P0546 – Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 1) – iCarsoft Official Store

Updated: October 2025 | Applies to: Audi, VW, BMW, Mercedes-Benz, GM, Toyota, Ford

🔍 What Does Code P0546 Mean?

The P0546 trouble code indicates a problem with the Exhaust Gas Temperature (EGT) Sensor Circuit High on Bank 1 Sensor 1. This means the Engine Control Module (ECM) has detected voltage readings that are too high from the EGT sensor.

The EGT sensor monitors exhaust gas temperature to protect the catalytic converter and diesel particulate filter (DPF). If it malfunctions, the ECM may trigger limp mode or disable DPF regeneration. Many drivers report seeing “P0546 code after DPF cleaning” or “EGT sensor voltage high on cold start.”

⚠️ Common Symptoms of P0546

Check Engine Light (CEL) illuminated
Reduced engine power or limp mode
Higher than normal exhaust temperature readings
DPF regeneration failure (for diesel vehicles)
Increased fuel consumption
Other codes such as P2033 or P247A stored simultaneously

On Audi A4 2.0T and VW TDI models, P0546 often appears after long idling or short urban driving cycles. In some Mercedes diesel cases, the EGT sensor wire near the turbo can melt or corrode due to heat exposure.

🔧 Common Causes of P0546

Failed EGT sensor (open or shorted circuit)
Damaged or corroded sensor connector
Broken wiring near the exhaust manifold
ECM detecting over-voltage due to internal short
Exhaust leak before the catalytic converter
Incorrect aftermarket sensor installation

A faulty sensor is the most common cause — but before replacement, always check wiring and voltage reference first. Using the wrong sensor resistance range (for instance, mixing P0544 and P0546 types) can also trigger this fault.

🧰 How to Diagnose P0546 Using iCarsoft CR MAX

Plug the iCarsoft CR MAX scanner into your OBD-II port and power on the ignition (engine off).
Select your vehicle and perform an Intelligent Diagnosis scan.
Confirm the stored code: P0546 – Exhaust Gas Temperature Sensor Circuit High.
Go to Live Data and view EGT Sensor Bank 1 Sensor 1 voltage.
Normal readings should range from 0.5V to 4.5V depending on exhaust temp.
If the reading is fixed (e.g. 5V constant), unplug the sensor — if voltage drops, the sensor is shorted internally.
Inspect wiring near the turbocharger and replace damaged sections.
Clear codes using CR MAX and verify the fix with a short test drive.

The iCarsoft CR MAX allows you to graph EGT sensor output in real time — extremely helpful for comparing Bank 1 vs Bank 2 readings.

🧩 Real Case Example

A 2016 VW Passat TDI showed code P0546 after a DPF regeneration attempt failed. The EGT Sensor 1 showed 4.98V in live data using the iCarsoft CR MAX, while other sensors were normal. Replacing the front EGT sensor (OEM Bosch 0281004576) fixed the issue instantly, and the DPF regeneration function resumed properly.

Another case involved a Mercedes-Benz E220 CDI where the harness insulation near the turbo melted, causing the same high-voltage reading. Repairing the wire resolved the problem without replacing the sensor.

🛠️ Repair and Maintenance Tips

Always use OEM EGT sensors (Bosch, Denso, NTK). Aftermarket sensors often misreport voltage.
Apply anti-seize on sensor threads before installation.
Check for exhaust leaks — they can alter sensor readings.
Perform a DPF regeneration cycle after replacement to confirm system health.
Use the Special Functions menu on iCarsoft CR MAX to reset EGT adaptation values.

💬 FAQ: Understanding and Fixing P0546

Q1: What causes the EGT sensor circuit high code P0546?

Typically, a failed sensor or shorted wiring near the turbocharger causes voltage spikes that trigger this code.

Q2: Can I drive with code P0546?

Short distances only. The vehicle may run rich and increase exhaust temperatures, risking catalytic converter damage if ignored.

Q3: How to test the EGT sensor with a multimeter?

Disconnect the sensor and measure resistance between signal and ground. Normal readings are 150–250Ω at room temperature. Infinite or zero indicates a fault.