CAL/LD VALUE+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ªNº
+No-loadIdle Not used
2,500 rpm Not used
ABSOL TH´P/S+Engine: Idle Throttle valve fully closed 0.0É
+Ignition switch: ON
(Engine stopped)Throttle valve fully opened Approx. 80É
MASS AIRFLOW+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: N
+No-loadIdle 2.5 - 5.0 g´m/s
2,500 rpm 7.1 - 12.5 g´m/s
IACV-AAC/V+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ªNº
+No-loadIdle 5 - 25 steps
2,000 rpm Ð
PURG VOL C/V+Engine: After warming up
+No-loadIdle 0%
Revving engine Ð
EGR VOL CON/V
(where fitted)+Engine: After warming up
+Shift lever: ªNº
+No-loadIdle 0 step
Revving engine up to 3,000 rpm
quickly10 - 55 steps
AIR COND RLY+Air conditioner switch: OFF®ON OFF®ON
FUEL PUMP RLY+Ignition switch is turned to ON (Operates for 1 second)
+Engine running and cranking
+When engine is stopped (stops in 1.5 seconds)ON
+Except as shown above OFF
COOLING FAN+After warming up engine, idle
the engine.
+Air conditioner switch: OFFEngine coolant temperature is 94ÉC
(201ÉF) or lessOFF
Engine coolant temperature is
between 95ÉC (203ÉF) and 104ÉC
(219ÉF)LOW
Engine coolant temperature is 105ÉC
(221ÉF) or moreHIGH
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONSR20DE
CONSULT-II Reference Value in Data Monitor Mode (Cont'd)
EC-653

ECM HARNESS CONNECTOR TERMINAL LAYOUTNLEC1375S02
SEF970W
ECM INSPECTION TABLENLEC1375S03Specification data are reference values and are measured between
each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
3 W/RHeated oxygen sensor
2 heater (rear)[Engine is running]
+Engine speed is below 3,600 rpm
+After driving for 2 minutes at a speed of 70
km/h (43 MPH) or moreApproximately 0.7V
[Ignition switch ªONº]
+Engine stopped
+Engine speed is above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
4LHeated oxygen sensor
1 heater (front)[Engine is running]
+Engine speed is below 3,200 rpmApproximately 0V
[Engine is running]
+Engine speed is above 3,200 rpmBATTERY VOLTAGE
(11 - 14V)
6
7
15
16BR
LG
GY/L
ORIACV-AAC valve[Engine is running]
+Warm-up condition
+Idle speed0.1 - 14V
8
9
17
18SB
W/B
R/W
G/REGR volume control
valve (where fitted)[Engine is running]
+Warm-up condition
+Rev engine from 2,000 to 4,000 rpm0 - 14V
10 Y/L CVT signal No. 3[Engine is running]
+Idle speedApproximately 0V
12 LG/RB Cooling fan relay (High)[Engine is running]
+Cooling fan is not operatingBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Cooling fan (High) is operating0 - 0.6V
13 LG/R Cooling fan relay[Engine is running]
+Cooling fan is not operatingBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Cooling fan is operatingApproximately 0V
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONSR20DE
ECM Terminals and Reference Value (Cont'd)
EC-659

DescriptionNLEC1748The specification (SP) value indicates the tolerance of the value that is displayed in ªDATA MONITOR (SPEC)º
mode of CONSULT-II during normal operation of the Engine Control System. When the value in ªDATA MONI-
TOR (SPEC)º mode is within the SP value, the Engine Control System is confirmed OK. When the value in
ªDATA MONITOR (SPEC)º mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
+B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)
+A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
+MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing ConditionNLEC1749+Vehicle driven distance: More than 5,000 km (3,107 miles)
+Barometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm2, 14.25 - 15.12 psi)
+Atmospheric temperature: 20 - 30ÉC (68 - 86ÉF)
+Engine coolant temperature: 75 - 95ÉC (167 - 203ÉF)
+Transmission: Warmed-up*1
+Electrical load: Not applied*2
+Engine speed: Idle
*1: For after the engine is warmed up to normal operating temperature, drive vehicle until ªFLUID TEMP SEº
(CVT fluid temperature sensor signal) indicates less than 0.9V.
*2: Rear window defogger switch, air conditioner switch, lighting switch are ªOFFº. Cooling fans are not oper-
ating. Steering wheel is straight ahead.
SEF601Z
Inspection ProcedureNLEC1750NOTE:
Perform ªDATA MONITOR (SPEC)º mode in maximum scale dis-
play.
1. Perform ªBasic Inspectionº, EC-623.
2. Confirm that the testing conditions indicated above are met.
3. Select ªB/FUEL SCHDLº, ªA/F ALPHA-B1º and ªMAS A/F
SE-B1º in ªDATA MONITOR (SPEC)º mode with CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to ªDiagnostic Procedureº, EC-667.
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUESR20DE
Description
EC-666

Fail-safe ModeNLEC1399
Detected items Engine operating condition in fail-safe mode
Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning ignition switch
ªONº or ªSTARTº.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided (CONSULT-II
display)
Just as ignition switch is turned ON or Start 40ÉC (104ÉF)
More than approx. 4 minutes after ignition ON or
Start80ÉC (176ÉF)
Except as shown above40 - 80ÉC (104 - 176ÉF)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates
while the engine is running.
SEF013Y
DTC Confirmation ProcedureNLEC1400NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 5 seconds.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-698 .
With GST
Follow the procedure ªWith CONSULT-IIº above.
No Tools
1) Turn ignition switch ªONº and wait at least 5 seconds.
2) Turn ignition switch ªOFFº, wait at least 10 seconds and then
turn ªONº.
3) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º with
ECM.
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-698.
DTC P0115 ENGINE COOLANT TEMPERATURE SENSOR (ECTS)
(CIRCUIT)
SR20DE
Fail-safe Mode
EC-695

DescriptionNLEC1768SYSTEM DESCRIPTIONNLEC1768S01
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor Engine speed
Idle air
controlIACV-AAC valve Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Throttle position sensor Throttle position
Park/neutral position (PNP) switch Park/neutral position
Air conditioner switch Air conditioner operation
Power steering oil pressure switch Power steering load signal
Battery Battery voltage
Vehicle speed sensor Vehicle speed
Intake air temperature sensor Intake air temperature
Cooling fan Cooling fan operation
Electrical load Electrical load signal
This system automatically controls engine idle speed to a specified
level. Idle speed is controlled through fine adjustment of the
amount of air which by-passes the throttle valve via IACV-AAC
valve. The IACV-AAC valve changes the opening of the air by-pass
passage to control the amount of auxiliary air. This valve is actu-
ated by a step motor built into the valve, which moves the valve in
the axial direction in steps corresponding to the ECM output sig-
nals. One step of IACV-AAC valve movement causes the respec-
tive opening of the air by-pass passage. (i.e. when the step
advances, the opening is enlarged.) The opening of the valve is
varied to allow for optimum control of the engine idling speed. The
camshaft position sensor detects the actual engine speed and
sends a signal to the ECM. The ECM then controls the step posi-
tion of the IACV-AAC valve so that engine speed coincides with the
target value memorized in ECM. The target engine speed is the
lowest speed at which the engine can operate steadily. The opti-
mum value stored in the ECM is determined by takig into consid-
eration various engine conditions, such as during warm up,
deceleration, and engine load (air conditioner, power steering and
cooling fan operation).
SEF937W
COMPONENT DESCRIPTIONNLEC1768S02IACV-AAC ValveNLEC1768S0201The IACV-AAC valve is operated by a step motor for centralized
control of auxiliary air supply. This motor has four winding phases
and is actuated by the output signals of ECM which turns ON and
OFF two windings each in sequence. Each time the IACV-AAC
valve opens or closes to change the auxiliary air quantity, the ECM
sends a pulse signal to the step motor. When no change in the
auxiliary air quantity is needed, the ECM does not issue the pulse
signal. A certain voltage signal is issued so that the valve remains
at that particular opening.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
SR20DE
Description
EC-863

System DescriptionNLEC1618COOLING FAN CONTROLNLEC1618S01
Sensor Input Signal to ECMECM func-
tionActuator
Vehicle speed sensor Vehicle speed
Cooling fan
controlCooling fan relay(s) Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch Air conditioner ªONº signal
Ignition switch Start signal
Refrigerant pressure sensor Refrigerant pressure
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refriger-
ant pressure, and air conditioner ON signal. The control system has 3-step control [HIGH/LOW/OFF].
OPERATIONNLEC1618S02
SEF771Z
CONSULT-II Reference Value in Data Monitor
Mode
NLEC1619Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
AIR COND SIG+Engine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates)ON
DTC P1217 OVERHEAT (COOLING SYSTEM)SR20DE
System Description
EC-882

MONITOR ITEM CONDITION SPECIFICATION
COOLING FAN+After warming up engine, idle
the engine.
+Air conditioner switch: OFFEngine coolant temperature is less
than 95ÉC (203ÉF)OFF
Engine coolant temperature is
95ÉC (203ÉF) and 105ÉC (221ÉF)LOW
Engine coolant temperature is
105ÉC (221ÉF) or moreHIGH
ECM Terminals and Reference ValueNLEC1769Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
12 LG/B Cooling fan relay (High)[Engine is running]
+Cooling fan is not operatingBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Cooling fan (High) is operating0 - 0.6V
13 LG/R Cooling fan relay (Low)[Engine is running]
+Cooling fan is not operatingBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
+Cooling fan is operating0 - 0.6V
On Board Diagnosis LogicNLEC1770If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
Diagnostic
Trouble Code
No.Malfunction is detected when ...Check Items
(Possible Cause)
P1217
1217+Cooling fan does not operate properly (Overheat).
+Cooling fan system does not operate properly (Over-
heat).
+Engine coolant was not added to the system using the
proper filling method.+Harness or connectors
(The cooling fan circuit is open or shorted.)
+Cooling fan
+Radiator hose
+Radiator
+Radiator cap
+Water pump
+Thermostat
For more information, refer to ªMAIN 12 CAUSES
OF OVERHEATINGº, EC-898.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in the LC-19,
ªChanging Engine Coolantº. Also, replace the engine oil.
1) Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Be sure to use
coolant with the proper mixture ratio. Refer to MA-20, ªAnti-freeze Coolant Mixture Ratioº, ªRECOM-
MENDED FLUIDS AND LUBRICANTSº.
2) After refilling coolant, run engine to ensure that no water-flow noise is emitted.
DTC P1217 OVERHEAT (COOLING SYSTEM)SR20DE
CONSULT-II Reference Value in Data Monitor Mode (Cont'd)
EC-883

SEF621W
SEF111X
SEC163BA
MEC475B
Overall Function CheckNLEC1771Use this procedure to check the overall function of the cooling fan.
During this check, a DTC might not be confirmed.
WARNING:
Never remove the radiator cap when the engine is hot. Serious
burns could be caused by high pressure fluid escaping from
the radiator.
Wrap a thick cloth around cap. Carefully remove the cap by
turning it a quarter turn to allow built-up pressure to escape.
Then turn the cap all the way off.
With CONSULT-II
1) Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is below
the proper range, skip the following steps and go to ªDiagnos-
tic Procedureº, EC-887.
2) Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to ªDiagnos-
tic Procedureº, EC-887.
3) Turn ignition switch ªONº.
4) Perform ªCOOLING FANº in ªACTIVE TESTº mode with CON-
SULT-II.
5) If the results are NG, go to ªDiagnostic Procedureº, EC-887.
Without CONSULT-II
1) Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is below
the proper range, skip the following steps and go to ªDiagnos-
tic Procedureº, EC-887.
2) Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to ªDiagnos-
tic Procedureº, EC-887.
3) Start engine.
Be careful not to overheat engine.
4) Set temperature control lever to full cold position.
5) Turn air conditioner switch ªONº.
6) Turn blower fan switch ªONº.
7) Run engine at idle for a few minutes with air conditioner oper-
ating.
Be careful not to overheat engine.
8) Make sure that cooling fan operates at low speed.
If NG, go to ªDiagnostic Procedureº, EC-887.
If OK, go to the following step.
9) Turn ignition switch ªOFFº.
10) Turn air conditioner switch and blower fan switch ªOFFº.
11) Disconnect engine coolant temperature sensor harness con-
nector.
12) Connect 150Wresistor to engine coolant temperature sensor
harness connector.
13) Restart engine and make sure that cooling fan operates at
higher speed than low speed.
Be careful not to overheat engine.
14) If NG, go to ªDiagnostic Procedureº, EC-887.
DTC P1217 OVERHEAT (COOLING SYSTEM)SR20DE
On Board Diagnosis Logic (Cont'd)
EC-884