Remote start GMC Sierra 2500/3500 HD with key fob or mobile device

GMC Sierra 2500/3500 Heavy Duty supports remote start feature that allows you to remotely start the engine of your vehicle for the purpose of cooling or preheating the interior before the passengers gets to it.

2021 GMC Sierra 2500 HD Denali – (photo by GMC)

The remote start feature on GMC Sierra HD has many benefits. You can start your vehicle in advance when the weather is too hot or cold outside. The system turns on the air conditioning or heating, making inside cabin temperature more tolerable when you get to your vehicle.


Before you start your Sierra HD remotely, ensure that the vehicle is parked in a well ventilated area. Starting your vehicle in an enclosed space, like a closed garage, introduces risk of carbon monoxide poisoning.

Remote start procedure for Sierra HD

You can remotely start your GMC Sierra HD by following these simple steps:

  1. Press the LOCK button on the key fob of your Sierra HD.
  2. Then press and hold the REMOTE START button for about three seconds on the key fob.
  3. The turn signal lights flash and the engine starts.
  4. Once started remotely, the engine will run for 15 minutes and then shut down automatically.

The vehicle remains secured when you have remotely started the engine. A valid key must be inside your vehicle to switch the ignition on and drive your vehicle. The parking lamps will remain on as long as the engine is running.

Remotely stop Sierra HD’s engine

Press and hold the REMOTE START button on the key fob for three seconds to remotely stop the engine of your GMC Sierra HD. The parking lights turn off and the doors remain locked.

Extend engine running time

When you remotely start the engine of your GMC Sierra HD, it will run for 15 minutes and then shut off automatically. You can perform another remote start procedure by pressing the LOCK button and then holding the REMOTE START button for four seconds on the key fob, which will run the engine for another 15 minutes.

Maximum 30 minutes runtime

The engine run time can also be extended by another 15 minutes, if during the first 15 minutes remote start procedure is repeated while the engine is still running. An extension can be requested 30 seconds after starting. This provides a total of 30 minutes.


The remote start can only be extended once. When the remote start is extended, the second 15-minute period is added on to the first 15 minutes for a total of 30 minutes.

Maximum two remote starts

A maximum of two remote starts, or a remote start with an extension, are allowed between ignition cycles on Sierra HD. The vehicle must be started normally before the remote start procedure can be used again.

Climate control

The climate control system on GMC Sierra Heavy Duty will come on when the vehicle is started remotely, depending on the outside temperature. The rear defog and heated and ventilated seats, if equipped, may also come on when enabled.

Heated and Ventilated Seats

During a remote start, the heated or ventilated seats, if equipped, can be turned on automatically on your Sierra HD. When it is cold outside, the heated seats turn on, and when it is hot outside the ventilated seats turn on. If the auto heated or ventilated seats feature, if equipped, is not turned on, the heated or ventilated seats may be canceled when the ignition is turned on. If necessary, press the heated or ventilated seat button to use the heated or ventilated seats after the vehicle is started.

The heated or ventilated seats will not turn on during a remote start unless they are enabled in the vehicle personalization menu.

Enable or disable heated seats

If equipped and turned on, this feature will turn on the heated seats in your Sierra HD when using remote start on cold days.

  1. Press the Settings icon on the Home Page of the infotainment display.
  2. Press Vehicle to display a list of available options.
  3. Press Remote Lock, Unlock, and Start.
  4. Press Remote Start Auto Heat Seats.
  5. Turn the feature Off or On.
Remote start settings location in GMC infotainment system.

Automatic Heated Steering Wheel

The heated steering wheel on your GMC Sierra HD may turn on during a remote start when “Remote Start Auto Heat Seats” is enabled in the vehicle settings.

Enable or disable ventilated seats

If equipped and turned on, this feature will turn on the ventilated seats on your Sierra HD when using remote start on warm days.


  1. Press the Settings icon on the Home Page of the infotainment display.
  2. Press Vehicle to display a list of available options.
  3. Press Remote Lock, Unlock, and Start.
  4. Press Remote Start Auto Cool Seats.
  5. Turn the feature Off or On.

Steering column lock during remote start

It is normal for Sierra HD’s steering column to be locked during a remote start, but the column should unlock after the brake pedal is pressed and the vehicle is started.

Automatic engine shutdown after remote start

For safety and security reasons, the remote engine start system on GMC Sierra HD will prevent starting or stop the engine if running when one or more of the following conditions are met:

  • The total run-time has exceeded 30 minutes.
  • The coolant temperature gets too high.
  • The oil pressure gets low.
  • The security alarm is triggered.

In addition to the items above, if the vehicle’s engine management system determines there is a safety risk due to a vehicle-related problem, the vehicle will power down.

Remote start system not working on GMC Sierra HD

If the engine on your Sierra HD does not start when you perform the remote starting procedure, it can be due to a number of reasons:

  • The hood on your Sierra HD is not fully closed.
  • One or more of the vehicle doors are open, make sure they are securely closed.
  • The transmission is not in park mode (P).
  • The 12v battery voltage has gone too low.
  • The service engine light is turned on in the instrument cluster.
  • The remote key is in the vehicle.
  • There is an emission control system malfunction and the malfunction indicator lamp is on in your Sierra HD.
  • The hazard flashers are on.
  • Two remote vehicle starts or a start with an extension have already been used.
  • The remote start system on your Sierra HD has malfunctioned.

Your GMC Sierra HD may not have the remote start feature. Get your vehicle checked by an authorized dealer to confirm if it is equipped with a remote start system. If the vehicle does not have the remote start system, it may have the remote start ready feature. This feature allows your dealer to add the manufacturer’s remote vehicle start system.

Video Demonstration (key fob)

Watch this video to see how to remote start GMC 3500 Heavy Duty with key fob.

Remote start GMC Sierra HD with a mobile device

To remotely start the engine of your Sierra HD with an Apple or Android mobile device, you must at minimum subscribe to GM’s OnStar Remote Access Plan, which costs about $15 per month.

  1. Download “myGMC” app from App Store or Google Play on your mobile device.
  2. Tap the myGMC app icon on your device to start using the app.
  3. Next, select your region and country and tap Continue.
  4. Now sign-in to your GMC Owner Center account. If you don’t have an account, then create a new one.
  5. Accept User Terms and Privacy Statement prompts.
  6. Add your Sierra HD in myGMC app by entering your vehicle’s VIN number.
  7. Now press and hold the POWER button on the home screen.
  8. The turn signal lights flash and the engine starts.
  9. The engine will run for 15 minutes and then shut down automatically. A countdown is displayed on the power button.

Stop engine with mobile device

To remotely turn off your Sierra HD’s engine, touch the power button again that is displaying the engine shutdown countdown in myGMC app, then touch Turn Vehicle Off.

Video Demonstration (mobile device)

This video shows how to set up myChevrolet app, which has the same layout as myGMC app, since both are GM brands.

Watch this video to see how to set up myGMC app and remote start the vehicle.

Safety precautions

These are warnings against actions which may cause injury to people/vehicle if the warning is ignored.

  • Never start the engine of your Sierra HD in an enclosed area (such as a garage or indoor parking lot) where exhaust gases may accumulate and create a hazardous environment with potential for Carbon Monoxide (CO) poisoning.
  • Do not start the engine if a child or pet are present in or near the vehicle.
  • Always turn off vehicle systems such as the windshield wipers, headlights and radio before leaving the vehicle. If left on, such systems may be damaged or vehicle battery depleted by remote engine start in extreme cold weather.
  • Do not use remote start if the vehicle is low on fuel. The vehicle may run out of fuel.

Engine idling law

There are laws against car idling with no passenger or driver inside in many states to protect the environment. It does not mean its completely illegal to use remote start, some states have time limit on how long you can keep the engine running. So check with your local state laws before using the remote start feature on your GMC Sierra HD.

Author: Nabeel K
Email: nabeel@wheelsjoint.com