LB7: P0380 aka ECM Problem

[av8or]

Hello all,

I was wondering if there is anyone in Southern Wisconsin (Portage to Janesville)who can repair an ECM. Trouble Shot all wires and glow plugs for continuity and voltage. The only thing left in the tree is the ECM. Starts hard when cold and winter is a coming.

Thanks in advance,

av8or.

 

[Stancedlb7]

It's not close but socal fixes em

 

[av8or]

Thank You. I was wondering if there was a way I could fix it myself? Should I get a new one?

 

[TheBac]

You checked the relays and GPCM too?

 

[av8or]

GP control =new OEM from Rockauto. Control circuit, 12 volts& ground has continuity. Wire from gpcm to #7gp has continuity both bus bars (ds&ps)new/good, glow Plugs (8) Bosh new. Only thing left is ECM. Wire from # 1 across top of engine to #2 checked good.

 

[THEFERMANATOR]

Just because you put in a NEW relay, don't mean it's a GOOD relay. Diagnose the issue, make sure the ECM is sending or not sending the signal to the GPCM when commanded to. Make sure the trigger wire is hooked up so the ECm can see if the glow plugs are on. Also make sure you have power to the GPCM WHEN it is commanded on. MANY have made the mistake of touching a test light to the hot stud and seeing it light up, and assuming the feed wire is good. Hold the test light to it when you command the glow plugs on, and all of a sudden it doesn't light up. Have you tried manually jumping the glow plugs on to make sure the system minus the ECM is working? Sounds to me like your going down the list of parts that could cause the problem, rather than diagnosing the issue at hand.

 

[av8or]

Just because you put in a NEW relay, don't mean it's a GOOD relay. Diagnose the issue, make sure the ECM is sending or not sending the signal to the GPCM when commanded to. Make sure the trigger wire is hooked up so the ECm can see if the glow plugs are on. Also make sure you have power to the GPCM WHEN it is commanded on. MANY have made the mistake of touching a test light to the hot stud and seeing it light up, and assuming the feed wire is good. Hold the test light to it when you command the glow plugs on, and all of a sudden it doesn't light up. Have you tried manually jumping the glow plugs on to make sure the system minus the ECM is working? Sounds to me like your going down the list of parts that could cause the problem, rather than diagnosing the issue at hand.

You did not read my previous post.

 

[THEFERMANATOR]

You did not read my previous post.

Yes I read you have put in a new controller, new glow plugs, and checked a couple of continuity checks. Have you verified the GPCM is sending the signal back to the ECM when on or not? Have you hooked up a bi-directional scanner and commanded it to? If the ECM detects a problem in the glow plug circuit like a simple problem with the signal wire, it will disable the glow plug circuit. Have you backprobed at the ECM to see if the problem is actually the ECM or not? Check to make sure the glow plug on signal wire is good to the ECM itself, also make sure the command wire at the ECM is good to the GPCM as well. Your post comes off as more I threw some parts at it, checked a couple connections at the controller, and it still isn't working. I know SOCAL can fix the ECM's, or you could find a used one for about the same amount of money(but then you are gambling on a used one). Just don't want to see you spend the money for an ECM, and have the problem persist. Also I would ditch the BOSCH glow plugs, and put in a set of BERU plugs(AC DELCO's are made by BERU).

 

[av8or]

I found the problem...... 175 Amp fuse between battery and Glow Plug Controller. It tested good the first time I checked it but I pulled it out and checked it again it was bad, no continuity. Picked it up w/ the Multi Meter still attached it tested good again and then suddenly bad. There was something inside the fuse causing the fault to be intermittent. Problem solved...Problem staying solved

So the solution to my DTC P0380 was a 175Amp Fuse.

 

[THEFERMANATOR]

I found the problem...... 175 Amp fuse between battery and Glow Plug Controller. It tested good the first time I checked it but I pulled it out and checked it again it was bad, no continuity. Picked it up w/ the Multi Meter still attached it tested good again and then suddenly bad. There was something inside the fuse causing the fault to be intermittent. Problem solved...Problem staying solved

So the solution to my DTC P0380 was a 175Amp Fuse.

Thats why I posted in post #6 to check for power while the plugs should be on. The 175 amp fuse will leave a carbon trail when it burns which will test good with a test light, but when you put an actual load on it it will drop to nothing. Glad you got it fixxed. Like I said in #6, MANY have made this same mistake because of that 175 amp fuse popping from a shorted bus bar.

 

[bswanson25]

I have the same code that came up in my 2003 duramax and I am trying to figure out the same issue. Where did you buy the 175 fuse? I cannot find it anywhere.

 

[av8or]

I got the fuse at O'Reilly's. I had to pull the fuse block shroud off to replace it.

Part # MEG175BP
av8or