fuel gauge resistance range wrong?

[getman]

I did a search but didnt find anything that matched mine exactly.

I have a 2005 RXP215. The resistance range of my fuel tank sensor is between 0 ohms (full tank) and 90 ohms (empty tank). The problem is that my fuel gauge shows full tank at approx. 10 ohms and empty tank at 340 ohms !!!! (I measured by connecting a potentiometer). What is wrong with my fuel gauge? Thanks

 

[mkov608]

What is the original problem the caused you to tear into the fuel level sensor circuit? The most likely cause of your resistance readings is that the potentiometer you've connected doesn't match the linear resistance curve in your pumps fuel level sensor, and according to Wikipedia, it's more appropriately used to measure voltage (old school before digital multimeters) ... not resistance.

 

[getman]

the original problem is that i get an error "SENSOR", if the tank is full. The cause is a low resistance of the tank level float sensor (approx. 0 ohms). So I disconnected the sensor and connected a potentiometer instead in order to determine what resistance does the gauge want to see . I measured the limits of the gauge: approx. 10 ohms for the full tank and 340 ohms for the empty tank. So my question is why does the gauge have wrong limits?

 

[mkov608]

What fault codes are stored in ECU memory?

 

[getman]

I dont know how I can read the fault codes

 

[Digdog]

If you have an 'active' fault code put the key in but don't start it and press Mode till it says Fault Code then press 'set' it will display the code if it is active. Sensors are easy to change, do it outside because gas spills everywhere. Have a fire extinguisher handy

 

[getman]

the sensor was recently replaced. It's new and original spare part, fits to 2005 RXP215. I'm sure, that the resistance range of 0 - 90 ohms is correct. The problem is, that the gauge shows the empty tank only at 340 ohms and not at 90 ohms !!! Could it be damaged MPEM?

 

[Digdog]

Manual says .14vdc for full reading and 2.7vdc for empty reading using testing harness in the machine, there is also an ohms reading if you can read this page

 

[ski-d00]

Your ECU is the problem. I've seen this several times and the only fix was a new ECU. Check to make sure your resistance from the fuel tank sensor is correct between 0 and 90 ohms using a multimeter but most likely it is fine. The ECU is not.

 

[getman]

It does not matter if the sensor is working or not. I simulated the sensor with a connected potentiometer. The gauge shows the empty tank at 340 ohms. That's the problem. And I do not know why the resistance range is wrong. And yes I measured tank sensor resistance - it's correct - between 0 and 90 ohms.

Are you sure the ECU is the problem? Maybe the MPEM? The sensor is directly connected to MPEM, and the information center is directly connected to the MPEM.

 

[ski-d00]

Yes, it would be the MPEM. Last one I fixed was a 2007 so no MPEM but the one before that was an 05 and put a used MPEM in to fix it.

 

[Digdog]

It does not matter if the sensor is working or not. I simulated the sensor with a connected potentiometer. The gauge shows the empty tank at 340 ohms. That's the problem. And I do not know why the resistance range is wrong. And yes I measured tank sensor resistance - it's correct - between 0 and 90 ohms.

Are you sure the ECU is the problem? Maybe the MPEM? The sensor is directly connected to MPEM, and the information center is directly connected to the MPEM.

Did you look for the fault code?

 

[getman]

I don't have mode and set buttons, only vts and start

 

[ski-d00]

No mode and set buttons on a 2005 Rxp? Are you sure it's a 2005? Last 2 digits of hin will tell year. 2006 was the first year they did away with the buttons but they also eliminated the Mpem so I'm guessing you have a 2006 and you need a new ECU.

 

[getman]

I'm sure, that I have a MPEM. This is a black box with fuses and two connectors. Yes, there are no mode and set buttons. The information center is digital without arrows. Motor and ECM are from 2005.

 

[ski-d00]

So do you have the old style gauge...



Or, the new style...



You're saying you have the new style? I've never seen a 2005 with the new style. Your motor and ECM may have been made in 2005 but it sure sounds like a 2006 model ski. Have any pics?

2006 was a mid year conversion on several items. It still could have had an MPEM even with the new gauge.

 

[getman]

I have the new style gauge. I will take some pics later

 

[ski-d00]

Don't really need pics, just look at the last two digits of the HIN at the back. That will be the year.

 

[greenhornet2]

unless you hooked the potentiometer up to the gauge directly it could be the wiring no?

 

[getman]

The last two digits of the HIN are 05. I connected the potentiometer instead of the fuel sensor, not directly to the gauge. There is no wiring fault.