Gas level gauge displays wrong level of fuel?

If the gas gauge of your 2007 Dodge Nitro R/T always shows a full reading, there could be a few possible causes for this issue:

1. Faulty fuel level sensor: The fuel level sensor is responsible for measuring the amount of fuel in the tank and sending that information to the gauge on the dashboard. If the sensor is malfunctioning or stuck in the "full" position, it will consistently display a full reading on the gas gauge.
2. Wiring or electrical issue: There might be a problem with the wiring or electrical connections between the fuel level sensor and the gauge. If there is a loose or damaged wire, it could prevent the accurate transmission of fuel level data to the gauge.
3. Instrument cluster malfunction: The problem could be with the instrument cluster itself, where the gas gauge is located. If there is a fault in the cluster's circuitry or display, it may cause the gauge to always show a full reading.
4. Gauge calibration issue: In some cases, the gas gauge might be improperly calibrated, resulting in it always displaying a full tank. Recalibrating the gauge might resolve the issue.

To address this problem, it is recommended to take the vehicle to a qualified mechanic or an authorized Dodge service center. They will have the necessary diagnostic tools and expertise to identify the exact cause of the issue and perform the required repairs. They may need to inspect the fuel level sensor, check the wiring connections, or evaluate the instrument cluster to resolve the problem.

Then it sounds like the gauge is wrong. The float for the gas tank could be sticking at that point, or there could be an electrical issue causing the signal to the gauge to be off. I would think fuel level sending unit, unless you can verify there is in fact gas in the tank when the car shuts off. If that is the case, then it may be an issue with the gas pump suction getting air at that level and not being able to pump that last bit.

Did you test before replacing ? Do you know how it work's ?

Fuel Level
The body control module (PZM) monitors the fuel level sender input in order to determine the current fuel level. The PZM filters the input and sends a message via the Class 2 serial data line. The IPC receives this message and displays the current fuel level. The fuel level is sent from the PZM to the IPC at changes of 0.5 L (0.02 gal) or on the request of the IPC, with a resolution of 0.04 L (0.01 gal).
• For the digital IPC, when the fuel level is above 18.5 gal, the IPC displays an F. For readings between 18.5-2.5 gal, whole gallon/liter numbers are displayed. When the fuel level reaches 3.0 gal the message FUEL LEVEL LOW is displayed on the driver message center. When the fuel level reaches 2.5 gal, the IPC displays an E. When the fuel level is 1.2 gal or below the IPC displays a flashing E.
• For the analog IPC, when the fuel level is above 18.5 gal, the fuel gauge pointer is on F. When the fuel level is below 2.5 gal the fuel gauge pointer moves to E. When the fuel level is below 3.0 gal the IPC displays a FUEL LEVEL LOW message.
If the updates are not received or a communication error is detected, the IPC performs the following actions:
• For the digital IPC, the fuel gauge is dashed.
• For the analog IPC, the fuel gauge pointer moves to E.

Fuel Gage Inaccurate or Inoperative
Circuit Description
The IPC monitors the fuel level sent by the PZM through the class 2 serial data line. The IPC software controls one of the following two gauge types:
• A digital gauge consisting if a two-digit numeric seven-segment display
• An analog gauge consisting of a needle pointer.
The IPC interpolates and scales the fuel level information that the IPC receives from the PZM.
When you operate the vehicle in diagnostic mode, either in the vehicle diagnostic system or with a scan tool connected, the fuel signal supplied to the IPC is not filtered by the PZM. The unfiltered fuel signal causes the IPC to show real time readings and may be mistaken as an erratic fuel level display.
Diagnostic Aids
Connect a scan tool to the DLC.

It's not a fuse problem , fuel sending unit in side the fuel tank is bad or the gauge itself is . Your best bet , have it diagnosed by a qualified repair shop .
The fuel level sending unit in the gas tank is a input to the PCM - engine computer . The PCM shares this fuel level info to the instrument cluster over the class 2 serial data network . If a fuse was bad the whole instrument cluster would be out .

Fuel Gage
The instrument panel cluster (IPC) displays the fuel level as determined by the powertrain control module (PCM). The IPC receives a class 2 message from the PCM indicating the fuel level volume. The fuel gage defaults to E (empty) if:
• The PCM detects a malfunction in the fuel level sensor circuit.
• The IPC detects a loss of class 2 communications with the PCM.
When the fuel level is less than 14 percent, the low fuel indicator illuminates.

At the dealer we would hook up the factory scan tool to see if the info from the PCM is getting to the instrument cluster . How to test fuel gauge tank sending unit P0463 GM

It's not the ground wire , the gauge grounds inside the instrument cluster .Your sending unit or the gauge it's self is bad .
Body Control System Operation
The Body Control Module (BCM) performs the following functions:
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Gauge control

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Instrument cluster indicator control

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Fuel gauge control

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Temperature gauge control

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Theft deterrent

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A/C compressor request

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A/C cooling fan

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Exterior and interior lighting control for the following lamps:

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Daytime Running Lights (DRL)

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Automatic lighting control

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Fog lamps

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Interior lighting

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Battery rundown

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Chime

Gauge Control
The Body Control Module (BCM) receives Class 2 serial data messages from the Powertrain Control Module (PCM) to determine the following gauge information:
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Engine coolant temperature

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Fuel level sensing

Your best bet is to take your vehicle to a qualified repair shop !
Fuel Gage Inaccurate or Inoperative

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Select the PCM display DTCs function on the scan tool.

Does the scan tool display any DTCs?
--
YES - Go to Diagnostic Trouble Code (DTC) List (2.4L) or Diagnostic Trouble Code (DTC) List (3.4L) in Engine Controls
NO - Go to Step 3

3

With the scan tool, select Instrument Panel Cluster, Special Functions and command the fuel gauge UP.
Does the fuel gauge complete a full sweep when commanded?
--
YES - Go to Step 4
NO - Go to Step 12

1. Turn OFF the ignition.
2. Disconnect the fuel level sender.
3. Connect the J 33431-C Signal Generator and Instrument Panel Tester between the signal circuit of the fuel level sender and the ground circuit of the fuel level sender.
4. Turn ON the ignition, with the engine OFF.
Important: Verify the J 33431-C resistance setting with a DMM.

5. Set the resistance on the J 33431-C to 40 ohms.

Does the fuel gauge display at or below empty?
--
YES - Go to Step 5
NO - Go to Step 6

These are two different issues, cam sensor has noting to do with your fuel level unit.

Hi!

There is a fuse for the GAUGES, but if it was blown, nothing will work. If your Gas Gauge is acting erraticaly, the problem is most likely the Fuel Level Sending Unit, part of the Fuel Pump, unless you want to remove and replace the fuel pump, your problem will be there til then.

Note, the failure of the Sending Unit does not mean there is something wrong with the fuel pump.

Good Luck!! Don't forget to rate this post!!

Sounds like the fuel level sending unit has gone bad in the tank. Although gauges do fail, the more likely cause is tank level sensor.

It might not be anything wrong with your fuel sending unit. Keep an eye on your other gauges. I own a 2004 Pontiac Bonneville GXP. All of my gauges have started acting erratically. It started with my Temp. gauge, moved on to my speedometer, and now my oil pressure , fuel level and batty volt gauges are affected too. Its a very common problem with GM vehicles.