Emissions control: EGR, DPF, catalytic converter and AdBlueGeneric OBD-II codeUrgency: Garage soon
Code P0546: exhaust temperature sensor (bank 1, sensor 1)
P0546 means: exhaust gas temperature sensor circuit, high signal (bank 1, sensor 1).[1][2][3] The engine ECU has detected that the exhaust gas temperature (EGT) sensor for bank 1, sensor 1, is giving a higher voltage than expected. This sensor sits in the exhaust, between the manifold and the catalytic converter, on the side of cylinder 1, and is a heat-sensitive resistor: the ECU measures the resulting voltage and converts it into a temperature. TaT explains that the code is set when the signal exceeds the calibrated upper threshold, which suggests an abnormally high resistance in the circuit.[1][2][3][4]
What code P0546 means
The engine ECU has detected that the exhaust gas temperature (EGT) sensor for bank 1, sensor 1, is giving a higher voltage than expected. This sensor sits in the exhaust, between the manifold and the catalytic converter, on the side of cylinder 1, and is a heat-sensitive resistor: the ECU measures the resulting voltage and converts it into a temperature. TaT explains that the code is set when the signal exceeds the calibrated upper threshold, which suggests an abnormally high resistance in the circuit.[1][2][3][4]
The ECU uses this temperature to monitor the catalytic converter and, on diesels, the particulate filter and the turbo: according to HELLA, it needs it to control the mixture or particulate filter regeneration, and according to Bosch, it protects the turbo and the catalytic converters from overheating and allows the filter to be regenerated effectively.[4][5]
The exact threshold depends on the manufacturer. In the workshop manual of a Toyota diesel, the code is triggered if the output voltage exceeds 4.95 V for 3 seconds or more, with the engine warm (coolant at 60 °C or more) and 11 minutes after starting; that manual calls "sensor 1" the one before the CCo catalytic converter and "sensor 2" the one before the particulate filter.[6]
It is a generic OBD-II code (it starts with P0), so it means the same on any brand; what changes from one engine to another is the most likely cause.[7]
Original definition (SAE J2012): Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 1[1][2][3]
Codes from the same family
They indicate the same problem in a specific cylinder, bank or sensor. Causes, symptoms and diagnosis are those on this page.
Causes of P0546 and its family
From most to least likely, according to the sources.
- 1Faulty EGT sensor, or one with an internal short circuit or a short to ground.[1][3][6]
- 2Connectors or wires in poor condition: loose or corroded terminals, broken or corroded wires.[1][3][6]
- 3An exhaust that has been modified or fitted without provision for the temperature sensor.[3]
- 4Previous damage to the sensor: HELLA mentions external impacts, power supply faults, internal wires damaged by exhaust vibration and excessive temperatures caused by injection or mixture defects.[4]
- 5Faulty engine ECU: an uncommon cause.[1][6]
Symptoms
- Engine warning light (check engine light) on in the instrument cluster.[1][3]Engine warning light: faults that cause it
- Reduced engine performance.[1][4][10]Less power: faults that cause it
- In the workshop manual of a Saab 9-2X 2.0T, also hard starting, rough idle and poor running while driving.[10]
- On a diesel with a particulate filter, the filter warning light on and more frequent or longer regenerations, according to HELLA for faults of this sensor.[4]DPF warning light: faults that cause it
- Glow plug warning light flashing, according to HELLA for faults of this sensor on a diesel.[4]Flashing glow plug light: faults that cause it
- Higher consumption, mainly because of the longer particulate filter regenerations, according to HELLA.[4]Uses more fuel: faults that cause it
- Higher polluting emissions (CO, NOx and HC), according to HELLA.[4]
How to diagnose P0546
In order: from the most likely and cheapest to check to the most expensive.
- 1Read the code with a diagnostic tool and look in the live data at the temperature the sensor reports. HELLA says that an absurd value, such as −40 °C, points to a broken wire or a failed sensor. Clear the code and do a road test to confirm that it comes back.[3][4][6]
- 2Visually inspect the sensor, its connector and the wiring: loose or corroded terminals, broken wires, damaged insulation and areas close to the exhaust heat.[1][3][4]
- 3With the sensor disconnected, check the wiring and the sensor with a multimeter following your car's manual. As examples of values: PartsAvatar gives about 150 Ω for the sensor and about 5 V at the connector; the Toyota manual asks for less than 1 Ω in the wires to the ECU and 10 kΩ or more of insulation to ground; and the Saab 9-2X manual says to look for a short to the battery if the wiring gives more than 10 V and to check the sensor's ground (less than 5 Ω).[3][6][10]
- 4Heat the sensor with a controlled heat source and check that its resistance changes as it should.[3]
- 5Only if the wiring, connector and supply are fine, replace the sensor with one of the same part number, tightened to the torque specified by the manufacturer. Replacing the ECU is the last step, once the sensor and wiring are within specification.[4][6]
Can I keep driving with P0546?
Garage soon
The sources do not give clear guidance. CarParts does not call it critical, but says that the reduced power indicates a problem that deserves prompt attention; HELLA points out that a failed EGT sensor increases emissions and consumption and can cause problems with particulate filter regenerations; and Bosch reminds us that these sensors protect the turbo and catalytic converters from overheating. PartsAvatar says nothing about whether the car can be driven. It is worth checking soon, especially on a diesel with a particulate filter.[1][3][4][5]
Documented faults related to P0546
Known faults of specific engines and cars, with their repair cost, the affected years and their sources.
Engine sensors: the most serious faults by engine and car
- High severityFrequency: Occasional2.0 DTI and 2.2 DTIVP44 injection pump and air mass meter failureGerman Wikipedia documents recurring failures of the Bosch VP44 injection pump and the air mass meter in the early years of this engine. An owner testimony for this engine describes the pump being replaced at 192,500 km, at a cost the owner calls «prohibitive».
- Medium severityFrequency: Common2.0 TDIClogged particulate filter or faulty pressure sensorThe 2.0 TDI's particulate filter clogs if the car mostly makes short journeys, because it never gets to regenerate; sometimes the fault is just the differential pressure sensor. Cleaning it costs around €200 and replacing it, €800 to €3,000.Repair (garage): €800–€3,000
- Medium severityFrequency: Common1.4 and 1.6 8vCrankshaft position sensor failure (TDC sensor)The crankshaft position sensor (capteur PMH, or TDC sensor) appears repeatedly in the reliability sources for the Clio II, the Kangoo I and the Dacia Logan I with this engine, with hard cold starting or stalling as the main symptoms. It is a cheap part, but the failure can leave you stranded.
- Medium severityFrequency: Common1.4 and 1.6 16vCrankshaft position sensor failureThe crankshaft position sensor (capteur PMH) appears repeatedly in the reliability sources for almost every generation with this engine, with hard cold starting, stalling or the car cutting out unexpectedly. It is a cheap part, but the failure can leave you stranded.
Wiring, connectors and short circuits: the most serious faults by engine and car
- Critical severityFrequency: OccasionalBMW N62 / N63Additional turbo coolant pump with a risk of short circuit and fireIn 2011 BMW recalled 5, 6 and 7 Series, X5 and X6 models built between 2007 and 2011 because of the additional turbo coolant pump: moisture, a short circuit and, in extreme cases, a fire. In 2012 there was another campaign for a crack in the pump, with a more robust version.
- High severityFrequency: Occasional1.3 TCeBlown fuel pump fuseOn the Renault Captur II and Clio V with the 1.3 TCe engine, a 20-amp fuse can blow and leave the car without an engine. According to L'argus, in April 2021 this fault still had no factory fix; the official service centre's diagnosis includes checking, and sometimes replacing, the catalytic converter.
- High severityFrequency: OccasionalM264/M254Poorly tightened 48 V earth wiring in the mild-hybrid system (fire risk)Mercedes-Benz has issued several recalls (2022-2025) because the 12 V and 48 V earth connections of some cars with a 48 V system may be poorly tightened: resistance rises, the connection heats up and a fire cannot be ruled out. The official workshop checks them and repairs them if necessary in an hour or more.
- High severityFrequency: Occasional1.9 TDIUnit injector tappet wear and injector wiring damageOn the unit injector system, the tappets that operate the injectors can wear if the oil is not changed on time, and the injector wiring can be damaged by contact with oil, causing misfires or loss of power.
- Critical severityFrequency: CommonRover 75Seat SRS connector fault with airbag and seatbelt warning light onAuto Express warns that the Rover 75's seat SRS connector can cause the airbags to fail, and dealers were fixing it with revised connectors. The Dutch APK inspection puts the airbag or seatbelt fault warning among the most frequent defects across almost all series.
- Critical severityFrequency: OccasionalAlfa Romeo GiuliettaShort circuit from badly routed wiring that can prevent gear shifting (KBA campaign, 2010-2015)Yes: according to Germany's KBA, on Alfa Romeo Giulietta cars built between 2010 and 2015 inadequate cable routing could cause a short circuit and, as a result, gear-shift failure.
Particulate filter (DPF/FAP): the most serious faults by engine and car
- High severityFrequency: Very frequentOM651EGR and particulate filter clogging, and emissions software updatesThe particulate filter and EGR clog up with short journeys, as on any diesel with these systems. In addition, Germany's KBA required software updates on several models with this engine between 2018 and 2021 because of a function that reduced EGR outside a temperature range.Repair (garage): €800–€2,500
- High severityFrequency: Common1.3 MultijetIncomplete particulate filter regenerations and oil dilutionIn heavy urban use, with short journeys that do not let the particulate filter regeneration finish, unburnt diesel passes into the sump and dilutes the oil; the level can rise on the dipstick and the oil loses its ability to lubricate. Repeated many times, it speeds up engine wear.
- High severityFrequency: Common2.0 HDiDPF clogging on additive-type systems (Eolys/cerine)The additive-type diesel particulate filter (DPF) of the 2.0 HDi clogs relatively easily on short journeys, especially on the 107/110 and 136-140 hp versions. The anti-pollution warning light comes on and, if ignored, the car loses power and may end up needing a new DPF.
- High severityFrequency: Common1.6 and 2.0 MultiJet IISaturated diesel particulate filter (DPF) from incomplete regenerationsIn urban use with short journeys, the particulate filter does not manage to complete its regeneration and becomes saturated; garages recommend a weekly motorway run to avoid it. The filter itself is among the weak points flagged in the 1.6 and 2.0 MultiJet II after a certain mileage.
Frequently asked questions
What is the exhaust gas temperature sensor for?
It measures the exhaust temperature and sends it to the ECU as a voltage. According to HELLA, the ECU uses it to control the mixture or particulate filter regeneration, and according to Bosch, it protects the turbo and the catalytic converters from overheating and allows the particulate filter to be regenerated effectively. The one for bank 1, sensor 1, sits between the manifold and the catalytic converter.[1][4][5]
Can I drive with code P0546?
The sources do not give a firm answer. CarParts does not call it critical, but says that the reduced power indicates a problem that deserves prompt attention; HELLA points out that a failed EGT sensor can increase emissions and consumption and cause problems with particulate filter regenerations. It is worth checking soon, especially on a diesel with a particulate filter.[1][4][5]
What is the difference between P0545 and P0546?
They are the same sensor (bank 1, sensor 1) with the signal in opposite directions: P0545 indicates a low signal and P0546 a high one. In the manual of a Toyota diesel, P0545 is set below 0.2 V and P0546 above 4.95 V for 3 seconds or more; other manufacturers use different thresholds.[2][6][8][9]
What is the difference between P0546 and P2033?
Both indicate a high signal from the bank 1 exhaust temperature sensor, but on different sensors: P0546 is sensor 1 and P2033 is sensor 2. In the Toyota manual, sensor 1 sits before the CCo catalytic converter and sensor 2 before the particulate filter; CarParts places bank 1 sensor 1 between the manifold and the catalytic converter.[1][6]
Do I have to replace the sensor if P0546 appears?
Not necessarily. The code points to the sensor circuit, which includes its wiring and its connector; CarParts also lists the ECU among the causes. First the connectors and wires are checked, the temperature reported by the sensor is looked at and the circuit is measured, and only then is the sensor replaced.[1][3][4][6]
Does P0546 mean the same on all brands?
Yes as far as the definition goes: codes starting with P0 are generic OBD-II codes. Each manufacturer decides the voltage threshold at which it is set.[6][7]
Will I pass the MOT with code P0546?
If the code has switched on the engine warning light, no: with that light on, the inspection records a serious defect, and on Euro 5 and Euro 6 cars the ITV (Spain's roadworthiness inspection, similar to the MOT) also reads the OBD diagnostic system. Repair the fault before you go; clearing the code just before the inspection does not help either, because it counts as a serious defect.[11]
Not sure what is wrong with your car? Describe what you notice in the symptom diagnosis or see all fault codes.
Sources
Every fact on this page links to its source. If you find an error, let us know.
- P0546 Code: Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 1CarParts.com · Technical documentation · consulted 4 October 2026
- P0546 - Exhaust Gas Temperature Sensor Circuit High | TaTThe Automotive Technician (TaT) · Technical documentation · consulted 4 October 2026
- P0546 OBD Error Code: Problem & SolutionsPartsAvatar · Technical documentation · consulted 4 October 2026
- Checking the exhaust gas temperature sensorHELLA (HELLA Tech World) · Manufacturer · consulted 4 October 2026
- Why are Exhaust Gas Temperature sensors required in modern diesel systems - EGTBosch Auto Parts · Manufacturer · consulted 4 October 2026
- ECD System, Diagnostic DTC: P0545, P0546, P2032, P2033, P242C, P242D (copia de un manual de taller de Toyota)corolla-club.ru · Technical documentation · consulted 4 October 2026
- On-board diagnosticsWikipedia · Other source · consulted 4 October 2026
- P0545 — Exhaust gas temperature sensor signal low - Bank 1, Sensor 1The Automotive Technician (TaT) · Technical documentation · consulted 4 October 2026
- Error Code P0545: What It Means & What To Do?PartsAvatar · Technical documentation · consulted 4 October 2026
- DTC P0546 EXHAUST TEMPERATURE SENSOR CIRCUIT HIGH-BANK 1 (9-2X 9346, 2005, 2.0T) (copia del manual de taller de Saab)Saab WIS Online (Saab Workshop Information System) · Technical documentation · consulted 4 October 2026
- Desmontando mitos: ¿puede pasar mi coche la ITV con el testigo de «avería motor» encendido?Diariomotor · Motoring press · published 8 March 2021 · consulted 2 October 2026 · in Spanish