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

The exhaust gas temperature sensor is a thermistor in a voltage divider with the module's pull-up resistor; the first one (sensor 1) sits before the turbocharger, the oxidation catalyst or after it depending on the maker. Diesels use it for particulate filter regeneration and component protection; CARB names it explicitly as a monitored input. P0546 means the signal is above range: GM L5P above 922 Ω, GM LML above 2.21 V, Ford 6.7 L above 2.66 V for about 2 s, Saab 9-5 2.0 TiD above 4.9 V for 1 s. Most often an open circuit pulled up to the reference, otherwise a short to positive; live data then show −40 °C or the maximum. The module uses a substitute value and blocks filter regeneration.

Medium severity. Can I keep driving?If the light is on steadily, take a highway drive or go to a repair shop soon. If the car is in limp mode or the light is flashing, do not push the engine.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.

Symptoms

Check engine light on
Particulate filter regeneration missing, filter warning
Possible power reduction

Most likely causes

Sensor element or internal lead open (vibration, heat)
Connector loose or corroded, broken wire
Signal line shorted to positive
Engine module

What to check, in order

Start with the simplest. You can tick off each step.

Read the soot load and differential pressure with a scanner
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Check the differential pressure sensor's hoses
Check the temperatures before and after the filter
Fix any fuel injection or EGR codes before regenerating
Perform a regeneration while driving or at a repair shop when the diagnosis allows it

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P0546 means

P: Powertrain: engine and transmission
0: Generic code: same on every make
5: Speed and idle
46: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0546?

If the light is on steadily, take a highway drive or go to a repair shop soon. If the car is in limp mode or the light is flashing, do not push the engine.

What causes code P0546?

The most common causes are: sensor element or internal lead open (vibration, heat); connector loose or corroded, broken wire; signal line shorted to positive.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.