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C. Walker, Jr.
C. Walker, Jr., Auto Mechanic
Category: Car
Satisfied Customers: 710
Experience:  Shop training and experience.
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I have a 2000 Isuzu Rodeo I just bought. The fuel gauge is

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I have a 2000 Isuzu Rodeo I just bought. The fuel gauge is not reading correctly. When full, it seems Ok. When the gas gets to about 3/4, it reads less than is actually in the tank. At about 1/2, it reads almost empty. I heard this is a common problem for this vehicle, I would just like to know what it is so I can fix it. There are no error codes related to this problem.

Any ideas,
Mark C
The problem is most likely the fuel level sender is acting up. You can test the fuel level sensor. It is inside the fuel tank and is apart of the fuel pump assembly. To test it follow these steps.

Test for 5 volts on the Orange/Green wire at the Fuel Level Sensor with the fuel level sensor unplugged and key on. With the fuel level sensor plugged in and backprobing with the key on, the voltage will drop down in voltage, depending on the fuel level in the tank (fuel level sensor float position). The Blue/Yellow wire is the ground wire for the Fuel level sensor. Ohm the fuel level sensor and look for 80 ohms with the float held up to indicate a full tank and 290 ohms with the float all the way down, indicating an empty tank.

You will find the fuel level sensor is bad by doing the above test. You will need to replace it in order to correct the problem. This is a very common problem on the vehicle.

Let me know if you have any other questions. I have included the steps to gain access to the sender which is dropping the fuel tank as if you are replacing the fuel pump. Thanks.

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