Bypassing Block Heater Sensor

[Forkster]

I notice than when its a little cold here (or really cold - but not quite 0F/-20C), my block heater won't kick in because of that dang sensor on the block heater.

 

I'd like to bypass the sensor - anyone done it? If so, is there a how-to or another posting on how someone did it?

 

I'm getting tired of waiting 15 minutes for my truck to warm up and frozen butt cheeks on the way to work. Not to mention, it also doesn't blow any hot air til it warms up.

 

I know, ask me again why I'm living in dang place that is frozen half the year....

[ColoradoSkiCountry]

You may just consider taking out the old one and putting in an aftermarket one, not sure if you can bypass the sensor on the factory deal.

 

I notice than when its a little cold here (or really cold - but not quite 0F/-20C), my block heater won't kick in because of that dang sensor on the block heater.

 

I'd like to bypass the sensor - anyone done it? If so, is there a how-to or another posting on how someone did it?

 

I'm getting tired of waiting 15 minutes for my truck to warm up and frozen butt cheeks on the way to work. Not to mention, it also doesn't blow any hot air til it warms up.

 

I know, ask me again why I'm living in dang place that is frozen half the year....

[peterupnorth]

Forkster- I'm a full day drive north of you where -30 is a warm day and -60F is not uncommon. I'd like to smack the EPA people on the side of the head; it's not

GM's fault. First cold day I owned my 2008, the battery froze solid because it apparently saves the planet by NOT fully charging the battery. So now I have to use a heated battery blanket (which of course burns electricity all night...duh). And even if you do bypass the sensor on the block heater, it apparently is only a 400 watt job, can't even tell if its working. (Seems to me there is some reason one cannot install an inline coolant heater....)

The guys that work in the bush here are so ticked with these new "save the planet" features that they don't ever shut off their trucks anymore for fear of being stranded.

Luckily I've reached the point in life where I don't have to go anywhere so it's parked when it gets cold. Or push junk aside and use the garage.

[Forkster]

NTW eh Peter? I was afraid of that - being forced to replace the entire block hear. Alright, I'm going to look at maybe getting a battery blanket and maybe something else to keep the engine warm. Calgary was the coldest place in Canada a few days last week (-30C and lower).

 

Good to know i'm stuck with my 'green' block heater which means I'll be running my truck longer to warm up in the morning.. .what blockhead thought of that idea?

[pilsner]

Im in the same boat with my truck. I run back and forth between Edmonton and Mcmurray.

The last thing I need is a block heater that is crap.

I've talked to countless GM dealers, and they wont bypass it.

I haven't talked to them about taking it out, and replacing it with an aftermarket one.

 

None the less, it definitely sucks.

[00Silverado4x4]

Well you could always do the back yard mechanics way & cut off the existing end & put a standard plug end on. I thought about doing that to mine, but then I moved to Georgia where it just doesn't get that cold. Of course you would have your block heater running non stop all night, but it's all in how much you want to pay for electricity, or get a timer.

[Forkster]

 

 

Well you could always do the back yard mechanics way & cut off the existing end & put a standard plug end on. I thought about doing that to mine, but then I moved to Georgia where it just doesn't get that cold. Of course you would have your block heater running non stop all night, but it's all in how much you want to pay for electricity, or get a timer.

Is it the plug end that's the culprit? Heck, that's a 5 minute job for me.

[MS3DALE]

Its the plug end.

[uchi]

from what ive read on here the plug end has a blister looking thing, mine has one, thats the sensor, cut that off, put a new one on and youre all set. the thing wont kick in till its like -15 or soemthing like that. i know now it dips a few degrees below zerop and i hate getting into a cold truck. so ill likely cut mine off soon once i find a plug i want to use for it and put it on a timer in my garage. have it kick on for the last few hours in the morning or so.

[peterupnorth]

Is it the plug end that's the culprit? Heck, that's a 5 minute job for me.

 

 

Ahhh.....I was going to do that to mine and didn't. I happened to read on one of the forums, likely this one, that cutting off the plug and replacing will

cause issues, and check engine light. They suggested slicing open that thermostatic plug and bypassing it somehow to fool the computer. Hey , I'm no

mechanic....just what I saw and thought I'd pass it on.

Has anyone actually changed that plug and had no issues?

 

Peter.

[impalabelt]

Sitting here in Alaska as I type, the block heater on my '08 kicks on like a champ right around 31 F (~ 0 C). Never had a dead battery on cold mornings as of yet, though I must admit the thought has crossed my mind a few times as the temperature hovers around -6 F lately, but it still turns over like its a warm summer's day? I do have to agree that the whole "temperature sensor in the block heater plug" concept is a bit of a turnoff. The dealership that did my block heater install made some mention of the fact that "standard block heaters" can't be used or the ECU will throw error codes? Any truth to this fact that someone in the know may be able to shed a little more light on?

 

Cheers!

[minibike132]

Sitting here in Alaska as I type, the block heater on my '08 kicks on like a champ right around 31 F (~ 0 C). Never had a dead battery on cold mornings as of yet, though I must admit the thought has crossed my mind a few times as the temperature hovers around -6 F lately, but it still turns over like its a warm summer's day? I do have to agree that the whole "temperature sensor in the block heater plug" concept is a bit of a turnoff. The dealership that did my block heater install made some mention of the fact that "standard block heaters" can't be used or the ECU will throw error codes? Any truth to this fact that someone in the know may be able to shed a little more light on?

 

Cheers!

 

The fact that it will throw error codes is the reason the EPA mandated the thermostatic plugs. But the reason it will throw error codes is because the start up perameters are EPA mandated as well.

 

If the vehicle off time has been many hours (say all night) and the air intake temp sensor reads -10 but the coolant sensor reads +70 then the PCM thinks there must be an issue with one or the other sensors or their circuits. This causes the PCM to default injector pulse widths and ignition timing to something other then what is optimal for the ambient temp untill the vehicle reaches closed loop.

 

I would think this could be done by manufacturers if they monitored the block heater current and made adjustments in the PCM if the heater were working prior to startup. That sounds like it would take some money and I don't know of a manufacturer that does this yet. I also don't know if the EPA law would allow it.

[impalabelt]

Sitting here in Alaska as I type, the block heater on my '08 kicks on like a champ right around 31 F (~ 0 C). Never had a dead battery on cold mornings as of yet, though I must admit the thought has crossed my mind a few times as the temperature hovers around -6 F lately, but it still turns over like its a warm summer's day? I do have to agree that the whole "temperature sensor in the block heater plug" concept is a bit of a turnoff. The dealership that did my block heater install made some mention of the fact that "standard block heaters" can't be used or the ECU will throw error codes? Any truth to this fact that someone in the know may be able to shed a little more light on?

 

Cheers!

 

The fact that it will throw error codes is the reason the EPA mandated the thermostatic plugs. But the reason it will throw error codes is because the start up perameters are EPA mandated as well.

 

If the vehicle off time has been many hours (say all night) and the air intake temp sensor reads -10 but the coolant sensor reads +70 then the PCM thinks there must be an issue with one or the other sensors or their circuits. This causes the PCM to default injector pulse widths and ignition timing to something other then what is optimal for the ambient temp untill the vehicle reaches closed loop.

 

I would think this could be done by manufacturers if they monitored the block heater current and made adjustments in the PCM if the heater were working prior to startup. That sounds like it would take some money and I don't know of a manufacturer that does this yet. I also don't know if the EPA law would allow it.

 

 

Fantastic, insightful, and exactly what I was looking for! Thanks so much sparkstech! You rock!

[impalabelt]

Okay... just a follow-up as this thread "piqued" my curiosity. I stand completely corrected and slightly perturbed...

 

It's currently 16F (balmy by most accounts lately) here in Alaska, I went out and plugged the truck in, checked for heat AND voltage... I got nothing???

Not sure what was so special about the last time I checked? Probably just me.

 

However the local dealership still seems to think these things activate at around freezing (32F)?

 

Anyway, I realize this is starting to become a "clone" of another thread so I won't get into any more details. But I just wanted to correct my earlier statement.

 

Cheers everyone and thanks for such insightful information!

[atsbob]

EPA is a US regulatory agency so why are they dictating what goes on our vehicles in Canada??

 

"The U.S. Environmental Protection Agency (EPA or sometimes USEPA) is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress."