How to keep radio on when truck is off

oldmann · October 31, 2019

21 hours ago, Shawn O'Leary said:

No, if you hold down the start button for several seconds without depressing the brake it puts it into a mode that basically everything functions as though the truck is on and running, without starting the engine. This is different than the ACC mode where the radio dies every 5 minutes. I used this when the oil cooler line failed on my 6.2L Sierra and had to wait over an hour for the tow truck. It also allows you to shift the truck into neutral without starting it, FYI.

Doesn't work on mine. I can hold it for 10 seconds and it doesn't matter.

Cpl_Punishment · October 31, 2019

6 hours ago, Tonarcher said:

Can a 2019 without push button start also be put in service mode ?

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Wouldn't that just be turning the key two clicks to the run position?

redwngr · October 31, 2019

6 hours ago, Tonarcher said:

Can a 2019 without push button start also be put in service mode ?

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Yes.

The On/ run position will do that.

Positions are:

0. Stopping the Engine/LOCK/OFF
1. ACC/ACCESSORY
2. ON/RUN
3. START

570590 already posted the section of the OM for push button start.

The owners manual says this for the key ignition trucks:

2 (ON/RUN) : This position can be used to operate the electrical accessories and to display some
instrument cluster warning and indicator lights. This position can also be used for service and
diagnostics, and to verify the proper operation of the malfunction indicator lamp as may be required
for emission inspection purposes.
The switch stays in this position when the engine is running. The transmission is also unlocked in this position.
If the key is left in ON/RUN with the engine off, the battery could drain and the vehicle may not start.

I know, I know, back in the day we were trained not to leave them in the ON position ....and that we should use ACC instead if we wanted to run the radio.