When my oil temperature sensor was disconnected (because the clip broke) the glow plug like would blink once and remain steady and not start.

Every time I go to start, I look at my glow plug light for that blink and if it does, I know she won't start.

Most of the time she does not throw a code, but the last couple times she does throw a code afterward and the code is oil temp sensor.

I go under the hood, reconnect it and it works fine.

 

Thank you to everyone who has contributed info to this thread. Your thoughts and comments made it easy for me to troubleshoot my GPR problem.

A quick overview of my symptoms for you. Overnight temperatures were hovering in the upper 20s to low 40s for the past few weeks and I noticed the now familiar white smoke on trying multiple times before I finally got the truck started. I went through this for a few days before I began to think about the glow plugs or GPR being bad. I felt that there was such a radical change virtually overnight that I figured it would be the relay instead of the glow plugs. The WTS indicator was performing normally but that is just in indication from the instrument panel, not necessarily an indication of the GPR status.

I performed the tests listed above in the post by @ajbrown208 and determined that it was most likely (definitely) the glow plug relay. I've been dealing with a lot of other life issues lately so I didn't get right on ordering a new for a few days, I just shorted the two big posts on the relay for about 30 to 45 seconds and ran around to start. I'm ok with stuff like that for a short time as long as I know what the problem and the fix are.

So last Thursday night I would have sworn I ordered the NAPA GPR109 ($26.50 versus $50 for the recommended GPR205) online for pickup on Sunday at my local store. It took me until Saturday before I realized I didn't get a confirmation email so I called the store and the parts guy said that the GPR109 has been superseded by the GPR200 ($20, sweet!!!). And he had one in stock so I ran over on Sunday morning and picked it up.

I replaced it on Monday afternoon, but the truck was warm so I'm not sure it works other than connecting the pilot terminals to a battery and listening to it go "CLUNK". But I did also take the old one and tried the same test and it just drew a lot of current and no "CLUNK". The terminals are rotated 90 degrees from the stock relay but that turned out to not be an issue. I had read in another post here that the leads will reach and they do. So save yourself some $$$ and get the GPR200 if you need to replace your GPR.

Bottom line, I'm expecting to go out to my truck in the morning and have it start like normal.

Thanks again guys!

Tags GPR, Glow Plug Relay, GPR109, GPR200, White Smoke, Hard Start,