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P0428

PowertrainCatalystmoderate severity

Catalyst Temperature Sensor High Input (Bank 1, Sensor 1)

What P0428 Means

The PCM detected an abnormally high signal from the bank 1 catalyst temperature sensor. This may indicate a short to voltage or a failed sensor.

Symptoms

  • Check engine light on
  • Failed emissions test
  • High temperature reading

Common Causes

  • Faulty temperature sensor
  • Short to voltage in wiring
  • Open ground circuit
  • Poor connector contact

Diagnostic Steps

  1. Scan and confirm P0428
  2. Check sensor signal voltage
  3. Inspect wiring for shorts to power
  4. Test sensor resistance

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Wiring Data
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Ground Points
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