2000 5.7 gsi fuel pump relay problem

dubs283

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Looks to be quite a bit of corrosion on all the female connectors in the posted pic

Make sure everything is clean, no corrosion and the relay is making good, solid contact on all the connections
 

SD2600

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Good tip on clean tight connections…. I believe alldoge has helped me to hopefully find and resolve the issue with the mifi 3….
 

SD2600

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Well. My mefii was sent out and came back with a clean bill of health……

I just installed it and the same problem remains

Turn the key and I hear the main relay click but nothing for the fuel pump relay

Any thoughts?
 

SD2600

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Pin 30 85 and 86 have 12v with the key on for the fp relay….. shouldn’t pin 86 be the negative from the ecm?
 

alldodge

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Pin 30 85 and 86 have 12v with the key on for the fp relay….. shouldn’t pin 86 be the negative from the ecm?
Yes, but only for a couple seconds when key is first turned ON. Once ECM removes the ground you will see 12V again

Did you tell Bob that it was a fuel pump issue? Not that he needed to know but I'm assuming it would help make sure the problem your trying to fix
 

SD2600

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Yes I told Bob that my fuel pump relay ground was the issue… he said everything bench tested fine. He said i had an oil pressure code stored that he cleared.

I’m Not sure if the oil pressure code would stop the fuel pump as a safety feature
 

SD2600

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I’m unclear about pin 86….
I’m running an aligator clip from the negative batt terminal to the neg of my volt meter.

The fp relay is slightly pulled out so I can test the pins

Can u explain how or why pin 86 shows 12v?
 

alldodge

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Can u explain how or why pin 86 shows 12v?
Take a light bulb and put 12V on one side leave the other side disconnected. Put the negative meter probe on the negative battery post.

Now if you take the positive probe and put on either side of the bulb you will read 12V because the other side of the bulb is not connected to anything. If the other side gets grounded then one side see's 12V and other side see's zero volts

I’m unclear about pin 86….
I’m running an aligator clip from the negative batt terminal to the neg of my volt meter.
So when key is first turned ON you should see zero volts on 86 until the ECM removes the ground. If it stays 12V full time then either no ground is being applied or there is a bad connection.

Don't know the internal circuity but the ECM has 3 different grounds going to it. In pic note these are J1- 4, 5 and 20. It could be the one used for the fuel pump is one of these and not fully grounded

50 and 57 Gi GSi pin out.jpg
 

SD2600

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Ok I’ll re test pin 86… I didn’t have a second hand to turn the key on before. My 7 year old has volunteered for the task. I will also trace pin 4,5,20 to their grounds
 

SD2600

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Ok I’m reading 12.35v. With the key off. When my boy turns the key to the run position it reads 12.26v.
 

alldodge

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Ok I’m reading 12.35v. With the key off. When my boy turns the key to the run position it reads 12.26v.
There is no ground being applied by the ECM "or" there is a break in the wire.

Always thought Bob did a good test but not felling good about this.

Look real close at the pin on the ECM and make sure its making connection. If it is contact Bob and ask him about it, this is really the only thing that can keep it from working
 

SD2600

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Ran out of time today. I’ll take a look in the am and report back. Thanks again for your help dodge
 
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