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How to Replace the Coolant Temperature Sensor on a 2015 Chevy Tahoe (5.3L)

  • Writer: Terry Clayton
    Terry Clayton
  • 6 hours ago
  • 3 min read

If your radiator fan is running constantly, your temperature gauge is acting strange, or you’ve got a check engine light related to engine temperature, your coolant temperature sensor may be the culprit.


In this guide, I’ll walk you step-by-step through how to replace the coolant temperature sensor on a 2015 Chevy Tahoe 5.3L. This is a straightforward DIY repair that can save you a few hundred dollars.


You can see a video on the repair here:


Symptoms of a Bad Coolant Temperature Sensor


You may notice:

  • Radiator fan running constantly

  • Check engine light

  • Inaccurate temperature gauge readings

  • Poor fuel economy

  • Hard starting when warm

In my case, the cooling fan was running when it shouldn’t, and replacing the sensor fixed the issue immediately.


Tools You’ll Need


  • 19mm deep socket

  • Extension

  • Ratchet (or small impact wrench if needed)

  • Small flathead screwdriver or pick tool

  • Shop rag

  • Optional: torque wrench


Step 1: Disconnect the Electrical Connector


The hardest part of this job is removing the connector — not the sensor itself.


Remove the White/Gray Safety Clip


There’s a small white (sometimes gray) locking tab that prevents the connector from being pressed.

  1. Insert a small screwdriver into the groove.

  2. Gently release the small lip.

  3. Slide the locking clip out.

  4. Set it aside — don’t lose it.


Take your time here. These clips can break if forced.


Release the Black Tab


Once the safety clip is removed:

  1. Press down on the black tab.

  2. Pull upward.

  3. The connector will come off the sensor.


Look inside the connector; you’ll see the black retaining tab that holds tension on the sensor. That’s what you’re releasing.


Step 2: Remove the Old Coolant Temperature Sensor


Now that the connector is off:

  1. Use a 19mm deep socket with extension.

  2. Break it loose.

  3. Unscrew it completely.

You can use a ratchet or carefully use an impact if needed.

The sensor should come out cleanly.


Step 3: Compare the Old and New Sensor


Before installing:

  • Compare thread size

  • Compare length

  • Compare connector style

They should look essentially identical.


Step 4: Install the New Sensor


  1. Thread it in by hand first to avoid cross-threading.

  2. Once seated, snug it down with a wrench.

  3. Do not overtighten — it threads into aluminum.

If using a torque wrench, follow manufacturer torque specs.


Step 5: Reconnect the Electrical Connector


  1. Push the connector back onto the sensor.

  2. Slide the white/gray safety clip back into place.

  3. Make sure it clicks and locks.


Step 6: Start the Engine and Verify Repair


Start the vehicle and check:

  • Is the radiator fan running constantly? (It shouldn’t be.)

  • Is the temperature gauge behaving normally?

  • Any warning lights?

In my case:

  • Fan no longer ran continuously

  • No leaks

  • Problem fixed


Final Step: Check for Leaks


After installation:

  • Inspect around the sensor threads.

  • Make sure there’s no coolant seeping.

  • Recheck after a short drive.

If it’s dry — you’re done.


Estimated Time & Difficulty


  • Time: 20–30 minutes

  • Difficulty: Easy

  • Estimated shop cost avoided: $200–$400


Why This Fix Works


The coolant temperature sensor tells the ECU how hot the engine is. If it fails:

  • The computer may default to a protective mode

  • The cooling fan may run constantly

  • Fuel mixture may run rich


Replacing it restores proper temperature readings and normal cooling system behavior.

If this repair saved you time or money, consider subscribing to the channel and checking out more DIY repair guides.

 
 
 

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