Glow Plug light

[Montana55]

Truck has been great till the 7 year warrantee expired.. Now the glow plug light does not go out but if I wait 10 seconds in this very cold weather the engine stars great and the light goes out after it starts.. Also at the same time I got a code of bad glow plug for cylinder number 3.. I replace that glow plug and now it says number 4 is bad.. My question is even though I don't get a code for a bad controller is it bad too and should I replace all the glow plugs? I will add that this is a 2006 Sierra SLE and I don't know if this is true but Diesel RX who I got my glow plug from just told me the glow plugs are controlled by the ECM and not a glow plug controller.. Is this true?

 

[JoshH]

I wouldn't bother changing your controller for a couple of bad glow plugs. Just change the one that is throwing the code. There is a controller on the back of the driver's side valve cover that controls them, not the ECM. The ECM does tell the controller when to turn them on and off though.

 

[Montana55]

If when I get done changing the plugs where is a good place to get a controller if needed.. Somehow I have a feeling every time I change a glow plug it will show another bad one so I may as well change them all now.. I think I have 80,000 miles now

 

[Dozerboy]

I do mine 1 at a time, but its up to you. After 8 years I have done all, but 2 of them IIRC. Your damn lucky if you have gone this long and not had to do anymore then 1. Unless you don't drive your truck much.

 

[Montana55]

I do mine 1 at a time, but its up to you. After 8 years I have done all, but 2 of them IIRC. Your damn lucky if you have gone this long and not had to do anymore then 1. Unless you don't drive your truck much.

That make me feel good.. All I have done is change the oil religiously, lube and change fuel filter and air filter.. I average about 12000 a year till this year and it has gone down since I now have a little jeep.. I think I might just replace the other 7 and be done.. I did the first one without taking out the fender wells but I think I will just take them out now.. I do wish it would warm up

 

[THEFERMANATOR]

The glow plug light staying on to long is an indicator of a failed glow plug. The controllers for the LLY+ vehicles don't seem to have much trouble. It is essentially 8 relays built into 1 box. The rapid heat glow plugs seem to hold up well, so I would just change them 1 at a time like others above said.

 

[btfarm]

Or... As long as you have one fender liner or the other pulled back just do that side. I did that on the driver side. Still all original on the PS.