2008 Buick Lucerne Fuel Pump Relay

[century61]

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

 

[century61]

Well, 62 views and no replys. So, Hopefully this will be something not too bad to fix. Glad out of the 62 no one else has experienced this problem.

I will try and post back on what the mechanic does to fix this on monday. Thats when He said the car would be done. Basically he has to trace the problem all the way back up to the battery or whatever. He also told me this would not be pretty ($).

This happened on friday the 13th too!

 

[dcraig1000]

sounds like a definite wiring issue. relays just dont overheat unless there is a short to ground to the relay base, keeping it energized all the time. he must not have ohm'd it out properly or its an intermittent vibration problem.

 

[century61]

Well, I find out today from the mechanic about the problem with the fuel pump relay.

Ive owned this car for about 2 months now and I really do like it. But hope this will be the last problem for a while. What really makes me scratch my head is that Buick decided to put the battery under the back seat . Now that is pretty strange.

Ok, I will post what the problem is when I find out. Im sure some reading this post might be interested.

p.s. - I guess I should change my name to something else (century61 to ??) as Im selling my 2002 Century (3.1) with 260k miles on it. Thinking of asking 750 for it.

 

[polarzak]

What really makes me scratch my head is that Buick decided to put the battery under the back seat . Now that is pretty strange.

Cadillac and Buick have been doing that for some time. MY 2000 LeSabre had the battery under the back seat. Frankly I like the idea, having grown up with battery corrosion on the old style post batteries. The only one who did not like the battery under the back seat in the LeSabre, was my teenaged son who had to sit back there. Apparently the Lucerne has much better cushioning. 🙂 Regarding your problem, it is the first I have ever heard of it. I hope the problem is found and rectified.

 

[Buick Customer Service]

Please keep me posted on your progress. Feel free to contact me if you have any other questions. Thank you.

Tricia, Buick Customer Service.

 

[century61]

Hello and thanks to everyone that posted on this issue. I have finally gotten to the bottom of it!

Recap: The fuel pump relay would heat up to such an extent that it would basically melt/burn. This prevented the car from starting as it controls the fuel pump.

My Mechanic (Cobbs Automotive, Osceola indiana) worked very hard on this issue and found a few things that were not right.

1. The fusebox next to the battery in the back seat was heavily corroded underneath for some reason. He removed it and had to clean it and re-terminate a bunch of wires.

2. The main ground cable for the car was not making good contact. He had to remove it from the body and clean the body contact areas and reinstall it.

3. The fuel pump was drawing 12 volts and he replaced it with another and now it only draws about 7 volts. My thought is that the fuel pump was damaged somehow from the other problems.

He spent alot of time on the car and I really feel for him. I know what its like since Im in the service field for computer systems. He also gave me a really big break on the labor. Kept the cost at just over 700 bucks.

The car runs great now. But I did ask him if he felt that the dealer I bought it from in Warsaw, Indiana had tried to cover up the problem instead of fixing it and in his opinion "yes". But that is all opinion.

So, I dont know if I can go back to the Dealer and complain and get them to pay some/all of the cost of repair as it was just over their 30 day deal by about 2 weeks or so. So, Im probably stuck with the bill. But Im sure they were less than honest with me. My mechanic said that it looked previously worked on in that area.

I have to say, I tried to do all my research very diligently but there are just some things you cannot discover until after you own it. The price you pay for a used car I guess.

As for the battery in the back seat deal, Its different but Im sure I will get used to it. I think it would look funny though if I had to give someone a jump or receive one 🙂.

I like the car. Its the nicest I have ever owned. It handles and feels like real luxury! However, I dont think Ill ever discover what all the buttons do!😀.

Thanks everyone for your comments once again.

 

[cterrell73]

Glad to see you got everything worked out, hopefully you can enjoy your lucerne for a long time to come.

As for the battery being under the seat, yea it's weird but fortunately if you need a jump or giving a jump you don't need to remove your back seat. There is a positive terminal under the hood, and for the negative you can use a metal surface under the hood.

 

[polarzak]

There is a positive terminal under the hood, and for the negative you can use a metal surface under the hood.

Further info...the positive has a red plastic cap on it, and is located next to the fuse box, front left corner.

 

[polarzak]

If were me, I would definitely go back to the dealer. You just might embarrass them into giving you back any money you paid to them to look at the problem they couldn't fix, or maybe paying you back some of the bill to the good mechanic who found the problem. IF no luck, I would then write directly to GM. We tend to let the dealers off the hook far too much. I was reading an article about a fellow who took his 1970 GTO to a dealer just to pick up a part. He was having some trouble with the idle so he went to the Service Manager and asked his advice. He was told to leave it and they would hook it up to the diagnostics and see if the car had any trouble codes. Trouble codes in a 1970??? Needless to say, he burnt tires getting out of that place.
The mechanics of today are not like yesteryear. If they can't hook it up to a computer, they haven't a clue. No computer is going to tell them there is corrosion problem like you had, and most are not smart enough or unwilling to look further than a computer printout. When the warranties on my cars are up, and there is something I cannot or am too lazy to fix, I take my cars to a little shop out in the county, where the fellow there does have the computer diagnostics, but has the experience and wisdom to not to rely totally on a printout. And, he is a lot cheaper.
Sorry all. Rant over. Thank you.😀

 

[century61]

Another update to my amazing problem with my 2008 Lucerne.

The other night I drove down to the corner gas station to get gas and when I came out it would not start. It would turn over fine but not start. So, I pulled the back seat and pulled out the fuel pump relay and noticed that it had burned thru on one side.

The side of the relay that did burn thru was the main side. By this I mean the side that activates the circuit for the fuel pump. Iam assuming then that the problem is somewhere from the relay back to the battery - in general.

Sure would be nice if I could get a wiring diagram or repair guild for this. Anyone have a pdf repair guild??

Thanks,

 

[vintage42]

... What really makes me scratch my head is that Buick decided to put the battery under the back seat . Now that is pretty strange...

Like the 2008 Lucerne we just got, our 2003 LeSabre had the battery in the trunk. After two batteries and 12 years, the batteries and associated equipment under there were clean as new, and there was no trace of corrosion.
Decades ago, it was popular to relocate the battery of my BMW 2002s (a 1971 and a 1976) to the trunk.
Aside from the trunk, under the seat is the ideal location for many reasons.
1. Away from the destructive heat of the engine compartment.
2. Frees up space around the engine for access and maintenance.
3. Battery is always clean and dry.
4. Better weight distribution, especially in a front wheel drive car.

 

[vintage42]

... replaced my 2002 Century with a 2008 Lucerne. Ive had this thing for about 2 months. I bought it used with 62k... 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...

... I have finally gotten to the bottom of it!...
Recap: The fuel pump relay would heat up to such an extent that it would basically melt/burn. This prevented the car from starting as it controls the fuel pump....
1. The fusebox next to the battery in the back seat was heavily corroded underneath for some reason. He removed it and had to clean it and re-terminate a bunch of wires.
2. The main ground cable for the car was not making good contact. He had to remove it from the body and clean the body contact areas and reinstall it....

Perhaps you have a flood car. It is the only explanation for all this corrosion. There is no excuse for corrosion under the back seat in the passenger compartment!

 

[century61]

Perhaps you have a flood car. It is the only explanation for all this corrosion. There is no excuse for corrosion under the back seat in the passenger compartment!

I wouldnt doubt it. 😡. I tried very hard to cover all my bases. I got a carfax on the thing and really went over it at the dealership. But Im not a mechanic. This is the only thing wrong with it.

If I could get a wiring diagram of the car I could do this myself. But I dont have alot of funds right now and I havent found a reliable source for one. Perhaps some kind sole reading this post will offer one up??

Thanks for your reply,

coffee🙁

 

[vintage42]

... got it from a Buick dealer and couldnt find anything wrong with it at the time. I mean, I did all my research...

We got our 2008 Lucerne last month from a dealer, too. Like all the dealer's cars, it had free access to it's CARFAX report, which looked "clean". And I remember during the transfer process, among much paperwork, the dealer presented an affidavit that our car had not been in a flood. But then, our Lucerne was a CPO used car, "Certified Pre-Owned", with a 12-month bumper to bumper warranty.

 

[vintage42]

... Sure would be nice if I could get a wiring diagram or repair guide for this... If I could get a wiring diagram of the car I could do this myself...

Here is a site offering a wiring diagram for all cars including Lucerne, but it looks like it will cost.
http://www.eautorepair.net/app/YearsMakes.asp?gclid=CISx2qSSr68CFQfPKgodEHswmA

 

[polarzak]

Perhaps some kind sole reading this post will offer one up??

Thanks for your reply,

coffee🙁

One kind soul to the rescue. 😀 I have the whole 2006 manual in pdf format. Should be the same for an 08. I can send the wiring diagram to you. PM me with an email address and I will send it to you.

 

[2008Lucerne]

I have the exact same issue with my 2008 Lucerne. I bought the car about 6 weeks ago. After driving it about 1,200 miles ( I do a lot of highway miles) over about 4 weeks it left me stranded 2.5 hours from home.

I had the car repaired at a dealership. The mechanic found a bad spot in the wiring harness in the trunk leading to the fuel pump. He also replaced the Fuel Pump relay. $255 including the tow so I was ok.

Yesterday (after another 900 miles) I got in the car and drove about 300 yards, running very rough, I think it was starved of fuel. I pulled the new relay out and the plastic was melted through at the "30" terminal.

I inspected the wiring inside the trunk, so far found 2 nicks in the wires with exposed copper but they were not close. Still will not start. I am close to going back to a shop but I just dropped $500 on another wiring issue in my Ford F150. Really would like to figure this one out myself.

Any luck with yours Century?

 

[century61]

I have the exact same issue with my 2008 Lucerne. I bought the car about 6 weeks ago. After driving it about 1,200 miles ( I do a lot of highway miles) over about 4 weeks it left me stranded 2.5 hours from home.

I had the car repaired at a dealership. The mechanic found a bad spot in the wiring harness in the trunk leading to the fuel pump. He also replaced the Fuel Pump relay. $255 including the tow so I was ok.

Yesterday (after another 900 miles) I got in the car and drove about 300 yards, running very rough, I think it was starved of fuel. I pulled the new relay out and the plastic was melted through at the "30" terminal.

I inspected the wiring inside the trunk, so far found 2 nicks in the wires with exposed copper but they were not close. Still will not start. I am close to going back to a shop but I just dropped $500 on another wiring issue in my Ford F150. Really would like to figure this one out myself.

Any luck with yours Century?

First off, Lets keep sharing info on what we find.

This is how I figure it. Im not a mechanic. Im a computer engineer. What the heck, Same difference right? So, Looking at my relay I see it burned out on the main side. Melted right thru the housing of the relay. Therefore, The short on my situation has to be from the relay up to the battery. Thats my thinking anyways (?).

My mechanic already cleaned my fuse box under the seat and also replaced the fuel pump. Cleaned the ground wires.

I will keep you posted as to what I findout. My mechanic is suppose to call me tomorrow (4/18) sometime in the morning with an update.

coffee61

 

[92sub]

You do not have a short. A short would blow the fuse.
Most likely you have excessive voltage drop across the fuse relay terminal connection.
Once the original relay overheated (for whatever reason) the female terminal the relay plugs into 'enlarged' and now has poor contact. Your dropping voltage at this connection and the current is overheating the plastic.

If you cannot take the fuse relay center apart to REPLACE the female terminals you have two options:
1. Replace the fuse relay center with NEW.
2. Remote mount a new fuel pump relay OUTSIDE the center.
Obviously this second option is way outside warranty and dealer repair options. You'd need a electrical tech who really knows his stuff.