Block Heater Cord Temp. Sensor

Salsa De Piña · November 18, 2019

I just recently picked up a new '19 Legacy, and was checking out the block heater cord as it's that time of year. It appears to have a normal plug, without the temperature sensor. Has GM gone away from these, or is the temperature sensor somewhere else? The manual says the thermostat may exist in the plug end, but I figure that's because the Duramax probably doesn't have one.

dieselfan1 · November 18, 2019

I believe the thermostat is built in. Unless you live way North I don't think you need to plug in.

Does anyone South of the Canadian border even plug in a gasser? I don't.

Salsa De Piña · November 18, 2019

I'm in Winnipeg, and the truck sits outside and isn't daily driven. A block heater is something I care about.

I had an '07 Canyon, so I'm very familiar with what the thermostat plug looks like. The new truck doesn't have it. The Canyon didn't like starting when it got cold.

dieselfan1 · November 18, 2019

Put it on a timer then.

damnthetorpedoes · November 18, 2019

I would much prefer that mine didn't have the thermostat on the cord. There are benefits to block heaters before the temp drops below 0F. My 17 has the thermostat on the cord/plug that you are talking about, so I will be interested to hear if others have a cords without.

Salsa De Piña · November 18, 2019

Putting a timer on it won't help warm the truck up faster when it's -15. It also didn't help my Canyon start when it was -15. But I digress...

I picked up a block heater tester on the way home today and it was showing negative when I plugged the truck in at 0 degrees Celsius. Then I noticed the little module part way down the block heater cord, attached to the inner fender. Maybe they just relocated the sensor because plugs tend to get damaged and replaced.

CamGTP · November 19, 2019

10 hours ago, dieselfan1 said:

I believe the thermostat is built in. Unless you live way North I don't think you need to plug in.

Does anyone South of the Canadian border even plug in a gasser? I don't.

I do and we live in the same city. I park outside so I like to use one.

I modded my two previous cords with the thermostat in them. Basically broke them and soldered a wire across the contacts to make it work all the time. My 16 didn't come with one so I bought a oil pan heater instead, it's all ready to go for when it's really cold.

Gmman · November 19, 2019

I put a block heater on my 2017 6.0. When I bought it, I got the one with out the thermostat in the cord.

Mozzer · November 23, 2019

For those who have taken out the thermostat in the cord, do you get codes thrown & if so does it affect the running or emissions?

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CamGTP · November 23, 2019

I never got any codes. I didn't have it run 24/7 either, had the code on a timer that would vary the on time. I think I started it around 3-4am so it would run for like 30min on, then off for a bit. Doing that always got the coolant temps up 30-40º F above ambient.

Mozzer · November 23, 2019

I never got any codes. I didn't have it run 24/7 either, had the code on a timer that would vary the on time. I think I started it around 3-4am so it would run for like 30min on, then off for a bit. Doing that always got the coolant temps up 30-40º F above ambient.

Great, I will be getting rid of it too then. If I know what time I'm leaving in the morning I usually put a timer on for an hour two before that depending on how cold it is.

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Gmman · November 24, 2019

I had mine on a timer as well. I had it come on at 1am and go off at 5am. No codes.

dieselfan1 · November 25, 2019

On 11/18/2019 at 5:39 PM, Salsa De Piña said:

Putting a timer on it won't help warm the truck up faster when it's -15. It also didn't help my Canyon start when it was -15. But I digress...

I picked up a block heater tester on the way home today and it was showing negative when I plugged the truck in at 0 degrees Celsius. Then I noticed the little module part way down the block heater cord, attached to the inner fender. Maybe they just relocated the sensor because plugs tend to get damaged and replaced.

13 hours ago, Gmman said:

I had mine on a timer as well. I had it come on at 1am and go off at 5am. No codes.

On 11/18/2019 at 1:27 PM, dieselfan1 said:

Put it on a timer then.

Like I said put a timer on it.

L86 All Terrain · November 25, 2019

On 11/18/2019 at 12:24 PM, dieselfan1 said:

I believe the thermostat is built in. Unless you live way North I don't think you need to plug in.

Does anyone South of the Canadian border even plug in a gasser? I don't.

I'm in northern Ontario. I rarely plug in my gas trucks. Not until its -28c or colder. The reason being is if you plug your truck in at -15c or w/e temp the plug cuts in every night, the truck will become accustomed to starting warm and the one day you need to do a -30c cold start your going to kill your battery and be mad in the cold. We work in the bush so it is not really an option to have a gas truck that wont start without being plugged in. We run Espar's or Webasto's auxillery block heaters on all the diesels, which all have plug in block heaters and some have oil pan heaters also. Now I just wish they could invent something to prevent frozen brakes and I'd be laughing.