Failed fuel level sensor or sending unit inside the fuel tank; Damaged, corroded, or disconnected wiring between the fuel level sensor and its control module; Poor electrical connection at the fuel pump module harness connector; Failed fuel pump control module or interface module that relays sensor data onto the CAN bus; Corrosion or water intrusion at a CAN bus splice or connector shared with the fuel level circuit; Software or calibration fault in the module that publishes fuel level data; Low battery voltage or a weak ground causing intermittent communication dropout

DTC codes / U06xx · Network communication / U0676

U0676Lost Communication With Fuel Level Sensor A

Q: What does code U0676 mean?

Lost Communication With Fuel Level Sensor A. U0676 is a generic network communication code indicating that a control module on the vehicle's Controller Area Network (CAN) bus has lost contact with the fuel level sensor designated as 'A'. The module that monitors fuel level (often the body control module or instrument cluster) has stopped receiving valid data messages from that sensor or its interface, so the fuel gauge may default or the driver information center may show a fault.

U0676 is a generic network communication code indicating that a control module on the vehicle's Controller Area Network (CAN) bus has lost contact with the fuel level sensor designated as 'A'. The module that monitors fuel level (often the body control module or instrument cluster) has stopped receiving valid data messages from that sensor or its interface, so the fuel gauge may default or the driver information center may show a fault.

SystemNetwork

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaNetwork communication

Symptoms you may notice

Fuel gauge reads empty, full, or fluctuates erratically regardless of actual fuel level
Low fuel warning light illuminates or flashes when the tank is not empty
Driver information center displays a message such as 'fuel level sensor fault' or dashes instead of a distance-to-empty value
Often no symptoms besides the warning light, especially if the gauge happens to default to a plausible reading
Remote start or fuel-related convenience features may be disabled as a failsafe
Other unrelated warning lights may appear if the same CAN bus segment is affected

Common causes, most likely first

Failed fuel level sensor or sending unit inside the fuel tank
Damaged, corroded, or disconnected wiring between the fuel level sensor and its control module
Poor electrical connection at the fuel pump module harness connector
Failed fuel pump control module or interface module that relays sensor data onto the CAN bus
Corrosion or water intrusion at a CAN bus splice or connector shared with the fuel level circuit
Software or calibration fault in the module that publishes fuel level data
Low battery voltage or a weak ground causing intermittent communication dropout

How to diagnose and fix it

Verify battery voltage and charging system output, then clear the code and test-drive to see if U0676 returns
Inspect the fuel pump module harness connector and nearby wiring for corrosion, chafing, or loose pins
Measure resistance across the fuel level sensor while moving the float through its range and compare to the manufacturer's specification
Check for continuity and short-to-ground on the sensor signal and return circuits between the sensor and the module that reports fuel level
Use a scan tool to read live fuel level data and confirm whether the module sees a plausible signal or a fixed default value
If the sensor signal is good at the module but the CAN message is missing, diagnose the module that publishes fuel level data and its network wiring
Replace the faulty fuel level sensor, pump module assembly, or control module only after electrical and network tests confirm the failure

Why the fuel gauge lies before the code sets

Many vehicles filter and average fuel level data over several minutes, so a failing sensor can produce a normal-looking gauge for a while before U0676 finally stores.
A fuel level sensor that reads open circuit can cause the gauge to default to empty and trigger a low fuel warning even when the tank is full, leading owners to replace a good fuel pump.
Corrosion at the fuel pump module connector is a frequent cause on vehicles driven in wet or salty conditions, and the connector often looks fine until it is separated and inspected.
U0676 can be set by a module that simply stops transmitting fuel level data because of an internal fault, so replacing the sensor without checking the publishing module wastes money.
A weak battery or poor ground can cause intermittent CAN communication loss that mimics a failed sensor, so always check voltage and grounds before condemning parts.

Can I keep driving with U0676?

The vehicle remains safe to drive because fuel level is not a safety-critical system, but you should refuel based on mileage rather than the gauge until the fault is repaired. Avoid long trips into remote areas where an inaccurate gauge could leave you stranded.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.