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P codepowertrainMedium severity

P0547Exhaust Gas Temperature Sensor Circuit (Bank 2, Sensor 1)

A general fault has been detected in the exhaust gas temperature sensor 1 circuit on Bank 2.

Definition

The PCM continuously monitors the Bank 2, Sensor 1 exhaust gas temperature sensor circuit for opens, shorts, and readings that do not correlate with engine operating conditions. P0547 sets when the signal is erratic, out of the expected range, or fails a rationality comparison against the Bank 1 sensor or modeled exhaust temperature. The MIL illuminates, and on diesel applications the PCM may inhibit DPF regeneration or limit boost and fueling because it cannot confirm safe exhaust temperatures, which can lead to soot overloading and reduced power. Bank 2 is the cylinder bank opposite the one containing cylinder 1.

Common causes

  • Failed or drifting EGT sensor on Bank 2
  • Damaged, chafed, or heat-hardened wiring in the sensor harness
  • Corroded or loose connector terminals near the exhaust
  • Intermittent open or short from vibration
  • Exhaust leak upstream of the sensor skewing readings
  • Faulty PCM input circuit (rare)

Common misdiagnoses

  • Both bank sensors replaced when only Bank 2 wiring is at fault
  • Diesel particulate filter replaced for regeneration faults caused by the sensor
  • Catalytic converter replaced on the assumption of overheating
  • Turbocharger replaced for reduced-power symptoms

Troubleshooting steps

  1. 1.Compare Bank 1 and Bank 2 EGT PIDs

    At idle and steady cruise both banks should read within roughly 50 C of each other; a Bank 2 value that is pegged, frozen, or wildly different isolates the fault.

  2. 2.Inspect the Bank 2 sensor harness and connector

    Trace the wiring from the sensor boss to the connector looking for heat damage, chafing on the exhaust, and corroded terminals.

  3. 3.Test sensor resistance and compare to spec

    Measure the sensor's resistance cold and again warm; compare against the published temperature/resistance table, and replace the sensor if it is open or out of range.

  4. 4.Wiggle-test the circuit while monitoring live data

    Flex the harness and tap the connector while watching the EGT PID; any dropout confirms an intermittent connection.

  5. 5.Check for exhaust leaks near the sensor

    Inspect the manifold and turbo joints on Bank 2 for leaks that admit ambient air and cool the sensor tip abnormally.

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