PEX Aftermarket Level Sensors

Purpose and Function:

Level sensors monitor the quantity of fluids in tanks or reservoirs and provide feedback to the vehicle ECU, instrument panel, or control modules. In heavy-duty vehicles, they are used for:

Fuel level monitoring for accurate fuel gauge readings and fuel management systems.
DEF/urea tank monitoring for SCR dosing and emissions compliance.
Engine oil, coolant, and hydraulic fluid monitoring for maintenance and system protection.
Other applications: AdBlue, hydraulic reservoirs, coolant expansion tanks, and PTO fluid levels.
Accurate level sensing ensures vehicle safety, emissions compliance, and operational efficiency.

Features & benefits

Real-time fluid monitoring to prevent engine or system damage.
Supports emissions compliance by ensuring DEF/urea availability for SCR systems.
Reduces downtime and maintenance costs through early warning alerts.
Rugged design suitable for vibration, temperature extremes, and chemical exposure.
Can be integrated into tank assemblies for easy installation and maintenance.

Technical Highlights

Sensor types:
- Resistive (float-based): Resistance changes with float position; used in fuel tanks and oil reservoirs.
- Capacitive: Measures fluid level by capacitance changes; often used for corrosive or harsh fluids (DEF/urea).
- Ultrasonic or optical: Non-contact sensors for precise level measurement in critical tanks.
- Magnetic or reed switch sensors: Float triggers magnetic switch; simple and reliable for many heavy-duty applications.
Placement: Installed inside or on top of tanks/reservoirs; may include a probe or integrated float.
Output signal: Analog voltage, resistance, or digital pulse; some CAN-enabled sensors report level directly to the ECU.

Diagnostic and Testing Tips

Visual inspection: Check sensor body, float, wiring, and connectors for damage, corrosion, or buildup.
Resistance or voltage test: For float/resistive sensors, measure signal across full range; confirm smooth change without jumps.
Digital/capacitive sensors: Monitor output with scan tool; verify accurate reading against actual fluid level.
Functional check: Add or remove fluid to observe real-time changes in sensor output or dashboard gauge.
Replace sensors with erratic readings, open/short circuits, or mechanical float failure; also inspect wiring harnesses and connectors.

Installation Tips and Common Issues

Ensure proper sensor orientation and full immersion of floats or probes where required.
Route wiring away from heat, vibration, and sharp edges; secure connectors with locking clips.
Avoid contamination with dirt, debris, or incompatible fluids that can impair sensor operation.
For capacitive or ultrasonic sensors, ensure tank walls and fluid properties match OEM calibration requirements.
Periodically inspect floats, mechanical linkages, and wiring, as mechanical wear or buildup can lead to false readings.