2008 Buick Lucerne Fuel Pump Relay

[century76]

Interesting. Can you try something? Plug in the old relay and take the temp and compare it to the new one? Just want to see if it decreases the temp. If so, i may very well do this.

On a related note, someone over on the Cadillac forum hooked up three different relays and monitored their temperature. The original relay had a much higher temperature than the other two.

http://www.cadillacforums.com/forum...-through-2012/717810-fuel-pump-relay-s-2.html

 

[Longhorn299]

The problem is caused when a passenger sets in rear seat behind driver. The seat frame can press down on the fuse-relay box and damage fuel pump relay connectors and in my case melted the plastic fuse- relay holder. Fuse box located adjacent to Battery under rear seat.

Buick issued a Lucerne Service Bulletin in July 2016 for all Lucerne's. it instructs a technician to locate and measure a section of rear seat frame and cut it out, a picture is included. it also request replacing with a LOW PROFILE fuel pump relay.
I had my NO START problem in December 2015 while still in warranty. I have scheduled an appointment with my Buick Dealer for July 12, 2017 to modify rear seat frame at my expense. Must be done or problem will repeat unless no one is allowed to set in left rear seat. Sorry I do not yet have Service Bulletin Number.
Buick should issue a recall of Lucernes to address

 

[ironllama]

Buick should issue a recall of Lucernes to address

Yes GM should.

 

[TomP]

Both of my Lucerne's (2008 and 2010) have had this problem. I replaced the fuse boxes in both cases, and then I cut away the part of the rear seat that presses on the relay. I haven't had the problem again.

 

[Derrick999]

trim 5mm of the seat clasp off on the fuse box side, its pressing on the fuse box and creating the melting fuel pump relay

 

[Derrick999]

Hi folks,

I havent posted in a while but Finally replaced my 2002 Century with a 2008 Lucerne. Ive had this thing for about 2 months. I bought it used with 62k on it. Here is my problem -

After driving the car for about 50 miles in the morning I had to make another drive and got in the car and it would not start. It would turn over and all but no start. Everything seemed fine. I called my favorite repair place and had them tow it in. He found the Gas Pump Relay had basically melted/failed. So, He put in a new one and it got really hot according to him while the car ran. He did ohm out the gas pump and it seemed fine. Now Im curious as to if anyone else has heard of this problem or had it? What might you think it is?

Perhaps I should not have bought it but got it from a Buick dealer and couldnt find anything wrong with it at the time. I mean, I did all my research and all and ended up getting nailed anyway 😡.

Thanks, Everyone for reading.

Century61

You need to trim about 5mm of the seat clasp off on the fuse box side, it presses on the fuse box and fuel pump relay switch and causes it to arc and eventually melt and fail, if you look on the fuse box next clasp you'll see a wear mark.

 

[bobbo]

This is a major problem with the Lucerne, and Cadillac DTS. The heat also messes up the fuse box, requiring that to be replaced also. Some guy on ebay has sold about 2000 (sic) fuse boxes. I had to buy one last week. GM recommends replacing the original relay, P/N 15328866 with P/N 88953222 when making the seat repair. They do not address the fact that the fuse box may have to be replaced. Do a search for GM TSB No. 15-NA-051 for more info. My question, and the reason I am posting today, is, does anybody know if the new P/N relay runs cooler that the original?

 

[bobbo]

This is a major problem with the Lucerne, and Cadillac DTS. The heat also messes up the fuse box, requiring that to be replaced also. Some guy on ebay has sold about 2000 (sic) fuse boxes. I had to buy one last week. GM recommends replacing the original relay, P/N 15328866 with P/N 88953222 when making the seat repair. They do not address the fact that the fuse box may have to be replaced. Do a search for GM TSB No. 15-NA-051 for more info. My question, and the reason I am posting today, is, does anybody know if the new P/N relay runs cooler that the original?

 

[chartny]

Pic of the bracket but this is pas side since my driver's side has been modified by me. I put all my weight on one knee around all parts of the seat in the area and pulled the seat up and checked for any mark on the relay box cover, and also pulled the cover and the relay is fully seated. Now, measured as shown, and the distance from the front of the slot in the body to the back of the body it could rest on is 2 1/4" So half inch overhang to the rear of the body hump. My cutoff is more like the half inch of overhang as that cannot be of any use.
The alternate relay is know as "low profile" but I do not see how it can be unseated in the normal relay and cut back bracket.
-chart-

 

[2007LucerneCXL]

Buick lucerne did, does, have a issue with the relays under the seat. The seat would press into the relays and that would start the problem(s). There is a new shorter relay as a fix along with modified fix of the seat over the relays. If the relay box is damaged, look for melted areas under the relays, then a used non melted box and short updated relay may be the next option. Water or corrosion could be that at some point the battery vent tube wasn't installed, water has also been known to come in through the back bumper, check the spare tire well for signs. The battery cables have been also known to not be properly tighten, therefore creating another set of problems. Depending on who has worked on the car before it could just be sloppy workmanship or quick fixes as it was the simplest way.

 

[jerry r]

I have a 2008 same problem. The fuel relay blew twice in 2 months. Does anyone know for sure if its the fuel pump or the fuse box? The amps on the fuel pump come back at about 8.5 amps. I tested another 3800 V6 its fuel pump was only using 6.2 amps. Has anyone tested the amps on their fuel pump to see what it reads? I don't want to buy a $400 fuel pump and later find that it wasn't the fuel pump at all but the fuse block or something else. Any help would be appreciated! Thank you

 

[cciheap]

My wife inherited a 2008 Lucerne. It was babied throughout it's life and all prior maintenance was performed by the dealer. Because of this and several other issues, I must say that this car is very poorly engineered and built out inferior parts. After fueling on a trip far from home, it wouldn't start. Had the tow truck take it to his own shop. They replaced the fuel pump. It ran OK for about 1K miles and the same thing happened, again far from home. This time, the tow truck driver purchased 2 new fuel pump relays locally because he was 45 mi. from his shop and couldn't tow it because of missing parts to the tow truck. After inserting a new relay into the fuse block, I was able to drive with the tow truck following and made it about half way to his shop before the car quit again. He inserted the second relay and I was able to drive almost all the way before it quit a couple of miles from his shop. His partner came with another truck and towed it the rest of the way. The repair shop replaced the fuse block and was surprised that the local Chevy dealer actually stocked it, indicating that there was a demand for it. It seems to have solved the issue for now. I am continuing my membership in the auto club.

 

[buick bug]

Hi folks,

I havent posted in a while but Finally replaced my 2002 Century with a 2008 Lucerne. Ive had this thing for about 2 months. I bought it used with 62k on it. Here is my problem -

After driving the car for about 50 miles in the morning I had to make another drive and got in the car and it would not start. It would turn over and all but no start. Everything seemed fine. I called my favorite repair place and had them tow it in. He found the Gas Pump Relay had basically melted/failed. So, He put in a new one and it got really hot according to him while the car ran. He did ohm out the gas pump and it seemed fine. Now Im curious as to if anyone else has heard of this problem or had it? What might you think it is?

Perhaps I should not have bought it but got it from a Buick dealer and couldnt find anything wrong with it at the time. I mean, I did all my research and all and ended up getting nailed anyway 😡.

Thanks, Everyone for reading.

Century61

Yes, I had the same problem. I had to replace the circuit board the fuel pump relay plugs into because it melted, and the fuel pump because it was pulling to much current. It coat about $1200.00 at my local mechanic. Bad design.

 

[tjdean01]

It looks like this has not yet been solved. I just bought a new fuse block from GM (Nov 2018). The fuse that was in there is not the low profile one, it looks just like the original. I do have a low-profile one, however, and I will put that in to see if it runs cooler. Crazy that after all these years we still do not know the issue:

*It's not the back seat bracket but the issue continues after replacing the fuse block
*It's not the relay because new fuse block + new relay also has issues
*It's not the fuel pump unless if a bad fuel pump leads to a damaged fuse box and a previously damaged fuse box leads to a bad fuel pump and vice versa. This might be something to look at: once one thing goes bad it damages other parts that in turn damage something else in the system--perhaps we need to be replacing everything at once?

In short, I got this car from my dad and I'm getting rid of it as soon as possible.

 

[tjdean01]

We're all having this problem and NOTHING is solved. Perhaps when you get the melting, it damages something else in the system and this other damaged part leads to damaging the new parts we put in, and so on.

I just put in a new $300 fuse box (purchased November 2018) from the dealer and ran it 30 minutes today and the relay got HOT! I have the new low-profile relay but didn't put it in. Perhaps I could try putting that in there before this old style one melts the fuse box again. I'll follow up to let everyone know if it runs any cooler with new box + new relay. It's not sitting at my house but I should run out there now just to try it.

A family member needs a vehicle during a visit next week but after that, I think we're going unload this piece of junk!

 

[tjdean01]

As promised in my previous post, I removed the fuel pump relay that came in my brand new box from GM. I replaced it with the new low profile relay. The relay and some of the other tall black relays surrounding it got warm but did not get as hot as the normal sized original relay that came in the new box from GM. I guess we'll keep some spare relays in the car and drive it and see what happens. That GM refuses to address this is unacceptable.

 

[G-200948]

So, In essence you are saying its not actually a higher voltage that is burning up the relay but because of increased resistance at one or both of the posts coming from the supply side of the relay (were the burn is) it produces heat and actually overheats/burns the relay?

I take it you have encountered this before? Therefore the fix is probably a new fuse box under the seat.

How am I doing?

I Just replaced my fuse box on my 2011 lucerne. I noticed my fuse relay still gets warm but not as hot as before, is this normal?

 

[G-164786]

I know this is an old thread, but yes. I just replaced the fuse box in well under an hour. Just disconnect the battery, as always when doing electrical work. Then, take a couple medium flat blade screwdrivers and pry the retaining clips on both the front and back of the fuse box while pulling up. It comes out easily.

Take a picture of the plus and block location on the back of the box with a smartphone for reference, just in case.

There are 2 plus, that require a small flat screw driver to release the tabs, and then 3 wire blocks that are attached with a small cap screw in the center of each block. Remove the screw, take a the same small flat screwdriver and push down in the slots on the side of the plus to release the alignment tab while pulling up on the block.

Check the blocks to make sure there are no burned wired or connectors (unlikely) and install in same position on new box. Hand tighten the screws with a nut driver. They just need to seat all the way down. No need to over-torque the screws. Now snap the box back into place.

If your box came pre-loaded with fuses and relays, you're done. If not, move all of the fuses and relays out of the old box and install them in the same position. You'll need a new relay for the fuel pump if that was the problem.

Now reinstall the cover and connect the battery.

Start your car, and have a beer. You're done.

I did all this today it was easy. My relay fuse still.seems a bit warm not like before but warm. Is this normal or what

 

[mr. clean]

Wow...am sitting at home when I should be at work. Tow truck should be here any minute. Ran my 2010 Lucerne Super for 3 hours on the highway yesterday with no issues. It has 65000kms on her. Today it ran roughly for 15 seconds before dying; cranks like crazy but won’t start so am guessing it might be this issue. I will keep you guys posted with what happens with this.
Jeff

 

[mr. clean]

Wow...am sitting at home when I should be at work. Tow truck should be here any minute. Ran my 2010 Lucerne Super for 3 hours on the highway yesterday with no issues. It has 65000kms on her. Today it ran roughly for 15 seconds before dying; cranks like crazy but won’t start so am guessing it might be this issue. I will keep you guys posted with what happens with this.
Jeff

well, it took the tow truck over 3 hours to get here on a very mild day so while waiting I popped the back seat off, opened the fuse box and pulled the relay. It looked distressed. The dealer said it was going to cost $500CDN(!) for a fuse box PLUS a bit of labour. I asked if Buick/GM would do anything for me being it is a known issue; he got me to hold on the phone for a few moments. He found the TSB I mentioned and lo and behold, I picked the car up at lunch and no charge! Thanks all!