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2001 Eldorado - Fuel Level Sensor (Sending Unit)


hms200

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Hello all - Can anybody confirm for certain that only access to top of fuel tank for replacing fuel level sensor for 2001 Eldorado is via dropping the tank? I've read tips that some Deville's may have an access panel under rear seat but I've seen no such access tips for the Eldorado. I've actually taken a peak under both the trunk carpet and under rear seat and have found no access panels so I suspect dropping the tank is the direction I must take. Correct? Instructions I have for removal/replacement also describe dropping the tank. Just attempting to confirm there's are no other option/tip before attacking it.

Thx

Howard

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My problem/issue is same as what many describe across the web with Caddy's. Fuel level gauge doesn't read accurate once tank reaches a certain level and beyond. All research I've done on the symptom describes what appears to be a common failure of the fuel level sensor/sender to correct this problem.

Current Mileage: 114K

Service records (yep...I found um:)) indicate following:

10/20/2009 (105K miles) - Dealership replaced the fuel pump with supplied part from another company, Colorado Coach. Doesn't say is OEM, after market, used, etc and it doesn't mention specifically anything about the fuel level sensor...just says "Fuel Pump" in one sentence and "Fuel Module" in another sentence, referring to same activity.

02/09/2009 (98K miles) - (I quote straight from dealer service records): Fuel reading inaccurate. Gauge will fluctuate. Advise please. The fuel level sensor is intermittent open, provided an opportunity to replace complete pump module. Replaced fuel level sensor.

So...very odd entries here around area of this problem. Did first repair on 10/09/2009 fix the issue? Why was fuel module then replaced some 8 months later (unknown to me) and did that also include another fuel level sensor (new or used)? The original owner told me that dealership simply failed to adjust the float properly when they replaced the fuel pump assembly. I don't believe there is any such adjustment? The fuel level sensor contacts that convert fuel levels to the gauge ride on a swivel float arm...simple as that from what I see. All I can suspect at this stage is a bad sensor mudule was installed along with the fuel pump module (they are attached but each are individual servicable).

All this make any sense?

HMS

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The Eldo, being slated for termination never got any upgrades like the access hatch. There is no fuel level sensor adjustment.

Thx Ranger...that aligns to everything I've determined as well. All I can do at this point is just drop the tank and replace the level sensor. That's really all it can be I believe and I'm not willing to just live with the problem since my wife is the planned driver for the Eldorado.

HMS

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The Eldo, being slated for termination never got any upgrades like the access hatch. There is no fuel level sensor adjustment.

Thx Ranger...that aligns to everything I've determined as well. All I can do at this point is just drop the tank and replace the level sensor. That's really all it can be I believe and I'm not willing to just live with the problem since my wife is the planned driver for the Eldorado.

HMS

It could be sulfur corrosion on the fuel level sensor. I would buy a can of GM Fuel System Cleaner and add it to nearly an empty tank while you're at the gas station and then fill the tank. Drive the car until the tank is nearly empty. That should get the level sensor clean and restore proper operation.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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The Eldo, being slated for termination never got any upgrades like the access hatch. There is no fuel level sensor adjustment.

Thx Ranger...that aligns to everything I've determined as well. All I can do at this point is just drop the tank and replace the level sensor. That's really all it can be I believe and I'm not willing to just live with the problem since my wife is the planned driver for the Eldorado.

HMS

It could be sulfur corrosion on the fuel level sensor. I would buy a can of GM Fuel System Cleaner and add it to nearly an empty tank while you're at the gas station and then fill the tank. Drive the car until the tank is nearly empty. That should get the level sensor clean and restore proper operation.

Hey, thx for the tip Kevin. Have you ever personally experienced this issue and had it corrected with the cleaner, or has anybody ever reported same? It's definitely worth a shot. The fuel level sensor operational design is really very simple, though I'm sure the signal conversions are much more complex. There is like a plastic half circle with two strips of metal contact points mounted on it. The contact sensor is then mounted in the middle and the float arm extends off of it to allow the senor to swivel in a half circle along those contact points with the fuel level...very much like toilet tank float/regulator action. The sensor and contact points would appear to be completely exposed to the fuel and any potential contaminants, so your tip makes total sense if there may be anything fouling the surfaces of the sensor, or the swivel motion. The sensor itself is copper, but I don't know what material the contact point strips are made of honestly...doesn't look like copper though. In any case, can't hurt to give that a shot first before resorting to more extreme measures.

Howard

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my fuel gauge is also erratic below 1/4. err, don't get that low. i replaced pump 4yrs ago and found a lot of green corrosion on wire harness. pump was ok but tank was down so i changed it anyway. felt bad tossing old/good pump. i clean out my junk collection occasionally.

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my fuel gauge is also erratic below 1/4. err, don't get that low. i replaced pump 4yrs ago and found a lot of green corrosion on wire harness. pump was ok but tank was down so i changed it anyway. felt bad tossing old/good pump. i clean out my junk collection occasionally.

When you replaced, did you by chance remove the sensor from the pump assembly and inspect the contacts that I described for the green corrosion? Can anybody confirm that the fuel cleaner additive suggested (or any other product) can clean that gunk?

HMS

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Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Two weeks ago.... I told my friend in Ohio about the Techron.

He has a Chevy pickup that was doing the same thing...erratic reading on the fuel gauge.

He didn't believe it but decided to try it anyway.

He put TWO cans of Chevron Techrion in his tank and then filled it up.

His pickup has a 30 gallon tank. :) :)

He told me a few days later that it was working fine now.

Of course, you have to remember..it may work fine on some and not so well on others.

But it is sure worth a try...before dropping the tank.

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The Techron greatly improved the gage on my 96

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The Eldo, being slated for termination never got any upgrades like the access hatch. There is no fuel level sensor adjustment.

Thx Ranger...that aligns to everything I've determined as well. All I can do at this point is just drop the tank and replace the level sensor. That's really all it can be I believe and I'm not willing to just live with the problem since my wife is the planned driver for the Eldorado.

HMS

It could be sulfur corrosion on the fuel level sensor. I would buy a can of GM Fuel System Cleaner and add it to nearly an empty tank while you're at the gas station and then fill the tank. Drive the car until the tank is nearly empty. That should get the level sensor clean and restore proper operation.

Hey, thx for the tip Kevin. Have you ever personally experienced this issue and had it corrected with the cleaner, or has anybody ever reported same? Howard

The fuel gage in my '96 SLS started acting really goofy a year ago - the tank was full but the gage rapidly dropped to empty and the fuel level very low message came on the DIC. A couple of minutes later, the gage read full again. I used the GM fuel system treatment and in one tank of fuel, the gage was operating properly again and never did act up. I sold the car in October and the gage was still working fine.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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I was about to post the link to my topic on the global automotive fuel pump. Glad somebody did. Glad people still remember it!

My wifes 05 Buick Rainier just started reading inaccurately also. Just this weekend actually. On their forums they have some topics about it being a common problem. Of course this all leads to GM universally having problems with their sensors.

I wasnt aware you can change just the sensor. On the fuel pump I took out of my deville the sensor was part of the fuel pump assembly. For my wifes buick, the forums mention just buying the $35 sensor and replacing it instead of the whole pump. And many have done that. Only problem is the $35 sensor on ebay is from GLOBAL AUTOMOTIVE :wacko: eerrrghh, next cheapest is $75 from rock auto. But the fuel pumps look alot like these caddy ones.

Another reason I brought up the Buick. I put in 2 bottles of Techron saturday and the gauge went even more screwy. The needle faces straight down and each time the car runs it moves more and more to almost a complete circle. Apparently the "trailvoy" community doesnt have much success with the Techron. A cheap sensor replacement is the preffered fix.

If your car is higher mileage (over 100k) I would personally change the whole pump. Airtex is what I bought and it was great. It was around $110 I think which is good piece of mind you wont have to drop the tank again anytime soon or get stranded from a dead pump.

* 1966 Deville Convertible

* 2007 Escalade ESV Black on Black

* 1996 Fleetwood Brougham Black on Black V4P -Gone
* 1983 Coupe Deville Street/Show Lowrider -Gone

* 1970 Calais 4dr Hardtop GONE
* 2000 Deville DTS - Silver with Black Leather and SE grille GONE
* 1999 Seville STS - Pearl Red GONE

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As you can see the link below, Techron states that it:

Protects gas gauge sensors from malfunctioning

I believe that. Techron was recommended by the GURU who was on the Northstar Design Team, and I have had good success with it by adding a bottle at every oil change. In addition, the BULLETIN above from GM details the sulphur problem and how it impacts fuel level sensors.

It is important to read the directions on the bottle and to use it as recommended. We had extensive discussions of "fuel system / injector cleaners" and how you risked damaging your injectors and fuel pump coils and windings. Techron is the only product that the GURU would endorse based on their testing. But use too much and you can overdo it.

I have never seen it make a gage worse. But I would rather dose the system a bottle at a time at my oil change or every 3K miles than overdo it to protect the fuel pump and injector coils. I would hope that the somebody that used two bottles with poor results above had a 24 gallon tank or its over dosed, in addition, they only added it on Saturday and they are expecting MIRACLES 3 days LATER in COLD weather, what a laugh. The fact that it is AFFECTING the gage at all means that it is beginning to work.

The EASIEST thing to do is to TRY the TECHRON, it took me a couple of doses for it to begin to make changes. don't expect to put it in your tank and have a miracle happen in a few days, that would be idiotic.

Lets keep in mind that YES folks it may NOT always be sulphur causing an inaccurate reading but it could be something actually wrong with the gage, sensor or wiring, but to assume that a cleaner would DAMAGE a gage on the dash is a stretch.

http://www.chevron.c...itives/tcp.aspx

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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To wit:

I currently have an 01 Monte Carlo with a gage that either reads FULL or EMPTY, nothing in between. I will get the low fuel light but that is erratic also.

I have tried Techron concentrate with no results at all, no change. It should be noted that I am getting a P code related to the sensor, so its NOT expected that cleaning the level sensor would work

I plan to purchase a fuel level sensor for it, the Dorman part is $21, while the AC DELCO part is $114

However in my Deville, the gage was inaccurate, reading low, a few doses of Techron CONCENTRATE corrected that (not Techron Fuel System cleaner). The GM fuel system cleaner is also recommended

As I said, if its inaccurate its worth trying Techron, its cheap enough.

One other thing, it is also possible that using cheap crappy high sulfur fuel is the problem, try using better gas, Chevron along with others come with Techron. I have friends who put the cheapest fuel into there car regardless, and they argue with me that even though their car calls for Premium, regular is OK because they are cheap.. not realizing that they get better fuel mileage with premium and on a tank of fuel the savings by using regular is negligible, but in the meantime their PCM has retarded the ignition causing reduced performance.

See this link, for more info

http://autos.winnipe...=article&id=715

Here is another article that adds some info

http://www.epinions.com/content_2346164356

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Here is another link to the problem here, JohnnyG has experience in fuel, and it appears that BMW has problems with this also

http://caddyinfo.ipbhost.com/index.php?showtopic=18492

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I didnt state that techron DOES make your sensor worse. I am just stating mine has acted more weird since putting it in. Is it reading worse? I dont know, its just acting more weird. Would it have acted weird without the techron? I dont know.

And I installed 2 of the 12 gallon dose bottles in a 20-22 gallon tank so its not overdosing very much. I dont expect miracles but heck its worth a shot. Ideally you would want to add it at every oil change but we have only had the car a year and its low mileage so we didnt expect these problems. Even if I did start adding techron when we bought it I highly doubt it wouldve curbed the abuse and manner in which the car was treated the 5 years prior to us owning it.

I would also argue that the somebody above that uses techron every oil change might spend $30 every year protecting against a sensor failure that might only cost $40 to replace. If each sensor lasts 5-10 years or around 100k miles then Im not sure spending an extra $8 an oil change is worth the trouble. To me its not anyway. To somebody that cannot fix the sensor themselves maybe it is. I know people that go to all the trouble they can to prevent problems but they end up having problems just the same.

The option is there, its up to you if you want to use it. Dont let me be the judge for you. Im just here to tell you its a major problem with GM and dont buy fuel pumps for caddys from global automotive. ;)

* 1966 Deville Convertible

* 2007 Escalade ESV Black on Black

* 1996 Fleetwood Brougham Black on Black V4P -Gone
* 1983 Coupe Deville Street/Show Lowrider -Gone

* 1970 Calais 4dr Hardtop GONE
* 2000 Deville DTS - Silver with Black Leather and SE grille GONE
* 1999 Seville STS - Pearl Red GONE

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The Eldo, being slated for termination never got any upgrades like the access hatch. There is no fuel level sensor adjustment.

Thx Ranger...that aligns to everything I've determined as well. All I can do at this point is just drop the tank and replace the level sensor. That's really all it can be I believe and I'm not willing to just live with the problem since my wife is the planned driver for the Eldorado.

HMS

It could be sulfur corrosion on the fuel level sensor. I would buy a can of GM Fuel System Cleaner and add it to nearly an empty tank while you're at the gas station and then fill the tank. Drive the car until the tank is nearly empty. That should get the level sensor clean and restore proper operation.

If you compare a bottle of the GM Fuel System Cleaner with a bottle of Chevron Techron Fuel Additive, you can see that both bottles are exactly the same shape, color and have the exact same instructions for use. It seems highly likely the GM Fuel System Cleaner is a re-badged bottle of Chevron Techron Fuel Additive, but has a much, much lower price than the GM Fuel System Cleaner.

I hope this helps save some money.

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I have an 02 Chevy. Never had any problems with the fuel gauge. Summer of 2009 I put a bottle of Techron concentrate, and within 2 days, the gauge started moving all over the place, and has not worked since. I am not saying Techron caused the issue, rather it cleaned the contaminates that were probably keeping the thing going. I tried 2 more bottles in subsequent fill ups thinking it needed more cleaning to break some contaminates free, but no luck. Been using the trip computer to keep track of when to fill up.

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I have an 02 Chevy. Never had any problems with the fuel gauge. Summer of 2009 I put a bottle of Techron concentrate, and within 2 days, the gauge started moving all over the place, and has not worked since. I am not saying Techron caused the issue, rather it cleaned the contaminates that were probably keeping the thing going. I tried 2 more bottles in subsequent fill ups thinking it needed more cleaning to break some contaminates free, but no luck. Been using the trip computer to keep track of when to fill up.

:)... if it ain't broke...don't "FIX" it... :)

just kidding...^_^

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  • 4 years later...

Just thought I would post here rather than starting a new thread. Never had a gauge problem til I bought my 01 Eldorado.

It is usually pretty accurate til you get to half a tank then it just goes up and down randomly from full to half.

It bugs me because when I start the car it seems to be accurate (maybe)

and I get into the car and all of a sudden it goes up to full and wont come down.

I have run a good 6 bottles of Chevron Techron through it with no help.

I only run non ethanol premium fuel.

You cannot go by the range because it goes up and down with the gauge. I can imagine what it does to all of the readings, You can go through 10 gallons of gas in 2 minutes and it magically fills itself again.

I am waiting for the day I get too irritated with it and replace the pump assembly. This car constantly has something wrong so Ihave not been able to think about fixing this yet.

Kind of wish that GM would have recalled them.

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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