P0546: Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 1)

P0546 is a emissions-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0546 and illuminates the check engine light.

If your vehicle has triggered P0546, you may notice one or more of these symptoms:

• Check engine light on
• Often no change in how the car drives at first
• Glow plug light flashing on some diesels, VW group TDIs among them
• Reduced power or limp mode on some models
• Particulate filter regeneration not taking place, so a DPF warning can follow later
• P0544 or P0545 (other faults on the same sensor) stored alongside on some cars

Here are the most common causes of P0546:

Generally yes, for short-term driving. Driveable in the short term, and the car often feels normal at first. Do not leave it for weeks: without a trustworthy temperature signal from the first exhaust sensor, the engine computer may limit power to protect the turbo and may suspend particulate filter regeneration. A filter that goes too long without regenerating can block, which turns a sensor or wiring repair into a DPF clean or replacement.

Follow these steps to pinpoint the root cause of P0546:

1. Read all stored codes and the freeze frame with an OBD2 reader. Note any other codes for the same sensor (P0544 or P0545) and any particulate filter codes such as P2463 or P244B. A generic OBD2 reader shows the codes, the freeze frame and standard live data, and a few engines report exhaust gas temperature on a standard PID. On most cars the individual sensor readings, the soot load and the regeneration status need manufacturer-level software, and only that software or a workshop can run a forced regeneration.
2. Find out which physical sensor is number 1 on your engine. On many diesels it sits in the exhaust manifold just before the turbo, but engines with several exhaust temperature sensors number them differently, so check the workshop information before buying a part.
3. Check that the sensor connector is plugged in and latched, especially if the exhaust, turbo or heat shields have been worked on recently. Then unplug it and inspect for water, corrosion and pushed-back pins.
4. Measure the sensor's resistance against the manufacturer's specification. No continuity at all means the sensor or its lead has gone open.
5. Check the signal and ground wires for continuity back to the engine computer, and with the ignition on check that the signal wire is not carrying battery voltage.
6. Replace the sensor if it is out of specification, using the correct part for the engine code and position. A sensor that has been in the exhaust for years is often seized, so penetrating oil and heat may be needed, and a buried sensor 1 can mean removing heat shields.
7. Clear the code and road-test. If the filter loaded up while the sensor was faulty and the car does not regenerate on its own, a forced regeneration with manufacturer-level software may be needed.

Repair costs for P0546 vary depending on the root cause and your vehicle. Here are typical estimates:

P0546 behaves differently depending on your vehicle. Select your car below for model-specific causes and known issues:

These codes are often seen alongside P0546 or indicate related issues: