P2067

Code

Generic P — Powertrain

Fuel Level Sensor B Circuit Low

Brand: Generic

Type: P — Powertrain

Views: UK: 27 EN: 48 RU: 32

AI status

Completed

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Page language: EN

Causes

Short to ground in fuel level sensor B signal wire
Open or damaged wire between fuel tank sender and controller
Corroded, loose, or contaminated connector at the fuel level sender
Failed fuel level sender/module (sensor B) in tank
Poor ground or missing reference voltage to sender circuit
Water/fuel intrusion or mechanical damage to sender assembly

Symptoms

Malfunction Indicator Lamp (MIL) or service light illuminated
Fuel gauge reads empty or erratic on instrument cluster (sensor B affected)
Possible fuel level warning lamp or incorrect range estimation
Intermittent or no fuel level data available to BCM/ECU systems that use secondary sensor
Related drivability systems may show warnings if they rely on accurate tank level data

What to check

Scan for stored codes and freeze-frame data; note any related fuel or instrument cluster codes
Visually inspect wiring and connectors at top of fuel tank/sender for corrosion, damage or loose terminals
With key ON (engine OFF) back-probe sender connector: check for reference voltage (typically ~5 V) and ground presence
Measure signal voltage at sender connector while moving float or using hand-operated lever; observe for voltage change
Check continuity between sensor signal pin and PCM/BCM input; check for short to ground (low resistance) or short to battery (+)
Measure resistance of sender (if accessible) while moving float to confirm variable resistance behavior

Signal parameters

Typical architecture: single-ended analog or resistive sender; signal range 0–5 V (varies by manufacturer)
Normal mid-level reading usually around ~2–3 V (vehicle-dependent)
Low/fault threshold: signal near 0.0–0.5 V or below expected minimum triggers 'low circuit' DTC
Resistance-type sender: resistance changes smoothly as float moves; abrupt zero or near-zero reading indicates short or failed element

Diagnostic algorithm

Retrieve stored codes, freeze-frame and live fuel level data for both A and B sensors; note conditions when fault set.
Perform visual inspection of connectors, wiring harness, and tank top cover. Repair any obvious damage or corrosion.
With key ON (engine OFF) back-probe at sender connector: verify reference voltage (usually ~5 V) and good ground. If reference or ground missing, trace upstream to fuse/PCM/ground point.
Measure signal voltage at connector while moving the sender float. If voltage stays very low (near 0 V) with float movement, suspect short to ground or failed sender.
Check continuity/resistance from sender signal pin to PCM/BCM input. If open or high resistance, repair open circuit. If near 0 ohms to ground, locate and repair short to ground.
If wiring and connectors are good, bench-test or replace the fuel level sender/module. Reinstall and re-test.
If replacement sender does not correct issue, verify PCM/BCM input circuit functionality and repair or replace controller only if confirmed faulty.
Clear codes and perform functional test/drive cycle to confirm repair. Monitor live data for consistency.

Likely causes

Damaged wiring harness rubbing on chassis causing insulation wear and short to ground
Connector pins pushed back, corroded, or contaminated with fuel
Sender float stuck at bottom or mechanical linkage failed
Sender internal resistance element failed (shorted)
Failed ground at tank or module mounting

Fault status

⚠️ Status

Low voltage detected on Fuel Level Sensor B circuit — signal below expected threshold (possible short to ground, open circuit, connector/wiring or sender failure).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours