Trying to diagnose the fuel gauge on my W163, some help please

PJayUK

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Guys

My ML appears to have developed an odd problem with the fuel gauge, whereby it reads empty if I fill the tank right up. According to the US website this is a common problem. A temporary solution calls for fuse 5 to be pulled and then replaced from fuse holder RSE2. I had a look last night and I don't have the fuse block it states is under the passenger footwell near the glovebox. I checked the main fuse box under the bonnett and I don't appear to have a fuse for the fuel gauge, although F37 (I think) is for the fuel pump. I guess the full solution could be a new fuel pump sender but I don't want to spend that amount on the car this month. Could therefore anybody offer any advice on a temporay solution that might get it working for now? I was wondering if disconneting the battery for a while might achieve the same result, but I am a little unsure whether this approach is a good idea! Any ideas would be appreciated! Thanks all.
 

television

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You need to replace the fuel supply module when this happens, it is a listed fault.. this happens when the sensor goes more than 3 Ω. Is it that important ??
 
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PJayUK

PJayUK

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malcolm do you hane info on this fix? Is it an easy job?
 

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malcolm do you hane info on this fix? Is it an easy job?

Yes I have all of the info and yes it is quite easy,,I did not save it or print it off but I will do that for you when I turn on again
 

BlackC55

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The rear seats have to removed and they are a little awkward. The actual replacement is simple.
 
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PJayUK

PJayUK

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Guys is there a temporary quick fix for this, as per the fuse pull reset that the american site suggests? I'll certainly get it fixed in due course but I could do with getting it working even temporarily next week, due to a family holiday. Would a. Attery disconnect help?
 

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Guys is there a temporary quick fix for this, aper the fuse pull reset that the american site suggests? I'll certainly get it fixed in due course but I could do with getting it working even temporarily next week, due to a family holiday. Would a. Attery disconnect help?

I cannot see that there is,,the resistance goes high,,I do not know if the float part is exposed to the fuel,,if it is,,then injector cleaner works well
 
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PJayUK

PJayUK

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Is there merit in disconnecting and cleaning the block connector that is behind the wheel on the rear passenger side of the car? I read on one of the other forums that this could alleviate the problem temporarily.
 

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If the sender has to high a resistance I can see what playing around with the connectors will do
 

Alex Crow

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senders fail as stated. but we have seen corroded wiring at the connector as pjay suggests, once anyway. i would check the wiring first and perhaps save a lot of money. the connector is above the sender but pjay suggests it could be accessed through the wheel arch, worth a try but probably a squeeze.
 

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senders fail as stated. but we have seen corroded wiring at the connector as pjay suggests, once anyway. i would check the wiring first and perhaps save a lot of money. the connector is above the sender but pjay suggests it could be accessed through the wheel arch, worth a try but probably a squeeze.

The only thing against this is that it is a listed known fault, right down to a T
 

LYNALL

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Had same fault on a truck last week and you could see where the track had worn away on the sender unit, new unit wrong but a quick bit of soldering swapped the tracks over and all was well again.

Just brim the tank do 200 miles and fill it again until you can fix it, maybe even take a 5 litre can of spare fuel along with you, i alway do this on long trips has payed of a few times!



Lynall
 

Alex Crow

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The only thing against this is that it is a listed known fault, right down to a T

quite right, only goes awol with full tank. almost certainly sender then.
 


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