Is there any way to test that heater, and does the glow plug celiniod control the heater,

---AutoMerged DoublePost---

And where does the heater plug in to ?

Check the wiring and ohm check the heater and test for short circuits,the heater plugs into the harness that runs along the firewall.

This diagram shows that the heater shares power with several parts as wll as the relay control from the glow plug fuse,not sure what years this applies to though:

Yah well the guys at Heath diesel said there was no fuel heater on the bottom of the fuel filter ? Would it throw this code if one of my glow plugs where bad , mine is a 98

How would they know if you have a fuel heater or not?

If the stock filter housing is there then it has a fuel heater,besides the heater is in the filter housing-not the filter.

What did the guys at Heath say the problem was?

---AutoMerged DoublePost---

Would also help if you were to confirm the year,make and model of truck and what engine it has.

Ok yah I took the heater out and it is shot, and they do not have any in stalk in all of Canada apparently. Would that cause that code to pop up , and how important is that heater ? And I have a 98 Chev 6.5 1 ton turbo diesel

Heater is not very important if antigell is used in fuel,just unplug the heater and as long as fuel doesn't leak from the wires you will be ok.

Also good to know you were talking about the truck shown in upper right of your post.

I think the code appears if the relay is not properly grounded through it's base but have not run into it personally-also don't have the manual close by to see if there is a trouble tree?

Can only find reference for duramax online and I know for a fact I have 1 glow dissconnected because it's broke off and on my 96 I do not get that code.

Hmm well I unplugged the heater and tried to cycle my glow plugs and my relay did not cycle so why would that happen

Is the fuse good?
Is coolant sensor good?
Is ground for relay good?
Is power from battery to relay heavy lug good?
Bit obvious but is relay harnness plugged in?

Fuse is good bc the glow plugs do work
Coolant sensor is good b I changed it
Ground is good bc I checked that twice
Power to relay is 12.2 Volts and th cable is good
An yes it is plugged in
I have about 6 sec of glow and the truck does start but I keep getting this code

Lost now-you said that the relay did not cycle and now you say it gave a 6 second glow?

With the fuel heater unplugged I would have thought that the code would go away-all I could find on the code applied to duramax so perhaps your newer truck than mine monitors glow plugs-maybe you need to discover if 1 new plug is bad?