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Discussion Starter · #1 ·
hey guys i have the PO380 code on. glow plug heater circuit A. i did some searching on here and figure I have either a bad glow plug or perhaps a whole module or something i need to replace. the last few nights have been pretty cold and the truck turns over for a long time before it starts now. does that mean its probably not just a glow plug but maybe the whole module? how do i tell for sure and what exactly is it i need to buy?? thanks!!
 

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as you said, p0380 usually indicates 1 or more bad glow plugs, g/p controller, or the 175 amp fuse. check the glowplugs first. take the rail off of them and get a test light, hook it to the pos side of the battery and touch the tip of each glowplug. if it lights up the glowplug is bad.
 

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Discussion Starter · #5 ·
i checked the 5 i could reach the easiest and every one of them was bad so i gave up and decided ill just order 8 new ones. this truck came from texas then arizona so who knows how long they been bad
 

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Im confused about this old post - hoping to clarify.
It seems like to me the P0380 code only is checking to make sure voltage is showing up on the backside of the relay which sends power to the glow plugs. I think this generally means the controller, wiring or relay. I guess you could have a short in a glow plug - but if you had a true short it would blow the fuse. So I don't think P0380 code without a blown fuse indicates plugs (for me it was relay).
Also - the light test doesn't seem right to me. If a new glow plug is 1 ohm it seems like the light test would light up with the 1 ohm in line plug and by the above post indicate a bad plug..
 

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Make sure your Injectors are going bad. Yes the same code came for me . Its was the first sign that one or more of my injectors were failing after i replaced all 8 GPs and the module. Just sayin. Hopefully not but it happened to me. I chased that code for a few weeks testing Ohms and voltage and first looking for a bad wire....
 
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