P0549: Exhaust Gas Temperature Sensor Circuit High Bank 2 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. Bank 2 sensor 1 exists only on V engines with a separate exhaust path per cylinder bank. No manufacturer document available to us uses this code; the thresholds known for bank 1 apply by analogy. P0549 means the signal is above range, usually an open circuit or a short to positive – for bank 1 GM uses above 922 Ω, Ford above 2.66 V.

Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.

Symptoms

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

Most likely causes

• Sensor or internal lead open
• Connector loose, broken wire
• Short to positive
• Engine module

What to check, in order

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

1. Read the soot load and differential pressure with a scanner
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Check the differential pressure sensor's hoses
4. Check the temperatures before and after the filter
5. Fix any fuel injection or EGR codes before regenerating
6. 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 P0549 means

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

Frequently asked questions

Can I keep driving with code P0549?

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 P0549?

The most common causes are: sensor or internal lead open; connector loose, broken wire; short to positive.

Related codes

• P0547Exhaust Gas Temperature Sensor Circuit Bank 2 Sensor 1
• P0548Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 1
• P0546Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 1
• P2036Exhaust Gas Temperature Sensor Circuit High (Bank 2 Sensor 2)

Sources

• hella.com: checking the exhaust gas temperature sensor
• gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
• fordservicecontent.com: obd summary diesel 2023
• law.cornell.edu: 13 CCR 1968.2

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.