P0545

Universal

Exhaust Gas Temperature Sensor Circuit Low - Bank 2 Sensor 1

Definition source: General OBD-II reference catalog
Definition verification: Not independently verified for display.
Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium
Medium Severity

An exhaust gas temperature sensor measures exhaust heat so the vehicle’s control system can monitor engine and emissions-system conditions. This code means the circuit for Bank 2 Sensor 1 is reporting a low electrical signal; it does not by itself prove the exhaust is actually too cool or that the sensor needs replacement. Depending on the vehicle, the fault may affect emissions control or protective strategies.

Report an error with this code

⚠️ Before You Begin (Safety First)

If the vehicle is overheating, has severe power loss, produces smoke, or displays a critical warning, stop safely and arrange professional help. Exhaust parts can remain hot after shutdown; let them cool before inspection. Avoid touching the exhaust or working near moving parts.

Common Symptoms

  • The check-engine light may be on.
  • There may be no noticeable change in how the vehicle drives.
  • Depending on the vehicle’s control strategy, emissions-system monitoring or protective operation may be affected.
  • If the fault disrupts related control strategies, the vehicle may limit performance or show other warnings; these effects are not specific to this code.

Common Causes

  • A failed exhaust gas temperature sensor may produce a low circuit signal.
  • Wiring may be damaged, melted by exhaust heat, chafed, or shorted to ground.
  • A loose, corroded, or damaged connector may interfere with the signal.
  • A fault in the circuit’s power, ground, or control-module side may cause the low reading.
  • The code may be intermittent, so the fault may not be present during every inspection.

Diagnostic Steps

  1. Record the code and any related codes before clearing anything; related faults can help identify whether the issue involves one sensor or a wider circuit problem.
  2. Park safely, switch off the engine, and let the exhaust cool fully before inspecting it.
  3. Visually check accessible Bank 2 Sensor 1 wiring and its connector for looseness, corrosion, abrasion, or heat damage; do not pull on the wires.
  4. If the connector is accessible, check that it is seated and free of obvious contamination, following vehicle-specific service guidance.
  5. If the code returns or wiring damage is not obvious, have the circuit tested using the correct wiring diagram and vehicle-specific procedures rather than replacing the sensor by guesswork.

When to Call a Professional

Confirm the code and review available scan data for Bank 2 Sensor 1. With the exhaust cool, inspect the sensor connector and nearby wiring for heat damage, corrosion, loose connections, or contact with exhaust parts. Use the vehicle-specific wiring diagram and service information to test the circuit and distinguish a sensor fault from a wiring or control-module issue. Do not replace a part based on the code alone.

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Commonly Asked Questions

Does P0545 prove the exhaust gas temperature sensor is bad?

No. It identifies a low electrical signal in the Bank 2 Sensor 1 circuit. The sensor, connector, wiring, or another part of the circuit could be responsible.

Does “circuit low” mean the exhaust temperature is too low?

Not necessarily. The code describes the electrical signal detected by the control system, not a confirmed measurement of actual exhaust temperature.

Can I keep driving with P0545?

If the vehicle runs normally and has no critical warnings, a cautious trip for diagnosis may be reasonable. Stop if it overheats, loses substantial power, smokes, or displays a critical warning.

What does Bank 2 Sensor 1 identify?

It specifies the sensor position named by the code. The exact location and sensor layout depend on the vehicle’s engine and exhaust system, so use model-specific service information.

What should be checked before replacing a sensor?

Inspect the connector and wiring for damage or poor connection, then test the circuit and review scan data using vehicle-specific information. A low signal can result from wiring or circuit faults as well as a failed sensor.

Browse Available Code Guides

Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.