2018 silverado 1500 5.3 engine fans come on at high speed and won't shut off until I disconnect the battery

[Leroy Jordan]

My 2018 silverado has a problem,  for no apparent reason at times the engine FANS come on at high speed and won't shut off until I disconnect the battery post., I've already replaced the temperature control sensor and the problem ceased for about a month., I guess now replace the thermostat.,

 I thought that this problem was gone but only to return a month later. 

  Any thoughts on this issue?

[GMCustomerService]

This isn't the experience we'd like for you to continue to have with your Silverado. At this time, we'd like to connect further so we can learn more and assist in brining this matter towards the resolution you need. To do so, please email us at [email protected] with your Username and Forum in the subject line with additional details. We look forward to your outreach. 

[MikeBMW]

On 2/15/2026 at 8:30 PM, Leroy Jordan said:

My 2018 silverado has a problem,  for no apparent reason at times the engine FANS come on at high speed and won't shut off until I disconnect the battery post., I've already replaced the temperature control sensor and the problem ceased for about a month., I guess now replace the thermostat.,

 I thought that this problem was gone but only to return a month later. 

  Any thoughts on this issue?

When I start my truck on a warm day, the FANS turn on at high speed - I'm guessing you're meaning the radiator FANS?
After a bit of driving, they turn off until they're needed.
Generally, the FANS are there to cool the radiator until the coolant flow gets going.
Just give the FANS a bit of time and let the ECM or BCM learn the process.
Disconnecting the battery just resets the learning process.

Edited March 6 by MikeBMW