Page 482 of 2053
1F2 -- 64 M161 ENGINE CONTROLS
D AEW OO M Y_2000
ENGINE COOLANT TEMPERATURE (ECT) SENSOR
YAA1F590
Engine Coolant Temperature (ECT) sensor detects coolant temperature and supplies information to the ECM. It is
composed of metal housing with two NTC resistor, 4 pin connector. The ECM provides a 5 volt signal to the ECT
sensor through a dropping resistor. When the engine is cold, the ECT sensor provides high resistance, which the ECM
detects as a high signal voltage. As the engine warms up, the sensor resistance becomes lower, and the signal voltage
drops. At normal engine operating temperature, the ECT signalwill measure about 1.5 to 2.0 volts.
The ECM uses information about coolant temperature to make the necessary calculations for:
DFuel delivery
DIgnition control
DKnock sensor system
DIdle speed
DTorque converter clutch application
DCanister purge
DCooling fan operation
DOthers
Page 484 of 2053

1F2 -- 66 M161 ENGINE CONTROLS
D AEW OO M Y_2000
KAB1F260
Failure
CodeDescriptionTrouble AreaMaintenance Hint
00
Engine coolant
temperature sensor low
voltageECT sensor short circuit to
ground or open
01
Engine coolant
temperature sensor high
voltageECT sensor short circuit to
power
DMonitoring the actual coolant
temperaturethroughscantool
02
Engine coolant
temperature sensor
plausibilityMalfunction in recognition of
ECT
When drop to about 50°C
below after warm uptemperaturethroughscantool
DInspection the ECM pin 78, 79 about
short circuit or open with bad contact
DInspection the ECT sensor
DIns
pection the ECM
06
Engine coolant
temperature insufficient
for closed loop fuel
controlMalfunction in recognition of
ECT
When minimum temperature
for lambda control after warm
up
DInspectiontheECM
Circuit Description
The ECT sensor uses a thermistor to control the signal voltage to the ECM. The ECM supplies a voltage on the signal
circuit to the sensor. When the engine coolant is cold, the resistance is high; therefore the ECT signal voltagewill be
high
Engine Coolant Temperature Sensor Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the voltage between the ECM pin No. 78 and No. 79.
Temperature (°C)
Specified Value (V)
203.57
801.22
1000.78
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M161 ENGINE CONTROLS 1F2 -- 67
D AEW OO M Y_2000
3. Turn the ignition switch to “OFF” position.
4. Disconnect the ECT sensor connector.
5. Turn the ignition switch to “ON” position.
6. Measure the resistance between the ECT sensor terminal pin No. 1 and No. 4.
Temperature (°C)
Specified Value (Ω)
202,500
80322
100185
Notice:Replace wiring and coolant temperature sensor if out of specified value.
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1F2 -- 70 M161 ENGINE CONTROLS
D AEW OO M Y_2000
Acceleration Pedal Position Sensor 1 Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the signal voltage between the ECM pin No. 47 and No. 31 while operating the accelerator pedal as follow-
ing conditions.
DNot depress the pedal (closed throttle position)
DFully depress the pedal (full throttle with kick down)
Condition of Throttle Valve
Specified Value (V)
Closed Throttle Valve0.3 ~ 0.7
Fully Depressed Throttle Valve4.3 ~ 4.8
Notice:If measured value is not within the specified value, check the pedal valve sensor and the supply voltage to
APP 1 sensor.
Acceleration Pedal Position Sensor 2 Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the signal voltage between the ECM pin No. 48 and No. 50 while operating the accelerator pedal as follow-
ing conditions.
DNot depress the pedal (closed throttle position)
DFully depress the pedal (full throttle with kick down)
Condition of Throttle Valve
Specified Value (V)
Closed Throttle Valve0.1 ~ 0.4
Fully Depressed Throttle Valve2.1 ~ 2.5
Notice:If measured value is not within the specified value, check the pedal valve sensor and the supply voltage to
APP sensor 2.
Page 490 of 2053
1F2 -- 72 M161 ENGINE CONTROLS
D AEW OO M Y_2000
COOLING FAN
KAB1F290
Failure
CodeDescriptionTrouble AreaMaintenance Hint
44Cooling fan (HI) relay
short circuit to powerCooling fan short circuit to
powerDInspection the Engine Control Module
(ECM) pin 35 about short circuit or
openwithbadcontact
45
Cooling fan (HI) relay
short circuit to ground or
openCooling fan short circuit to
ground or open
openwithbadcontact
DInspection the power source
DInspection the cooling fan
DInspection the ECM
Circuit Description
Ignition voltage is supplied directly to the cooling fan relay coil. The ECM controls the relay by grounding the control
circuit. When the ECM is commanding a command ON, the voltage of the control circuit should be low (near 0 volt).
When the ECM is commanding the control circuit should be high (near battery voltage). If the fault detection circuit
senses a voltage other than what is expected, the fault line status will change causing the fault code to set.
Page 493 of 2053
M161 ENGINE CONTROLS 1F2 -- 75
D AEW OO M Y_2000
TRACTION CONTROLSYSTEM (TCS)
KAB1F310
Failure
CodeDescriptionTrouble AreaMaintenance Hint
150TCS input signal short
circuit to batteryTCS short circuit to powerDInspection the Engine Control Module
(ECM) pin 45 about short circuit or
openwithbadcontact
151TCS input signal short
circuit to ground or openTCS short circuit to ground or
open
openwithbadcontact
DInspection the TCS lamp of I/P cluster.
DInspection the ECM
Circuit Description
Battery voltage is supplied to the TCS warning lamp with the ignition in ON and START. The warning lamp can be
activated only by the Electrical Brake Control Module (EBCM) internally supplying ground to terminal 32. If the TCS
input circuit is open or short, this failure codewill be set.
Page 494 of 2053
1F2 -- 76 M161 ENGINE CONTROLS
D AEW OO M Y_2000
STOP LAMP SWITCH
KAB1F320
Failure
CodeDescriptionTrouble AreaMaintenance Hint
135Stop lamp switch failure
When malfunction of stop
lamp switch – implausible
condition of stop lamp signal
input
DMonitoring the actual operational
status and vehicle speed signal
through scan tool
DInspection the Engine Control Module
(ECM) pin 49 about short circuit or
open with bad contact
DInspection the contact condition of
stop lamp switch
DInspection the ECM
Circuit Description
The stop lamp switch is normally opened. When the ignition switch ON and brake ON, the battery voltage is supplied to
the ECM. A scan tool should display ON when brake pedal is depressed and should read OFF with brake pedal rele-
ased.
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1F2 -- 84 M161 ENGINE CONTROLS
D AEW OO M Y_2000
Oxygen Sensor Signal Voltage Inspection
1. Maintain the engine speed is at idle while the coolant temperature is over 80°C.
2. Measure the oxygen sensor signal voltage between the ECM terminal No. 16 and No. 17.
Specified Value
-- 0.2 ~ 1.0 v
Notice:If the measured value is not within the specified value, the possible cause may be in cable, oxygen sensor or
ECM
Oxygen Sensor Heating Voltage Inspection
1. Maintain the engine speed is at idle while the coolant temperature is over 80°C.
2. Measure the oxygen sensor signal voltage between the ECM terminal No. 11 and No. 9.
Specified Value
11 ~ 14 v
Notice:If the measured value is not within the specified value, the possible cause may be in cable, oxygen sensor or
ECM
Oxygen sensor Heating Current Consumption Inspection
1. Turn the ignition switch to “ON” position.
2. Measure the oxygen sensor heating current consumption between the ECM terminal No. 9 and No. 5.
Specified Value
0.2~2.0A
Notice:If the measured value is not within the specified value, the possible cause may be in cable, oxygen sensor or
ECM