What Does P0546 Mean?
The ECM has detected that the exhaust gas temperature sensor circuit on Bank 1, Sensor 1 is reading above the expected voltage or resistance threshold. This high-input condition typically indicates an open circuit in the sensor wiring, a disconnected sensor, or a failed sensor with abnormally high resistance. The ECM defaults to a substitute value and may activate protective power-reduction strategies.
Common Causes
35%
Open circuit in the EGT sensor wiring harness caused by a broken wire, often from heat fatigue or vibration near the exhaust manifold
30%
Failed EGT sensor with open internal element due to thermal shock or age-related degradation
25%
Disconnected or loose EGT sensor connector with backed-out pins or broken locking tab
10%
EGT sensor signal wire shorted to battery voltage through a damaged harness contacting a power source
Diagnostic Steps
1
Step 1: Inspect the Bank 1 Sensor 1 EGT sensor connector for proper engagement, backed-out terminals, and corrosion. Verify the locking tab is intact and the connector is fully seated.
2
Step 2: Disconnect the sensor and measure resistance across the sensor element terminals. An open-loop (OL/infinity) reading confirms a failed sensor. Normal reading at room temperature is typically 100-200 ohms.
3
Step 3: With the sensor disconnected, use a jumper wire with a known resistor (100-150 ohm) across the ECM-side connector pins. If the ECM reads a valid temperature, the wiring is intact and the sensor is faulty.
4
Step 4: If the reading remains high with the test resistor, measure continuity of each wire from the sensor connector back to the ECM. Check for open circuits, particularly at flex points, harness clips near exhaust components, and firewall pass-throughs.
5
Step 5: Also check for voltage on the signal wire with key on; if battery voltage is present, trace the harness for a short to a power source. Repair all wiring faults with high-temperature wire rated for exhaust proximity.
Estimated Repair Cost
$70 - $300
Parts + labor, varies by vehicle and location
The ECM has detected that the exhaust gas temperature sensor circuit on Bank 1, Sensor 1 is reading above the expected voltage or resistance threshold. This high-input condition typically indicates an open circuit in the sensor wiring, a disconnected sensor, or a failed sensor with abnormally high r...
The most common cause of P0546 (Exhaust Gas Temperature Sensor Circuit High (Bank 1 Sensor 1)) is: Open circuit in the EGT sensor wiring harness caused by a broken wire, often from heat fatigue or vibration near the exhaust manifold
Typical repair costs for P0546 range from $70 to $300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A false high EGT reading may trigger unnecessary power derating or limp mode, reducing drivability. The ECM may also apply excessive fuel enrichment to cool perceived hot exhaust, wasting fuel and increasing emissions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0546 to identify the root cause.
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Quick Info
Category
Powertrain
System
Exhaust / Emission Control System
Difficulty
Type
Generic (SAE)
Recommended Tools
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