ECT sensor - 1999 Kia Sportage

code p 0442 refers to EVAP system so that is unlikely
check the fan operation and if you have a viscous fan hub ( fan clutch ) replace it
if you have electric fans , check coolant temperature sensor for operation , fuses , relay and fans
overheating is from low coolant levels , head gaskets/cracked heads, blocked radiator cores , fins flaking off core tubes, incorrect timing, blocked exhaust( cat converter)problem thermostat, over loading /over speeding, overdrive not engaging
if you over heating is predominately at lights , slow moving traffic or high engine rpms with low speed --check the fan operation and if it is viscous fan hub driven --replace the hub or if electric fans have that circuit checked out

The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The ECT sensor has a signal circuit and a low reference circuit. The engine control module (ECM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the ECM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the ECM detects a lower voltage on the ECT signal circuit. If the ECM detects an excessively high ECT signal voltage, which is a low temperature indication, DTC P0118 sets. You have A bad coolant temp sensor or a wiring problem !

Try looking screwed into the radiator.

Automobiles: 2000 Ford Escort ZX2 4-cylinder 2.0L MFI DOHC

NOTE
The "left" side of the engine is the driver's side.

The Engine Coolant Temperature (ECT) sensor is a thermistor (a device which changes resistance or voltage as temperature changes). The sensor detects the temperature of engine coolant and provides a corresponding signal to the PCM (Powertrain Control Module - aka "the car's computer").

The ECT sensor is mounted in the following locations (small Ford engines):

1.8L engines: in the cylinder head
1.9L engines: threaded into the heater hose inlet pipe
2.0L engines: at the left rear of the engine

2.0L Zetec Engine

(1) Partially drain the engine cooling system using a clean container. If coolant is in good condition, retain for reuse.
(2) Disconnect the battery ground cable.
(3) Disconnect the electrical wiring connector from the engine coolant temperature (ECT) sensor.
(4) Remove the retaining clip and the ECT sensor.




Fig. 1 Escort ZX2 ECT sensor - The retaining clip is removed (at the solid arrow). Withdraw ECT sensor by gently wiggling/pulling in the direction of the dashed arrow.

To install:

NOTE
Coat the ECT sensor O-ring with clean coolant prior to installation.

(1) Replace the retaining clip and the ECT sensor.
(2) Connect the electrical wiring connector from the Engine Coolant Temperature (ECT) sensor.
(3) Connect the battery ground cable.
(4) Refill the engine cooling system. An inexpensive plastic "Radiator Funnel" will help with this task.

P0117 - Engine Coolant Temperature (ECT) Circuit Low Input

The ECT (Engine coolant temperature) sensor is a thermistor located in the engine block or other coolant passage. It changes resistance with changes in temperature of the coolant that it's in contact with. It's usually a two wire sensor. One wire is a 5 volt reference from PCM (Powertrain Control Module) and the other is a ground supplied from PCM.

As the temperature of the coolant changes, the resistance of the sensor changes. When the engine is cold, the resistance is high. When the engine is warm, the resistance is low. If the PCM detects a signal voltage lower than the normal operating range of the sensor then P0117 code will set.

Potential symptoms include:
* MIL (Malfunction Indicator Lamp) illumination
* Poor fuel economy
* Poor drivability
* Engine may run rough or blow black smoke out the tailpipe
* May not idle
* May start and then die

Causes: Potential causes of the P0117 code include:
* Bad ECT sensor
* Short to ground on ECT signal circuit
* Faulty or damaged connectors
* Wiring harness damaged
* Loose terminals at ECT or PCM
* POSSIBLY an overheated engine
* Bad PCM

Possible Solutions: Since this code is for an abnormally low signal to the PCM from the ECT, the PCM saw a excessively "hot" condition in the engine coolant. This could be due to faulty ECT sensor or wiring, but it could, conceivably, be caused by an overheated engine.So if your engine was overheated diagnose that first. Having said that here are the possible solutions:

Using a scan tool, with KOEO (Key on engine off) check the ECT reading on the display. On a cold engine the ECT reading should match the IAT (Intake Air Temperature) sensor reading. If it doesn't, replace the ECT sensor.

1. If the ECT reading is showing an excessively hot reading, for example more than 260 deg. F, then unplug the ECT sensor. This should cause the ECT reading to drop to the extreme cold reading (around -30 deg.F or so). If it does, replace the sensor, because it's internally shorted. If it doesn't change the reading, the check for a short to ground on the signal circuit of the ECT wiring. It could be that the two ECT wires are shorted to each other. Look for any chafing or melted wiring. Repair as necessary.
a. If you can't find any wiring problems and the ECT reading doesn't drop to the extreme coldest when unplugged, then, check for voltage coming out of the PCM on the signal wire's pin at the PCM connector. If there isn't any voltage, or it is low, then the PCM may be bad. NOTE: On some models it is possible for the 5 Volt reference signal to be temperarily shorted. This can happen if an engine sensor internally shorts the 5 Volt reference. Since the 5 Volt reference is a "shared" circuit on many models, this will cause it to be abnormally low. Usually, though this will be accompanied by several other sensor codes. If you suspect that may be the case, unplug each sensor until the 5 Volt reference reappears. The last sensor unplugged is the offending sensor. Replace and recheck the signal wire from the PCM connector

2. If the scan tool ECT reading seems normal at this time then the problem may be intermittent. Use a "wiggle" test to manipulate the wiring harness and connectors while watching the ECT reading on the scan tool. Repair any wiring or connectors that are loose or corroded. You could check the Freeze frame data if your scan tool has that function. It will show the ECT reading when the failure occurred. If it shows the reading to be at the hottest extreme then replace the ECT sensor and see if the code reappears.

Other ECT sensor and circuit related DTCs: P0115, P0116, P0118, P0119, P0125, P0128

Hope this help to check and solve it.

Coolant Temperature Sensor I would take the vehicle back to where it was serviced and try to ask them about what may have gone wrong to cause this problem.
The Intake Air Temperature sensor should also be checked.

The following is the procedure for servicing the coolant temperature sensor: Removal & Installation 3.8L Engine To Remove:

1. Drain the coolant.
2. Disconnect the engine coolant temperature (ECT) sensor connector. ECT sensor 3.8L
   
   
3. Remove the ECT sensor.

To Install:

1. Apply thread sealer P/N 12346004 or equivalent to the engine coolant temperature (ECT) sensor threads.
2. Install the ECT sensor. Tighten 18 ft-lb (25 Nm).
3. Connect the ECT sensor harness connector.
4. Fill the cooling system.

5.3L Engine To Remove:

1. Drain the coolant below the level of the engine coolant temperature (ECT) sensor.
2. Disconnect the ECT sensor electrical connector. ECT sensor 5.3L
   
   
3. Remove the ECT sensor from the cylinder head.

To Install:

1. Clean the threads in the sensor mounting hole.
2. Apply sealer P/N 13246004 or equivalent to the threads of the sensor.
3. Install the sensor and tighten 15 ft-lb (20 Nm).
4. Connect the ECT sensor electrical connector.
5. Fill the cooling system and check for leaks.

Removal & Installation To Remove:
ECT sensor 3.5L engine

1. Disconnect the battery ground cable.
2. Drain the coolant below the level of the engine coolant temperature (ECT) sensor.
3. Disconnect the ECT sensor electrical connector.
4. Carefully remove the ECT sensor.

To Install:
WARNING
Damage to the coolant sensor will affect the operation of the fuel control system.

1. Coat the ECT sensor threads with thread sealer.
2. Install the ECT sensor. Tighten the sensor to 15 ft lb (20 Nm) on 3.5L engines and 22 ft lb (30 Nm) on 3.8L engines.
3. Install the ECT sensor electrical connector.
4. Connect the battery ground cable.
5. Refill the cooling system using the recommended procedure.

4.2L Engine To Remove:

1. Disconnect the negative battery cable from the battery.
2. Drain the coolant from the engine.
3. Disconnect the engine coolant temperature (ECT) sensor connector. Engine coolant temperature sensor removal and installation
   
   
4. Remove the engine coolant temperature (ECT) sensor from the engine.

To Install:

1. Apply thread sealer P/N 12346004 or equivalent to the engine coolant temperature (ECT) sensor threads.
2. Install the engine coolant temperature (ECT) sensor into the engine. Torque the sensor to 12 ft-lb (16 Nm).
3. Connect the engine coolant temperature (ECT) sensor connector.
4. Refill the engine with coolant.
5. Connect the negative battery cable to the battery.

5.3L & 6.0L Engines To Remove:

1. Drain the coolant from the engine.
2. Disconnect the engine coolant temperature (ECT) sensor connector. Engine coolant temperature sensor removal and installation
   
   
3. Remove the engine coolant temperature (ECT) sensor from the left cylinder head.

To Install:

1. Apply thread sealer P/N 12346004 or equivalent to the engine coolant temperature (ECT) sensor threads.
2. Install the engine coolant temperature (ECT) sensor into the left cylinder head. Torque the sensor to 15 ft-lb (20 Nm).
3. Connect the engine coolant temperature (ECT) sensor connector.
4. Refill the engine with coolant.

please rate as fixya if this helps

SECTION 303-14: Electronic Engine Controls 2000 F-150 Workshop Manual
REMOVAL AND INSTALLATION Engine Coolant Temperature (ECT) Sensor — 4.6L and 5.4L Removal and Installation

1. Remove the engine coolant temperature (ECT) sensor.
   1. Disconnect the electrical connector.
   1. Remove the ECT sensor.

The ECT sensor:

• sends the PCM a signal indicating engine temperature.
• resistance decreases as coolant temperature increases.

The ECT measures the temperature of the engine coolant. The sensor is threaded into an engine coolant passage.

The code means a Engine Coolant Temperature Sensor Circuit Malfunction. Some of the possible causes.

ECT sensor signal circuit is open or shorted ground
ECT sensor ground circuit is open between sensor and PCM
ECT sensor signal circuit is shorted to VREF or system power
ECT sensor is damaged or has failed
PCM has failed

Testing will need to be done to find out the cause.