Replace the engine coolant temperature sensor on a 2018-2024 Toyota Camry 2.5L I4 engine to restore accurate temperature readings to the ECU and instrument cluster.

Warnings

Tools required

Parts

• Engine coolant temperature sensor × 1 — Toyota 90919-05060 or equivalent
• Coolant drain plug gasket × 1 — Use OEM specification

Fluids

• Toyota Super Long Life Coolant (Pink) — 2 qt

Preparation

1. Ensure the engine is completely cold (not run for at least 2 hours)
2. Park vehicle on level ground and engage parking brake
3. Remove the engine cover by pulling upward on the front edge, then lifting
4. Place drain pan under radiator drain plug located at bottom driver's side of radiator

Procedure

1. 1

   Drain coolant partially
   Open the radiator drain plug at the bottom of the radiator on the driver's side. Drain approximately 1-2 quarts of coolant into the drain pan until the coolant level is below the sensor location. The sensor is positioned on the engine block near the thermostat housing. Close the drain plug with a new gasket once sufficient coolant has drained.
   Torque spec

   Coolant Drain Plug15 Nm (11 lb-ft)
2. 2

   Locate coolant temperature sensor
   The engine coolant temperature sensor is located on the driver's side of the engine block, below the throttle body and near the thermostat housing. It has a single electrical connector and is threaded directly into the engine block. Verify you have located the correct sensor before proceeding.
   ℹ️Do not confuse the coolant temperature sensor with the coolant temperature switch for the gauge, which may be located nearby.
3. 3

   Disconnect electrical connector
   Press the locking tab on the sensor's electrical connector and carefully pull the connector straight off the sensor. You may need to use needle nose pliers to depress the tab if it is difficult to access. Set the connector aside where it will not contact coolant.
   ⚠Do not pull on the wiring harness itself. Only pull on the connector body to avoid damaging the wires.
4. 4

   Remove coolant temperature sensor
   Using a 19mm deep socket or wrench, carefully unscrew the coolant temperature sensor counterclockwise. Have a shop towel ready to catch any residual coolant that drains from the sensor port. Remove the sensor completely and inspect the sealing washer or O-ring on the old sensor.
   ⚠Coolant will drain from the sensor port once removed. Work quickly to minimize coolant loss.
5. 5

   Prepare new sensor
   Remove the new coolant temperature sensor from its packaging. Verify that it has a new sealing washer or O-ring installed. Do not reuse the old washer. Clean the sensor mounting hole in the engine block with a shop towel to remove any debris or old sealant.
6. 6

   Install new sensor
   Thread the new coolant temperature sensor into the engine block by hand, turning clockwise. Ensure it threads smoothly without cross-threading. Once hand-tight, use the 19mm socket or wrench to tighten the sensor snugly. Torque to 15-20 Nm (11-15 lb-ft) or snug with a wrench - do not overtighten as this can crack the sensor body or damage the threads.
   ⚠The sensor threads into aluminum. Cross-threading or overtightening can strip the threads in the engine block, requiring expensive repairs.
7. 7

   Reconnect electrical connector
   Push the electrical connector firmly onto the new sensor until you hear or feel it click into place. Tug gently on the connector to verify it is securely locked. Ensure no coolant has contaminated the connector pins.
8. 8

   Refill coolant system
   Using a funnel, slowly pour Toyota Super Long Life Coolant (Pink) into the radiator and coolant reservoir to restore the system to the proper level. Fill the radiator to the base of the filler neck and the reservoir to the FULL line. Add coolant slowly to prevent air pockets from forming.
   ℹ️Use only Toyota Super Long Life Coolant (Pink). Mixing coolant types can cause corrosion and cooling system damage.
9. 9

   Bleed cooling system
   With the radiator cap still off, start the engine and allow it to idle. Monitor the coolant level and add more as needed as the system purges air. Run the engine until the cooling fan cycles on, indicating the thermostat has opened. Squeeze the upper radiator hose several times to help release trapped air. Top off coolant as necessary.
   ⚠Keep hands away from the cooling fan and drive belts while the engine is running.
10. 10

    Final inspection and pressure test
    Turn off the engine and allow it to cool for 10 minutes. Check the coolant level again and top off if needed. Inspect the area around the new sensor for any signs of coolant leaks. Install the radiator cap and reinstall the engine cover. Start the engine and verify the temperature gauge operates normally.

Reassembly

1. Ensure all electrical connectors are fully seated and locked
2. Verify radiator cap is properly installed and tightened
3. Reinstall engine cover by aligning clips and pressing down until secure
4. Double-check coolant level in reservoir when engine is cold

Verification

• Start the engine and verify the temperature gauge rises to normal operating temperature within 5-10 minutes
• Check for coolant leaks around the sensor with the engine at operating temperature
• Use an OBD-II scanner to verify no coolant temperature sensor codes are present (P0115, P0116, P0117, P0118)
• Verify the engine cooling fan cycles on when the engine reaches operating temperature
• Recheck coolant level after the first drive cycle and top off if necessary

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