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2009 DTS
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Discussion Starter #1
Hi all
SO my 09 DTS has the burning fuel pump relay problem. I did a search and read all the info from here and the Buick site that was linked in one of them. But none of them seemed to really answer the question of how to permanently fix the issue. I tried what was said to be an updated relay with a different AC #. I installed it and it got just as hot as the old one and lasted less than a week. I checked the numbers between the old and new and they are the same. I now have a Bosch relay wired in to get my car running. I would like to fix this correctly, but don't want to shell out the money for a new fuse panel if I'm just replacing it with what was in there and failed. So I guess my question is. Is the new fuse panel made out of a higher temp plastic and what assurances are there that this won't happen again in 40k miles? Is this going to be something to replace every 40-50k miles? I've never had a car with burning melting fuse panel/relay and this is very disappointing in a car that is suppose to be high end. This is my first time as a Cadillac owner and if there is no updated parts to permanently correct this it will surly be my last.
Thanks in advance
Jeff
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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Hot relay would have to be either high (contact closing) solenoid supply voltage or excessive current draw across the switched contacts.

If your car has a fuel pump module inspection hatch in the trunk floor, open it and check the fuel pump module electrical connector for cleanliness/tightness - you're looking for a high resistance connection.
 

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Had that problem last year on my wife's '10 DTS, ended up needing the fuel pump, fuse block and harness replaced. Luckily, the car is still under warranty.
 

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2009 DTS
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Discussion Starter #5
Thanks for the reply's all. I think I may be asking this the wrong way. From my way of thinking on this. The fuel pump circuit is a 20 amp circuit. The 20 amp fuse is not blowing so there for it must be less than a 20 amp draw. So if it's drawing say 19 amps this is enough amps to melt the relay and fuse panel but not blow a fuse should this be a 15 amp circuit? when I replace the fuse panel ( which I think is absolutely ridiculous to have to do) is it going to melt as the new pump gets some age on it? Has the fuel pump been redesigned to eliminate the issue or has the fuse panel been made out of a higher temp plastic that can handle a close to 20 amp load. I know that the relay with the new number is the same as the original so is there a different relay that should be used that can handle 20 amps? Can anyone out there that has 100k or more on there car and not had this problem check out the amp draw to se if those of us that have this problem are getting different readings? Or if you have a different relay? I ordered a new pump and I'm going to see if it draws a lower amp reading before shelling out money for the new fuse panel. I really don't like the idea of having to replace a fuel pump, relay and fuse panel every 50k. Sorry for the rant but I guess I just expected more from GM's high end brand. I really like this car, I want to love this car but it's really becoming a disappointment.
Thanks again
Jeff
 

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2009 DTS
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Discussion Starter #6
A couple more question's I have. I noticed that there is a recall on STS and CTS models about the fuel pump melting connectors and burning a hole that lets gas pump out. How different are the DTS pumps from the other 2 models? and could it be the same problem just melting/burning in a different area? How many DTS's have to have this problem before a recall goes out?
 

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2009 DTS
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Discussion Starter #7
Ok so when I got home from work today, I pulled the back seat to do an amp check. I wire the meter in series for the pump pwer wire. I took the hot wire and attached that to the positive lead on the meter and the negative meter lead to the relay hot terminal. And the reading was 7.56-7.64. Did I connect the meter correctly? this seems really low to be creating enough heat to melt a fuse panel and rely. I was expecting a lot higher number.
Thanks again
Jeff
 

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2008 DTS
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107 Posts
I had the relay or fuse go on my 08 dts. dealer changed relay/fuse and panel under warranty. all is well. not sure whay the fue panel has to do with it. however, that is what dealer did. fuse panel is under the rear seat.

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too many.
A couple more question's I have. I noticed that there is a recall on STS and CTS models about the fuel pump melting connectors and burning a hole that lets gas pump out. How different are the DTS pumps from the other 2 models? and could it be the same problem just melting/burning in a different area? How many DTS's have to have this problem before a recall goes out?
 

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It's not just the current, but resistance, Ohms law. If you have a dirty or corroded connection, even with 7 amps of current, you essentially have a heater which will avalanche and eventually destroy itself. And the fuse will never blow. This is why many houses burn down. A previous overheating condition can corrode the contacts in the fuse block which will cause the failure again. That's why the correct fix is to replace the pump, relay, and block.
 

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Please find below my experiences with fuel pump/relay/fuse box problems on my 2010 Buick Lucerne. The Lucerne and Cad DTS come from the same factory so this is relevant

Symptoms - The car cranks but does not start. I have had the car into the dealer 3 times and purchased spare relays and spare fuse box from them. Car became very unreliable...never knew when it was going to start. I replaced fuel pump relays 8 times until my third (and hope final) visit to dealer (Barnes Wheaton GM in South Surrey BC). Total bill so far about US$1700. 1st visit (Sep 15 2015)- they replaced fuel pump and relay. Car ran until..... 2nd visit (Dec 01 2015) - they replaced fuse box with used fuse box from Detroit because GM did not have any new ones at any warehouse (Canada or USA)!!! They read bulletin 15-NA-051 that referred to fuel pump relay problems due to rear seat clip and modified seat clip so it no longer protruded into fuse box cover. After this visit whenever the car kept on cranking past the usual quick start, I would stop cranking right away and check the fuel pump relay which was always fried. This happened about ~5 times until..... Jun 22 2016 - Visited dealer (after my phone calls not answered) to discuss repeated problem and possible causes with Barnes Wheaton Service Manager - he reviewed the problem with me for 1+ hours and found a deep mark in fuse box cover that indicated that the used fuse box installed in my car on Dec 01 had been in contact with the seat clip probably before being installed in my car (since the seat clip in my car had already been trimmed back.) 3rd visit ( Jun 23 2016) - they checked wiring between fuse box and fuel pump carefully at my request and replaced the used fuse box with new one I had purchased to keep on hand due to unreliable starts. So far after 15 starts it still works and I am a little bit more confident that we have found the problem (damaged fuse box terminal due to seat clip?), but only time will tell. One independent local mechanic mentioned that he had replaced fuel pumps etc regularly (1/week) because of poor quality gas available near our area. To eliminate this as a possible cause I have changed to super premium (no ethanol) to eliminate this as a possible cause. GM's lack of interest in this problem is disgusting...I have read over 60 complaints for this car from 2006-2011 models and no doubt this is a small sample. It is the most common complaint for the Lucerne on websites like this. Also: --The bulletin re the seat clip is not available publicly online, This is an easy home handyman fix and would save much frustration and dollars. -- Despite the fact that this was a common and serious problem with this car, GM did not stock new replacement fuse boxes. This prolonged my problem.

- Clive R., Delta, BC, Canada
 

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2006 DTS
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131 Posts
Poor ethanol, gets blamed for everything from flat tires to the A/C not working.

No reason the fuel pump relay has to be in the fuse block. Extend the wires, put new contacts on them and a new relay socket, use a new relay and tape it down.
 

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2007 DTS
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I agree with "Extend the wires", the high resistance was probably at the relay connection to the fuse panel. The heat is only generated at the point of high resistance. At 7.5 amps the pump is OK.
 

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It’s only for the Buick not the DTS

#15-NA-051: No Start Condition - Seat Bracket Contacting Rear Electrical Center (REC) - (Nov 5, 2015)
Subject: No Start Condition - Seat Bracket Contacting Rear Electrical Center (REC)

________________________________________
Brand: Model: Model Year: VIN: Engine: Transmission:
from to from to
Buick Lucerne 2008 2011 All All


Condition Some customers may comment on a no-start or stalling condition.
Cause The rear seat bottom frame may come into contact with the rear electrical center (REC) cover. The contact/interface results in varying amounts of deflection of the fuel pump relay (FPR). The movement of the FPR causes potential wear of the male terminals on the FPR.

Correction

• Install a low profile fuel pump relay.
• Remove material from the rear seat bottom frame, driver side mounting brackets.

Service Procedure:
1. Open the rear door and remove the rear seat bottom cushion.
2. Disconnect the battery.
3. Remove the fuel pump relay from the rear body fuse block and discard. Refer to Relay Replacement (within an Electrical Center).
4. Install the new low profile fuel pump relay to the rear body fuse block and install the cover.
5. Connect the battery.
 

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DTS 2010
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Jeff

I am in the same situation right now. Here are my findings. The full current load of the fuel pump is about 8 amps. The original fuse is 20 amps (I tested it with 10 amps fuse and the pump woks fine). To the best of my experience and knowledge, the original relay and all of the of this type relays are rated maximum 10 amps and probably less than that, depending of the quality and the manufacturer. Since the relay works continuously at almost 100% of its rating and there is not much cooling under the back seat the coil and the contacts generate heat. Because of that the contacts are loosing gradually their rated current caring capacity in exponential rate and as a result more heat is generated. Thus, the pins are getting hot and the deterioration is reaching to the fuse box sockets. The process is spreading and it is unstoppable and could reach the the harness.


Solutions:
1. I fully agree with you that installing a Bosch (30-40 amps current caring capacity) relay would solve the problem

2. Replacing the burnt fuse box (or find unused sockets with out replacement) and find the a relay with same pin configuration but working without overheating (20-30 amps rating). I have high hopes that I will find a relay with the original pin configuration and to handle the fuel pump load with no heating problems overtime (I have some leads for now).

Back to your "temporary" Bosch relay installation: I will appreciate very much, if you share some details of your work - picture, description etc., just to help me driving again.

Oliver
 

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Oliverpsmile

Private messages still not turned on. PM me with your email address and I will send you the doc’s.
 

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Thanks to danog's directions I managed to install cool running Fuel Pump relay outside of the fuse box due to deterioration of the sockets of the original 59 relay. Here are some finding that I'd like to share:

When I installed a cool working relay outside of the Fuse Box, (by tapping the wires -- control power to the relay 59 and the related 20 amp circuit to the Pump-- from the harness connecting block, I used this occasion to get some more testings regarding the Fuel Pump circuits. Here's what I got:

The Fuel Pump draws a little less than 10 amps.
I observed no change in the amperage during starting the engine (inrush current) or any change during high demand of fuel (gas pedal to the metal). It remained stable at a little less than 10 amps

I also connected three different relays in series providing power to the Fuel Pump to test the running temperature of the relays.
The relays are:
1. Original 10 amps 59 relay
2. ACDelco starter relay - ACD# D1741C/GM#19106615
3. ACDelco Bosch starter relay - ACD#F1755A/GM#19106616
I allowed some time (half an hour +) to reach their running temperature.
To measure the temperature, I used a contact thermometer (this is the only one I had, normally used to measure the temperature of the wine on my table) The outside temperature was 84 degrees F.

The results:
1. 158 degrees F
2. 115 degrees F
3. 113 degrees F

Comments; It appears that the original is the hottest. Given the fact that the relay is in the enclosure of the Fuse Box, it is quite likely that the temperature in this condition would be higher than 158 degrees F. And this high temperature is probably the reason behind the deterioration/almost destruction of my sockets.
It appears that the second and the third relays are similar as far as inside coils and contact ratings are concerned. The good new is that the second relay has the exact prong configurations as the original. So, if the 59 scockets are still good it would be good idea to replace the the 10 amps original relay with ACDelco starter relay - ACD# D1741C/GM#19106615

In my case, I had to install the relay outside the Fuse box because my sockets were burned.
 
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