Hyundai 39220-38030 Sensor & G/UNIT-Water TEMPERTURE

This checking procedure applies only to 2006 and earlier models, as 2007 and later models require special equipment and procedures. The Engine Coolant Temperature (ECT) sensor is located at the front left corner of the cylinder head on 2010 and earlier 1.8L and 2012 and earlier 2.0L models, while on 2011 and later 1.4L models and all 2013 and later models, it is found on the driver's side end of the cylinder head. Begin by draining the cooling system and, for 1.4L and 1.6L models, removing the air filter housing. Next, move the wiring harness and vacuum lines out of the way, then unplug the electrical connector from the ECT sensor by prying up the wire retainer and pulling the connector off. For all models except 1.4L, unscrew and remove the ECT sensor; for 1.4L models, remove the locking clip and pull the sensor out of the water temperature control housing. Suspend the ECT sensor in a container of water and heat the water while monitoring the temperature with a cooking thermometer, ensuring the sensor does not touch the sides or bottom of the container. Connect an ohmmeter to the sensor terminals and measure the resistance as the water heats, comparing the measurements with specified resistance values and replacing the sensor if there is a significant variation. Before installing the ECT sensor, ensure the brass sealing washer is in place if equipped, and for all models except 1.4L, tighten the sensor to the specified torque. For 1.4L models, lubricate the sensor with clean coolant before inserting it into the water temperature control housing until the locking clip can be installed. After installation, fill the cooling system, start the engine, and check for leaks, with installation being the reverse of removal.

On 1986 to 1989 models, the temperature gauge coolant sender is threaded into the bottom of the intake manifold, behind the distributor. For 1990 through 1994 models, the sending unit is threaded into the intake manifold near the thermostat cover. On 1990 to 1994 carbureted models, a thermo switch is located below the temperature sender on the intake manifold to actuate the purge control valve of the Evaporative Emissions System, the choke breaker, and the Exhaust Gas Recirculation (EGR) valve. On 1990 and later fuel-injected models, the temperature sensor and temperature sender are located near the thermostat. On 1995 through 1999 models, the lower sensor is the temperature sender unit for the temperature gauge, while the upper sensor is the Engine Coolant Sensor (ECT) used by the ECM. To check if the coolant temperature gauge is inoperative, verify the fuses first. If the temperature gauge indicates Hot shortly after cold engine start, disconnect the wire(s) at the coolant temperature sending unit. If the gauge reading drops, replace the sending unit. If the reading remains high, there might be a shorted wire to the gauge or a faulty gauge. Note that on 2000 and later models, the temperature sending unit function is integrated into the Engine Coolant Temperature (ECT) sensor, requiring a scan tool or code reader for diagnosis. If the coolant temperature gauge fails to indicate after engine warming, and fuses are fine, disconnect the green/yellow wire at the sending unit, connect it to a clean ground, turn on the ignition, and if the gauge shows Hot, replace the sending unit. If the gauge still doesn't work, there could be an open circuit or a faulty gauge. Further testing involves measuring sender resistance by unplugging the wiring and connecting an ohmmeter between the sender terminal and a ground point. The sender unit's resistance should match specifications for the coolant temperature. A sender reading open or short circuit will provide a constant full hot or full cold signal when the ignition switch is ON. For replacement, with the engine cool, release any pressure by removing and replacing the radiator cap, disconnect the wiring harness from the sending unit, apply sealer to the threads of the new sending unit, unscrew the old sending unit and quickly install the new one to prevent coolant loss, tighten securely, connect the wiring harness, refill the cooling system, run the engine, and check for leaks and proper temperature gauge operation on the instrument panel.

To avoid problems with the ECT sensor, one must avoid any physical contact with this part because any damage to it will result in a failure of the entire fuel injection system. The ECT sensor is Mounted at the driver end of the engine either in the thermostat housing or in the coolant passage as shown in fig 11. First, unplug the cable from the negative terminal and bleed the cooling system by draining a little amount of it. Then, remove the electrical connector of ECT sensor by pulling it off and then unscrew the sensor from the cylinder head. Do not screw tight the new ECT sensor's threads with teflon due to it; as this will affect the grounding you should apply little liquid sealer on the threads before screwing tightly. Last, installations; This is the opposite of the removal where it is made sure that the ECT sensor is well tightened and the cooling system is refilled.

Handle the ECT sensor with care, as damage will affect the operation of the entire fuel injection system. The ECT sensor is located at the driver's end of the engine near the thermostat housing for 2010 and earlier models. Begin by disconnecting the cable from the negative battery terminal and partially draining the cooling system. Next, disconnect the electrical connector from the ECT sensor, unscrew the sensor from the coolant passage, and avoid sealing the threads of the new sensor with Teflon tape, as this will interfere with grounding; instead, apply a small amount of liquid sealer to the threads before installation. Installation is the reverse of removal, ensuring the sensor is tightened securely, followed by refilling the cooling system. For 2011 and later models, the ECT sensor is located on the back side of the cylinder head. Remove the spring clip and pull the sensor from the coolant temperature control housing, then install the new sensor in reverse order, securing it with the spring clip and refilling the cooling system afterward.

If the gauge shows a high temperature after warming up, investigate the issue further.