Fuel pump fault

saleen836

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Help!
Took my 06 out yesterday and it drove perfect for the 5 miles I covered before arriving at the location where I was to collect and drive a groom to his wedding, went to restart the car and nothing, it just cranks but wont fire. A bit embarressing as the groom had to get his dad to drive him. Fault code reader is saying 'fuel pump driver module offline' ,I have had this problem before and have replaced the driver modules and have had no problems till yesterday. Did multimeter tests and there is 12v at both driver modules and there is also 12v at the top of the pump.
As there is 12v at the pump I am now thinking the fuel pump could be the problem or would this show as a different fault code or would the FPDM's prevent the fuel pumps actually working even though they have power?

Am just waiting for the car to be recovered back home and tomorrow I will pull out the fuel pumps and see if anything is amiss, I will do a search for GT500 dual fuel pump faults but any pointers will be very helpfull.
If it is the FPDM's failed again I will need to then figure out why they keep failing.

I need to find the fault as soon as possible due to me flying to Florida next Tuesday where I can purchase any parts and have them delivered to my hotel.
 

JeremyH

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I've seen fpdm plugs not fully seat or vibrate loose and need positive force to maintain it fully seated in the fpdm. The fpdm itself rarely fails. I would check that.
 

saleen836

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I've seen fpdm plugs not fully seat or vibrate loose and need positive force to maintain it fully seated in the fpdm. The fpdm itself rarely fails. I would check that.

Have already replaced both FPDM's after my previous problems, thought this was same problem.

Dug my stock fuel pump out after work today and after sorting out the wires for the stock pump plug, a quick flick of the ignition key and the stock pump fired up!
So will be removing the GT500 pumps tomorrow and replacing it with the stock pump, will then purchase a Keene Bell 'boost-a-pump' while in Florida next week, $300 and problem sorted :)
 

saleen836

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I have now removed the faulty GT500 dual pumps and all associated wiring and replaced it with the stock pump, car is now running perfectly! Will fit the BAP I have bought from a forum member and will fit that when I get home from Florida in a couple of weeks.
 

BruceH

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Are there any similarities? Like 20v baps being used? Not sure what I'd do if mine went out. Probably just get another one but maybe go with a single 465. Better yet go to a single stock with a bap and na.

Seems a lot of guys are starting to have gt500 pumps go out recently.
 

JeremyH

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Not sure the full details but I have had 3 or 4 requests to put upgraded pumps in gt500 hats due to pumps going bad in each case. Up until recently ive rarely seen the pumps themselves go out.
 

Dread53

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Just because it happened to me, check the inertia switch! I had power everywhere with key on and the FPDM disconnected, so I was at a loss to figure the problem. Switched driver modules and had the same issue, so I destroyed one of the modules to allow a pin check while running. As soon as the pump demanded voltage the inertia switch crapped out. New switch solved the issue (after I had rigged a bypass jumper for a few days), and I then wired in a relay to eliminate the high flow through the inertia switch. Good to go for the last 8 years.
 
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