How is this for strange?

[Ry' N Jen]

Did the code go away once you started driving?

Yes.

 

[05kj6spd]

You could always hook a thermostat to a receptacle..(I am sure they make ones that plug in) then set it to turn on at 15 degrees and for a limited time or something. Would give you the advantage of heating up your car (which is a good idea) but only when needed.

 

[eradicator006]

When I have used the block heater for three or more nights (when it is above zero degrees Celsius/32 degrees Fahrenheit),
the check engine light comes on and produces a P0116 Engine Coolant Temperature Circuit Performance trouble code.
But the DTC is not reproduced when I leave the block heater unplugged!

I hate to revive an old thread but I had the exact same thing happen today. I thought it was going to be colder this morning (turned out to be only -6'C) and plugged in the jeep last night. I now have a CEL with a P0116 code. I'll see if the code eventually goes away.

 

[Paul M]

Like others suggested I'd use a timer to have the block htr run for 2-3 hours max before the morning...you are overheating the coolant (differential to outside air temp) then creating the error code because the computer gets confused. Our Dodge cummins diesel loves a block heater for cold temps and I can leave it on all night because it's made for it. But gas engines only need a little help, not all night, especially if it isn't that cold out.