---
title: "Fuel Level Sensor"
industry: "Motor Vehicle Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:FUEL_LEVEL_SENSOR"
  data_integrity_hash: "9ee85ee48c869d96bc35dad36fa0222a"
  source_authority: "https://cnfx.com"
  strict_mode: true
source_identity:
  provider: "CNFX Industrial Knowledge Graph"
  index_version: "2026.Q1-Universal"
  authority_id: "URN:CNFX:ME:FUEL_LEVEL_SENSOR"
  data_source_uri: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/fuel-level-sensor.md"
  official_resource_url: "https://cnfx.com/industry/motor-vehicle-manufacturing/product/fuel-level-sensor"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "0-100% fuel level with ±1.5% accuracy at 25°C, 0.5-4.5V analog output corresponding to 0-100% level"
    unit: "Ω"
engineering_limits:
  max_safe_operating_point:
    value: 0.25
    unit: "V"
    consequence: "Potentiometer wiper wear exceeding 0.1mm depth causing contact resistance &gt;100Ω, or float mechanism binding due to ethanol fuel phase separation creating gum deposits &gt;0.5mm thickness"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Ethanol-blended fuel phase separation creating conductive sludge with resistivity &lt;10kΩ·cm"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Install hydrophobic polymer coating (PTFE) on float arm with 50μm thickness minimum"
  - node_2:
      trigger: "Repeated thermal cycling from -40°C to 85°C at &gt;5°C/min rate"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Implement glass-fiber reinforced PPS housing with CTE 3.2×10^-5/°C matching ceramic substrate"
bom_nodes:
  float-arm:
    type: "component"
    urn: "URN:CNFX:ME:FLOAT_ARM"
    interface_type: "physical-logic-coupled"
  potentiometervariable-resistor:
    type: "component"
    urn: "URN:CNFX:ME:POTENTIOMETERVARIABLE_RESISTOR"
    interface_type: "physical-logic-coupled"
  housing:
    type: "component"
    urn: "URN:CNFX:ME:HOUSING"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 14229-1:2020 (ROAD VEHICLES - UNIFIED DIAGNOSTIC SERVICES)"
    scope: "Verified Engineering Specification"
  - standard: "ANSI/SAE J1939-71:2021 (VEHICLE APPLICATION LAYER)"
    scope: "Verified Engineering Specification"
  - standard: "DIN 70000:2019 (AUTOMOTIVE ENGINEERING - FUEL LEVEL SENSORS)"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/motor-vehicle-manufacturing/product/fuel-level-sensor.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "27d45263677765696a2d407484baf7a99dee68592048e6b9ca454b396ace54b5"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Fuel Level Sensor

## 1. Technical Definition
A sensor that measures and monitors the amount of fuel remaining in a fuel tank.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **0-100% fuel level with ±1.5% accuracy at 25°C, 0.5-4.5V analog output corresponding to 0-100% level**. Failure boundary: **Output voltage deviation beyond ±0.25V from calibrated linear curve, or response time exceeding 500ms for 90% step change**, Mechanism: **Potentiometer wiper wear exceeding 0.1mm depth causing contact resistance &gt;100Ω, or float mechanism binding due to ethanol fuel phase separation creating gum deposits &gt;0.5mm thickness**.

### 2.1 Analytical Physics Model
Governed by the **Combined Measurement Uncertainty**:

> **Primary Equation**: $u_c = \sqrt{\sum u_i^2}$  
> **Engineering Impact**: Defines the precision confidence interval for inspection.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| u_i | Standard Uncertainty components | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Ethanol-blended fuel phase separation creating conductive sludge with resistivity &lt;10kΩ·cm | 8 | Short circuit between wiper and resistive track causing output stuck at 4.5V | Install hydrophobic polymer coating (PTFE) on float arm with 50μm thickness minimum |
| Repeated thermal cycling from -40°C to 85°C at &gt;5°C/min rate | 8 | Potentiometer track delamination causing open circuit (output 0V) | Implement glass-fiber reinforced PPS housing with CTE 3.2×10^-5/°C matching ceramic substrate |

## 3. Key Technical Parameters
| Parameter | Value | Unit | Status |
| :--- | :--- | :--- | :--- |
| spec | Config-dependent | Ω | Verified |

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Fuel Tank Assembly Line**, **Automated Calibration System**, **Environmental Test Chamber**  
**Downstream Applications**: Automotive Fuel Gauge, Vehicle Telematics System, Fleet Management Dashboard  

## 5. Engineering Risks & FAQ
- **Caution**: 
- **Caution**: 
- **Caution**: 

### Q: What materials are used in this fuel level sensor construction?
**A**: This sensor features a durable plastic housing, corrosion-resistant stainless steel float arm, and reliable copper electrical contacts for optimal performance in motor vehicle applications.

### Q: How does this fuel level sensor work in motor vehicles?
**A**: The sensor uses a float arm that moves with fuel levels, connected to a potentiometer that varies electrical resistance. This signal is sent to your vehicle's fuel gauge for accurate fuel level monitoring.

### Q: What components are included in the fuel level sensor BOM?
**A**: The bill of materials includes the stainless steel float arm, potentiometer/variable resistor for signal generation, and protective plastic housing that contains all components.

## 6. Manufacturing Compliance
- ISO 14229-1:2020 (ROAD VEHICLES - UNIFIED DIAGNOSTIC SERVICES)
- ANSI/SAE J1939-71:2021 (VEHICLE APPLICATION LAYER)
- DIN 70000:2019 (AUTOMOTIVE ENGINEERING - FUEL LEVEL SENSORS)

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Fuel Level Sensor](https://cnfx.com/industry/motor-vehicle-manufacturing/product/fuel-level-sensor)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **3** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: FUEL_LEVEL_SENSOR | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: 800b592d
