P0546
Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 1.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 5
- AreaVehicle speed, idle control and auxiliary inputs
- 46
- FaultThe specific fault in that area
What it means
P0546 means the control unit has seen a signal voltage from the Bank 1 Sensor 1 exhaust gas temperature sensor that is higher than the expected range. This usually points to an open circuit, a short to voltage or a faulty sensor. The sensor is normally fitted upstream of the turbocharger or catalyst on bank 1, but its exact position depends on the engine.
Symptoms
- Engine warning light on
- Reduced power or limp mode on some engines
- Turbo or exhaust protection strategies activating
- Particulate filter regeneration not completing or running poorly on diesels
- Possible failed emissions test
- Often no noticeable change in driving
Possible causes
- Faulty exhaust gas temperature sensor reading out of rangelikely
- Damaged, chafed or heat-affected wiring causing an open circuit or short to voltagelikely
- Corroded, loose or contaminated connector at the sensor or control unitlikely
- Sensor signal wire shorted to the reference or supply voltage in the harnesspossible
- Poor or missing sensor ground connectionpossible
- Fault in the control unit sensor input circuitrare
- Outdated control unit software where the manufacturer has issued a correction for this faultrare
How to diagnose
- Read all stored and pending codes and note the freeze frame data, including engine load, speed and coolant temperature.
- Check live data for the Bank 1 Sensor 1 temperature and compare it with other exhaust temperature sensors and with ambient temperature on a cold engine.
- Visually inspect the sensor, its wiring and the connector for heat damage, chafing, corrosion, moisture and loose pins.
- With the sensor unplugged, check whether the reading changes to a fixed value, which helps separate a sensor fault from a wiring fault.
- Measure the sensor resistance or signal against the manufacturer's specification, as values vary by sensor type and model.
- Check the supply, signal and ground wires for continuity and for shorts to voltage or ground, following the wiring diagram.
- Check for any manufacturer service information or software updates relating to this code for the specific vehicle.
- Clear the code and road test to confirm whether it returns, and recheck live data.
How to fix
- Replace the exhaust gas temperature sensor if it is out of specification or reading incorrectly.
- Repair or replace damaged wiring, and secure it away from hot or moving parts.
- Clean or replace corroded or damaged connectors and terminals.
- Repair any short to voltage or poor ground connection in the circuit.
- Update the control unit software only if a manufacturer correction exists for this fault.
- Replace or repair the control unit only after all wiring and sensor faults are ruled out.
Can I keep driving?
Medium severity
The car can usually be driven for a short time, but book it in soon. Without a valid temperature signal, exhaust and turbo protection may be compromised, and filter regeneration or power may be affected.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.