Can I Bypass the Water in Fuel Sensor?

[Smart4two]

Is there a way to MODIFY something so the computer detects the water in fuel sensor as functioning OK?

 

My Canadian 06 Smart Fortwo cdi has 1 fuel filter located in front of left rear wheel(under the removable plastic belly panel). I installed the old Water in Fuel Sensor in the new filter. Noticed some green copper oxidation and intended to clean it out/up with Q-Tip(Cotton swab/bud). There is 3 pins in connector. 2 pins broke away with a gentle brush up against them. They were Corroded through from the oxidation.

 

I need to use the car ASAP. Will the computer put the car in limp mode if the Sensor is not connected? Filter is not installed in the car yet.

 

Found some info on internet for about bypassing a 2 wire Water in Fuel Sensor. He said his sensor would detect water at 40K Ohm resistance. He put an 80K Ohm resister between the 2 probe wires. His dash warning light went out. Was not as Smart Car. I don't know how the 3 wire Water in fuel Sensor works. Best guess is 2 wires are for probes in the fuel and 1 wire is the ground. I was thinking of putting 80K resistor between 2 wires and 80K resistor on ground wire and then connect it to ground.

Edited February 1, 2023 by Smart4two
spell correction and correct sentance

[MikeT]

Nope, it won't go into limp mode, but the water in fuel light in the middle of the dash may illuminate.

[MikeT]

To be perfectly clear, European models did not have the monster fuel filter but rather a smaller inline filter with no H2O sensor. Hence it's not hard wired into the car's brain. There is simply the water in fuel light between tach and clock (centre of dash if you don't have those). Easily ignored.

[Smart4two]

Thank you MikeT.  At least I can install it now and either bypass the Sensor or get a used one eventually.

[Smart4two]

Thanks. I did not know where the warning light was located but saw the fuel warning light between tach and clock on continuously for months. Thought it was a malfunctioning low fuel warning!

[Willys]

IMHO....Unless you are electrically minded as in able to work in computers I wouldn't start messing with the electronics of these pain in the ass cars when it comes to the white smoke machine...so to speak.  IF this is your strength, then post up all you learn and over come....us cavemen who still remember the single wired vehicles of the past century are all ears....lol.   I have never owned a car that is so sensitive to electronic issues as this car, not looking to trade it by any means but just thinking out loud is all.
I would either buy the sensor new from somewhere other than a dealership unless they have a great price which for this I doubt or start searching wrecking yards for a good used one. I'd be asking for the fuel filter not the sensor to try and keep the cost of a used one down wink wink.   Do you have pick and pulls in your area.....?  OR maybe someone is parting out a car(Smart142  ?) near you that may give it for a good price?   This doesn't come up that often to be a high dollar figure I don't think, does it?  I haven't heard of one having the contacts breaking off before.?

Edited February 1, 2023 by Willys

[Nigel]

For a sensor call the dealer and ask.  Mercedes is reasonable on their prices compared to the other German auto makers.  If they’re not try contacting smart142 on this forum, he parts out smart cars pretty regularly and should be mail you one at a reasonable cost. 
 

Nigel

[Smart4two]

3 hours ago, Willys said:

"IMHO....Unless you are electrically minded as in able to work in computers I wouldn't start messing with the electronics of these pain in the ass cars when it comes to the white smoke machine...so to speak." 

 

Thanks. Good points/advise. I certainly had/have reservations about messing with the electrical and causing more problems. I had bought the fuel filter minus sensor already. Did not find the sensor problem until I put fuel in filter and installed the sensor. MikeT says the car won't go in to limp mode without the sensor connected. I also found out that the water in the fuel light had been on for months and possible was that way when I bought it early last year.

Edited February 1, 2023 by Smart4two
Placed my reply in wrong spot

[Willys]

I was only thinking about adding resistors etc to try and trick the computers which may create more or bigger issues afterwards.  Simply replacing these parts with new or better is just general maintenance...imho.

 

[Smart4two]

2 hours ago, Nigel said:

For a sensor call the dealer and ask.  Mercedes is reasonable on their prices compared to the other German auto makers.  If they’re not try contacting smart142 on this forum, he parts out smart cars pretty regularly and should be mail you one at a reasonable cost. 

 

Thanks Nigel; I installed the filter without sensor being connected. Will cover the warning light with a black sticker. I use a fuel additive regularly so any water in the fuel should be taken care of by that product.

Edited February 1, 2023 by Smart4two
placed my reply in wrong spot

[Smart4two]

I cut the old filter media in half. I don't think one of these filter can get more plugged than this one....!

I have put 10,000 km on the car since I bought it last Spring. I should have replaced the filter after buying

it since I did not know when it was due to be replaced.

[Willys]

Canadian Tire sells what I use mostly during the winter months, every other tank it gets 50mls  Diesel Kleen   I'm still working my way through their 4 litre jug of it...lol. It's been years!
Yes it comes in far smaller jugs but the price is better in this size...per tank.

 

Again to each their own as this is very much the same as a oil thread when comparing mechanic in a can....lol

 

[Henry]

About fuel additives.

I used Howes for years and found that it was hard to get any in the tank without spilling most of it down the side of the car.  Someone on here showed me how to simply pour it into the end of the fuel nozzle at the pump before adding fuel no more spilling.  what is considered the best additive currently, I have just been gifted a 45 gallon drum of Jet fuel so am looking for mostly higher lubricity and a cetane boost.

Jet fuel has a lower cetane rating than diesel.

Not wanting to hijack this thread so moderator please move it if it gets out of hand, 

Henry

[Smart4two]

13 hours ago, Willys said:

"Canadian Tire sells what I use mostly during the winter months, every other tank it gets 50mls  Diesel Kleen"

 

Diesel Kleen is good and likely has the same benefits as the product I use. I use 50ml of Lucas Upper Cylinder Lubricant in my Smart car per fill. I buy a 3.78 Litre jug. Can be used in Diesel and Gas. My p/u truck has a 26 gallon gas tank so uses much more of it! 

[Smart4two]

1 hour ago, Henry said:

"I have just been gifted a 45 gallon drum of Jet fuel so am looking for mostly higher lubricity and a cetane boost."

 

I put my fuel additive in a small vitamin bottle. Easily pours in to the tank. 2 Stroke oil could help with the Jet Fuel lubrication and a small amount of Acetone will up the cetane rating.

[MikeT]

Petrolabs diesel treatment here and the fuel nozzle is the obvious place to pour the additive in.

[Getfuzzy]

I use Lube Corp premium diesel plus (2ml/liter) for  a cetane boost between 9 and 13 points. I use a 100 ml syringe to get the right dose, about 40 ml/fill up and squirt it into the fill pipe.

[Willys]

For the container of choice for myself, cheap air tight and did i say cheap....dollar store small liquid containers that you would think wouldn't seal to save your life, do seal and have been working for over 2 years now...go figure!  They are just over the 50 ml size and yes simply dump into filler tube. I refill a couple at a time and leave them in the driver's door pocket.   Dollar Store.....unbelievable...lol

But I am going to try the med containers I get as they are structurally stronger and roughly the same size..not the round see through type but the hard plastic square versions...but will they not leak?   Hmmm...?

[Smart4two]

1 hour ago, Willys said:

"For the container of choice for myself, cheap air tight and did i say cheap....dollar store small liquid containers"

 

I'll check the dollar store ones. I use small plastic vitamin D bottle with screw on lid. Holds 100ml.

[450ken]

This is the best product I have come across HotShot Secret Diesel treatments, Diesel Extreme once or twice a year and Everyday Diesel Treatment at every fill-up.

 

[MikeT]

18 hours ago, Getfuzzy said:

I use Lube Corp premium diesel plus (2ml/liter) for  a cetane boost between 9 and 13 points. I use a 100 ml syringe to get the right dose, about 40 ml/fill up and squirt it into the fill pipe.

 

The Petrolabs bottle has a graduated (mL) squeeze chamber on it, so no need for extra vessels.

[Smart4two]

My car is running perfectly👍‍😎👍‍ with the Water in Fuel Warning Light on. I will never replace the Water in Fuel sensor unless I come across a Free or low priced fuel filter with one in it. The fuel filter removes water and my fuel additive prevents water issues anyway so I'm covered😉.

[Smart4two]

8 hours ago, 450ken said:

"This is the best product I have come across HotShot Secret Diesel treatments, Diesel Extreme once or twice a year and Everyday Diesel Treatment at every fill-up."

 

Specs look good on their website for the HotShot product and if used in small car it will last many many fills before emptying bottle. I've been using the Lucas Upper Cylinder Lubricant for many years in all my Vehicles. Used in small cars up to trucks with big CAT engines in them. I've experienced improvement in performance over time after using. Likely from injectors getting cleaned up and spraying better. 1.5 years ago I payed approx $30 Canadian for 3.78 Litre jug of the Lucas Upper Cylinder Lubricant additive at Inland Truck & Equipment Langley, BC. I have enough left to treat 20 gallons of Diesel for my Smart Car so getting some more very soon. I probably should expect a price increase!

Edited February 3, 2023 by Smart4two
Added a few sentances

[Mjolinor]

 

Do you have problems in Canada with dirty/inferior diesel?

 

I have never used any diesel additive in anything.

[Smart4two]

4 minutes ago, Mjolinor said:

"Do you have problems in Canada with dirty/inferior diesel?"

 

The fuel in Canada is not dirty/inferior to the UK. 05/06 Canadian Smart cars have one Fuel filter. Some or all have 2 filters in the UK. Recommended to change Smart car fuel filter ever 32,000 km. Look at the picture of my cut open filter. My fuel tank is plastic so would not be rust plugging up the fuel filter. I am going to guess my filter had 50-60,000km on it. I put 10,000 km on the car since I bought the car and did not know it needed replacing. Fuel injectors get clogged from hydrocarbons, sediment and other particles in the fuel. Happens everywhere in the World. Additives help clean the injectors and keep them clean/lubricated. Won't help a worn out injector much or at all though. Better fuel economy and performance with all injectors working proper. Can check some of the products mentioned here on the internet. The additives do a multitude of beneficial things for the fuel system.