1990-2000 LEXUS LS 400

4.0L V8RWDAUTOMATICgas
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B0403low severityBody

Fuel Gauge Circuit Malfunction

on 1990-2000 Lexus LS 400 4.0L V8 · RWD

What this code means

The fuel gauge is not displaying correctly or is stuck at one position.

Symptoms

  • Fuel gauge stuck on empty
  • Fuel gauge stuck on full
  • Fuel gauge reads erratically
  • Low fuel warning inaccurate

Common causes

  • Faulty fuel level sending unit
  • Instrument cluster gauge failure
  • Wiring damage between tank and cluster
  • Corroded fuel sender connector
  • Float stuck in tank

Diagnostic steps

  1. Check fuel sender resistance with scan tool
  2. Test gauge with simulated sender resistance
  3. Inspect fuel sender connector
  4. Test gauge stepper motor
  5. Check ground circuit

Repair notes

Replace fuel level sending unit in tank or instrument cluster gauge. Check sender connector for corrosion.

Other Body codes on this vehicle

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