Fuel pump circuit, Help!
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Joined: Apr 2006
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From: Valencia Ca
Fuel pump circuit, Help!
I had the engine replaced in my c5 and I am now having issues with the fuel pump. I searched the forums and found information regarding the relays and jumping them to isolate the issue.
Indeed when I pulled the relay and jumped the connectors the fuel pump runs. I searched for SP122 which is the splice pack and for some reason I am getting a voltage reading out of it! When I checked the connections at g105 it appears a wire is disconnected from the grounding strap and I believe it connects to SP122. I was going to hook this back up, but it sparked when I touched the bolt and so I tested it with the voltmeter. It has 9v when disconnected from the grounding strap. Is this normal if the ground isn’t connected properly and I test it with a voltmeter? I am concerned about hooking up something hot to the grounding strap.
Indeed when I pulled the relay and jumped the connectors the fuel pump runs. I searched for SP122 which is the splice pack and for some reason I am getting a voltage reading out of it! When I checked the connections at g105 it appears a wire is disconnected from the grounding strap and I believe it connects to SP122. I was going to hook this back up, but it sparked when I touched the bolt and so I tested it with the voltmeter. It has 9v when disconnected from the grounding strap. Is this normal if the ground isn’t connected properly and I test it with a voltmeter? I am concerned about hooking up something hot to the grounding strap.
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Joined: Apr 2006
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From: Valencia Ca
Thanks for posting that video, I used it to get this far! I see that the problem is a lack of ground, but would expect to see voltage at SP122 if it’s not connected to the ground properly? I am concerned about hooking this up if it has power when the key is on, but I’m figuring that may resolve when it’s properly grounded and fix the problem. I’m not an expert by any stretch on electrical issues, but seems me that if it’s hot when the key is on a nd I connect it to ground it will short. Am I thinking about that wrong and my voltmeter is just supplying ground and completing the circuit for everything connected so it is reading voltage?
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From: Cape Coral, Florida
I had the engine replaced in my c5 and I am now having issues with the fuel pump. I searched the forums and found information regarding the relays and jumping them to isolate the issue.
Indeed when I pulled the relay and jumped the connectors the fuel pump runs. I searched for SP122 which is the splice pack and for some reason I am getting a voltage reading out of it! When I checked the connections at g105 it appears a wire is disconnected from the grounding strap and I believe it connects to SP122. I was going to hook this back up, but it sparked when I touched the bolt and so I tested it with the voltmeter. It has 9v when disconnected from the grounding strap. Is this normal if the ground isn’t connected properly and I test it with a voltmeter? I am concerned about hooking up something hot to the grounding strap.
Indeed when I pulled the relay and jumped the connectors the fuel pump runs. I searched for SP122 which is the splice pack and for some reason I am getting a voltage reading out of it! When I checked the connections at g105 it appears a wire is disconnected from the grounding strap and I believe it connects to SP122. I was going to hook this back up, but it sparked when I touched the bolt and so I tested it with the voltmeter. It has 9v when disconnected from the grounding strap. Is this normal if the ground isn’t connected properly and I test it with a voltmeter? I am concerned about hooking up something hot to the grounding strap.
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Joined: Apr 2006
Posts: 66
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From: Valencia Ca
The connection to g105 I believe is disconnected (after shop swapped engine). I see the grounding strap and the wire that I believe connects to SP122. When I check that disconnected wire I am getting power out of it. This occurs with the relay both in and out. I want to connect SP122 to g105, but I am afraid that this will cause shorts on other grounds.
am I thinking about right and I need to hook that up or if it has voltage definitely don’t connect it to ground?
the car actually seems to run fine if I remove the relay and bypass it, except that I did see a low oil level warning and checked the oil, it isn’t low.
am I thinking about right and I need to hook that up or if it has voltage definitely don’t connect it to ground?
the car actually seems to run fine if I remove the relay and bypass it, except that I did see a low oil level warning and checked the oil, it isn’t low.
Racer
Joined: Dec 2017
Posts: 331
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From: Florida
I had the same issue minus the positive voltage issue. Low oil level light, fuel pump wouldn't prime unless bypassed.
I had to take the battery and tray out and fix the SP122 ground splice pack in the taped wire harness. Mine was totally corroded
I had to take the battery and tray out and fix the SP122 ground splice pack in the taped wire harness. Mine was totally corroded
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Joined: Apr 2006
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From: Valencia Ca
With some help and assurances from C5 Diag over the phone I was able to get the car up and running again.
I figured I'd update this for anyone else searching in the future for a similar issue. I had checked the splice pack SP122 and the bus bar and connectors were cleaned and it didn't resolve the issue, but connecting the ground at G105 that was missed durin gthe engine reinstallation did resolve it. I didn't disconnect it again to ensure this was the problem and see if it recreates the voltage in the splice pack, but after connecting everything up and clearing all of the DIC codes I drove the car for about 10 minutes and no codes, no problems.
I'm happy that after all of these months I was able to get her up and going again!
I figured I'd update this for anyone else searching in the future for a similar issue. I had checked the splice pack SP122 and the bus bar and connectors were cleaned and it didn't resolve the issue, but connecting the ground at G105 that was missed durin gthe engine reinstallation did resolve it. I didn't disconnect it again to ensure this was the problem and see if it recreates the voltage in the splice pack, but after connecting everything up and clearing all of the DIC codes I drove the car for about 10 minutes and no codes, no problems.
I'm happy that after all of these months I was able to get her up and going again!
