Fuel Quantity Indicator Failure
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Fuel Quantity Indicator Failure
Like clockwork, my C43 has decided to pop another electrical failure right before service time......my fuel gauge has stopped working correctly. It's basically an intermittant erroneous reading of empty (or close to empty if light isn't illuminated) that seems to generally be happening on hot starts. Perhaps of note, or more likely by coincidence, this was first noted after my most recent trip to the gas station. Not knowing really anything about the w202 fuel system, does anyone have any idea what might be going on? Fuel float failure, CAN failure, ???? Thanks in advance....I'd like to try and take care of this myself so I don't have another $800 bill (for the windshield wiper motor last time).
#4
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No way to be sure without checking it electrically, but the most common point of failure is the fuel gauge sender in the tank. When in doubt, go with the moving part.
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Battery is 100%, or at least I don't have any reason to believe otherwise (easy cranking on cold start, no alternator warning light, etc). I figured it probably is the sender....is that a DIY kind of thing, or does it necessitate disassembling the fuel tank? I'd probably be up for that even, but most of my tools are 3000 miles away in storage unfortunately...
#6
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I think there are two senders at the bottom of the tank. I also think you need special tools to get them out and I recall there can be complications. Something to do with the fuel pump and something else to do with new senders possibly requiring version coding with the dealer's Star computer.
http://www.detali.ru/cat/oem_mb2.asp...SGR=015&SGN=01
All told, probably a good one to leave to a pro.
http://www.detali.ru/cat/oem_mb2.asp...SGR=015&SGN=01
All told, probably a good one to leave to a pro.
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Yeah, like I said it is due for a service so at least it's not inconvenient. Definitely seems to be a hot start thing.....anyone know if the sender unit a resistor type unit, or a float?
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#8
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The WIS says the first thing to check is that the sender isn't hung up on the fuel line and the lines aren't kinked. Per the C43 secton of the WIS, the R&R procedure is as follows:
![](http://www.marcusfitzhugh.com/CLK/DIY/photos/misc/C43rrfuelsender.jpg)
You did see the part about "no smoking", right?![Big Grin](https://mbworld.org/forums/images/smilies/biggrin.gif)
Post back whether this helps, if the line was kinked, hung up, and how you fixed it. THanks
![](http://www.marcusfitzhugh.com/CLK/DIY/photos/misc/C43rrfuelsender.jpg)
You did see the part about "no smoking", right?
![Big Grin](https://mbworld.org/forums/images/smilies/biggrin.gif)
Post back whether this helps, if the line was kinked, hung up, and how you fixed it. THanks
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190D 2.5 (x2), 190E 2.6, W202 C240,W202 C43 (C55), W210 E55, W212 E250CDI
Very common for these fuel senders to fail. The new senders (genuine at least) have gold contacts to prevent premature wear/corrsion. The contacts in the tank can be cleaned but since they are a little more labor intensive than other models to remove from the vehilce then it makes more sense to replace them.
I just had to do it to my car last weekend........not happy!![action](https://mbworld.org/forums/images/smilies/action1.gif)
Probably best left to a workshop to do because it's hard without a hoist.
I just had to do it to my car last weekend........not happy!
![action](https://mbworld.org/forums/images/smilies/action1.gif)
Probably best left to a workshop to do because it's hard without a hoist.
#10
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Same problem with my '99...fill the tank and the gauge read empty and the fuel light would remain illuminated. After 50-60 miles the gauge would then move to "full" but would remain "full" for 150 miles or so, then begin to drop rather quickly to 1/2. Really whacky! I read some posts here and was skeptical, but gave it a try and, in fact, the use of fuel injection cleaner does appear to solve the problem entirely! With this last tank, I drove until the fuel warning light went on, added 2 gallons and the light went off and reads just under 1/4 tank, then filled it completely and the gauge reads full!! YEA!!!
Last edited by JRbro; 05-21-2008 at 06:43 PM.
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Same problem with my '99...fill the tank and the gauge read empty and the fuel light would remain illuminated. Drive 50-60 miles and the gauge would then read full, but would remain at full for 150 miles or so, then begin to drop rather quickly to 1/2. Really whacky but I tried, and was skeptica, but in fact, the use of any sort of fuel injection cleaner appears to solve the problem entirely! Since the addition of Gumout injection cleaner, my gauge appears completely normal. The light went on last night, I added 2 gallons, and it went off and reads barely 1/4 tank. YEAH!!!
#13
The WIS mentions the gauge issue specifies replacement of the sending units with new ones that have gold contacts; $600-800... Apparently the oxygenates used in gasoline corrode the wiper contacts...
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yay....thats basically the average then. Not to sound cheap, but I'm not sure why MB can't make a car that doesn't charge you 800-1000 bones every 10 months for random electrical gremlins. And on top of this, I have a phantom A/C sensor failure....like it refuses to turn on the cold A/C air on occaison, and after shutdown and re-start its all good. Man I need to sell this piece of ****
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1967 Morris Cooper "S", 1983 911SC, 1997 Toyota Tacoma, 1999 HD FXSTB, 1998 C43
yay....thats basically the average then. Not to sound cheap, but I'm not sure why MB can't make a car that doesn't charge you 800-1000 bones every 10 months for random electrical gremlins. And on top of this, I have a phantom A/C sensor failure....like it refuses to turn on the cold A/C air on occaison, and after shutdown and re-start its all good. Man I need to sell this piece of ****
#16
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yay....thats basically the average then. Not to sound cheap, but I'm not sure why MB can't make a car that doesn't charge you 800-1000 bones every 10 months for random electrical gremlins. And on top of this, I have a phantom A/C sensor failure....like it refuses to turn on the cold A/C air on occaison, and after shutdown and re-start its all good. Man I need to sell this piece of ****
For the AC, have you gone through the diagnostics via the HVAC controller? Many times it's an inexpensive sensor. IHTH
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For the AC, have you gone through the diagnostics via the HVAC controller? Many times it's an inexpensive sensor. IHTH
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'98 C43 AMG. Obsidian Blk w/2 tone slvr/blk interior
Fly,
My C43 currently is in need of an evaporator, so dont feel bad about your AC issue. i had the EXACT same symptoms when my '97 C280 AC started acting up. Took her to the stealership and 1 evap temp sensor later i was back in comfort. 170 bucks but they didnt charge me for labor, so i guess in this case theyre just a regular dealership, no stealing that time, at least on the labor
My C43 currently is in need of an evaporator, so dont feel bad about your AC issue. i had the EXACT same symptoms when my '97 C280 AC started acting up. Took her to the stealership and 1 evap temp sensor later i was back in comfort. 170 bucks but they didnt charge me for labor, so i guess in this case theyre just a regular dealership, no stealing that time, at least on the labor
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For the AC, have you gone through the diagnostics via the HVAC controller? Many times it's an inexpensive sensor. IHTH
#21
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You'll have to try it. Hold in the REST button and see if the codes are available. I know my W208 has fewer codes available than the W209. I'm guessing the earlier the year, the fewer the codes.
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im tellin you, evap temp sensor. the AC would be running good and then all of a sudden the air would turn humid and not cold, this symptom will come and go intermitently until the sensor decides to go bad all the way... just replace it, its pretty cheap
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1999 C43