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P0642 — Sensor Reference Voltage A Circuit Low

5V sensor reference voltage is below specification.

Severity: HighRepair: $50-$1,000Difficulty: Advanced

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Common symptoms of P0642

Common causes of P0642

Repair cost & difficulty

Typical cost to fix P0642: $50-$1,000 · Difficulty: Advanced

Pro tip: Unplug sensors one at a time. When reference voltage returns to 5V, you've found the shorted sensor.

Vehicles commonly affected

All makes

Related trouble codes

P0641P0643

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ScanFixAI is a diagnostic aid, not a substitute for professional repair. Cost estimates are typical ranges and vary by vehicle and region.