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Coolant Temperature Sensor/Switch (For Computer)

Engine, Cooling and Exhaust › Cooling System
Unified entry — merged from multiple cross-listed pages in the original manual.

Parts

PartCoolant Temp Sensor
ManufacturerCHY
OEM part #5149096AB
Price$6.10

Labor

Replace — Coolant Temp Sensor0.4 hr
Warranty 0.0 hrSkill B
Procedures
Engine Coolant Temperature Sensor - Installation4 steps
Fig. 1
Fig. 1
Fig. 2
Fig. 2
  1. Apply thread sealant to sensor threads.
  2. Install sensor to engine.
  3. Tighten coolant temperature sensor to 11 Nm (8 ft. lbs.) torque.
  4. Replace any lost engine coolant.
Engine Coolant Temperature Sensor - Removal3 steps
⚠ WARNING
Hot, pressurized coolant can cause injury by scalding. Cooling system must be partially drained before removing the coolant temperature sensor.
Fig. 1
Fig. 1
Fig. 2
Fig. 2
  1. Partially drain cooling system.
  2. Disconnect electrical connector from sensor.
  3. Remove sensor from intake manifold.
Engine Coolant Temperature Sensor - Operationreference
OPERATION At key-on, the Powertrain Control Module (PCM) sends out a regulated 5 volt signal to the ECT sensor. The PCM then monitors the signal as it passes through the ECT sensor to the sensor ground (sensor return). When the engine is cold, the PCM will operate in Open Loop cycle. It will demand slightly richer air-fuel mixtures and higher idle speeds. This is done until normal operating temperatures are reached. The PCM uses inputs from the ECT sensor for the following calculations: -for engine coolant temperature gauge operation through the bus communications -Injector pulse-width -Spark-advance curves -ASD relay shut-down times -Idle Air Control (IAC) motor key-on steps -Pulse-width prime-shot during cranking -O2 sensor closed loop times -Purge solenoid on/off times -EGR solenoid on/off times (if equipped) -Leak Detection Pump operation (if equipped) -Radiator fan relay on/off times (if equipped) -Target idle speed
Engine Coolant Temperature Sensor - Installation4 steps
Fig. 1
Fig. 1
Fig. 2
Fig. 2
  1. Apply thread sealant to sensor threads.
  2. Install sensor to engine.
  3. Tighten coolant temperature sensor to 11 Nm (8 ft. lbs.) torque.
  4. Replace any lost engine coolant.
Engine Coolant Temperature Sensor - Removal3 steps
⚠ WARNING
Hot, pressurized coolant can cause injury by scalding. Cooling system must be partially drained before removing the coolant temperature sensor.
Fig. 1
Fig. 1
Fig. 2
Fig. 2
  1. Partially drain cooling system.
  2. Disconnect electrical connector from sensor.
  3. Remove sensor from intake manifold.
Engine Coolant Temperature Sensor - Operationreference
OPERATION At key-on, the Powertrain Control Module (PCM) sends out a regulated 5 volt signal to the ECT sensor. The PCM then monitors the signal as it passes through the ECT sensor to the sensor ground (sensor return). When the engine is cold, the PCM will operate in Open Loop cycle. It will demand slightly richer air-fuel mixtures and higher idle speeds. This is done until normal operating temperatures are reached. The PCM uses inputs from the ECT sensor for the following calculations: -for engine coolant temperature gauge operation through the bus communications -Injector pulse-width -Spark-advance curves -ASD relay shut-down times -Idle Air Control (IAC) motor key-on steps -Pulse-width prime-shot during cranking -O2 sensor closed loop times -Purge solenoid on/off times -EGR solenoid on/off times (if equipped) -Leak Detection Pump operation (if equipped) -Radiator fan relay on/off times (if equipped) -Target idle speed
Factory service manual
From the 2008 KK factory manual — descriptions, specs, torque & procedures for this part.
SENSOR-ENGINE COOLANT TEMPERATURE

Description

The Engine Coolant Temperature (ECT) sensor is used to sense engine coolant temperature. The sensor protrudes into an engine water jacket.
The ECT sensor is a two-wire Negative Thermal Coefficient (NTC) sensor. Meaning, as engine coolant temperature increases, resistance (voltage) in the sensor decreases. As temperature decreases, resistance (voltage) in the sensor increases.

Operation

At key-on, the Powertrain Control Module (PCM) sends out a regulated 5 volt signal to the ECT sensor. The PCM then monitors the signal as it passes through the ECT sensor to the sensor ground (sensor return).
When the engine is cold, the PCM will operate in Open Loop cycle. It will demand slightly richer air-fuel mixtures and higher idle speeds. This is done until normal operating temperatures are reached.
The PCM uses inputs from the ECT sensor for the following calculations:
for engine coolant temperature gauge operation through the bus communications Injector pulse-width Spark-advance curves ASD relay shut-down times Idle Air Control (IAC) motor key-on steps Pulse-width prime-shot during cranking O2 sensor closed loop times Purge solenoid on/off times EGR solenoid on/off times (if equipped)
Leak Detection Pump operation (if equipped) Radiator fan relay on/off times (if equipped) Target idle speed
REMOVAL-2.8L DIESEL📷 1
1 - CYLINDER HEAD BOLT 2 - GLOW PLUG 3 - COOLANT FITTING 4 - CYLINDER HEAD ALIGNMENT DOWEL 5 - GLOW PLUG HARNESS 6 - CYLINDER LINER 7 - CYLINDER BLOCK 8 - CYLINDER HEAD GASKET 9 - CYLINDER HEAD 10 - ROCKER ARM ASSEMBLIES
WARNING: Do not remove or loosen the coolant pressure/vent cap, cylinder block drain plugs, or the draincock when the system is hot and under pressure because serious burns from the coolant can occur.
  1.   Disconnect negative battery cable.
  2.   Drain the cooling system. See STANDARD PROCEDURE.
  3.   Disconnect coolant temperature sensor electrical connector.
  4.   Remove coolant temperature sensor (3) from cylinder head.
figure
REMOVAL-3.7L ENGINE📷 1
1 - MOUNTING SCREWS 2 - MAP SENSOR 3 - ECT SENSOR 4 - FRONT OF INTAKE MANIFOLD
The Engine Coolant Temperature (ECT) sensor (3) is installed into a water jacket at front of intake manifold near rear of generator.
WARNING: Hot, pressurized coolant can cause injury by scalding. Cooling system must be partially drained before removing the coolant temperature sensor.
1. Partially drain cooling system. 2. Disconnect electrical connector from sensor. 3. Remove sensor from intake manifold.
figure
ENGINE COOLANT TEMPERATURE SENSOR-INSTALLATION-2.8L DIESEL ENGINE📷 1
1 - CYLINDER HEAD BOLT 2 - GLOW PLUG 3 - COOLANT FITTING 4 - CYLINDER HEAD ALIGNMENT DOWEL 5 - GLOW PLUG HARNESS 6 - CYLINDER LINER 7 - CYLINDER BLOCK 8 - CYLINDER HEAD GASKET 9 - CYLINDER HEAD 10 - ROCKER ARM ASSEMBLIES
  1.   Install coolant temperature sensor in thermostat housing.
  2.   Connect coolant temperature sensor electrical connector.
  3.   Refill cooling system. See STANDARD PROCEDURE.
  4.   Connect negative battery cable.
figure
INSTALLATION-3.7L ENGINE
1 - MOUNTING SCREWS 2 - MAP SENSOR 3 - ECT SENSOR 4 - FRONT OF INTAKE MANIFOLD
  1.   Apply thread sealant to sensor threads.
  2.   Install sensor to engine.
  3.   Tighten coolant temperature sensor to 11 N.m (8 ft. lbs.) torque.
  4.   Replace any lost engine coolant.