P0546 on GMC
Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 1
P0546 on GMC vehicles indicates exhaust gas temperature sensor circuit high bank 1 sensor 1. Au7o has documented this code across 1 GMC model — most commonly on Sierra 3500HD. This code means the engine computer detected an abnormally high voltage (or out-of-range high signal) from the exhaust gas temperature (EGT) sensor on Bank 1, Sensor 1. The EGT sensor monitors exhaust heat to protect components like the turbocharger, catalytic converter, and diesel particulate filter from overheating. A faulty reading can disable protective strategies and may put the engine into reduced-power mode. Typical repair costs on GMC range from $800 to $2,500, depending on the specific model and root cause.
Common Causes of P0546
- •Faulty exhaust gas temperature sensor
- •Open or shorted EGT sensor wiring
- •Corroded or loose sensor connector
- •Damaged sensor from excessive exhaust heat
- •Exhaust leak near the sensor
- •PCM circuit fault
P0546 on GMC by Model
GMC Sierra 3500HD(1 issue)
- Exhaust Manifold Cracking and Warping (Duramax L5P/LML)2015-2024
The cast iron exhaust manifolds on the Duramax diesel engine are prone to cracking and warping due to extreme exhaust gas temperatures and thermal cycling. Cracks typically develop at the manifold-to-head mounting points, causing exhaust leaks that produce a ticking noise on cold starts. The up-pipe connections also warp, allowing soot to blow onto engine components. This issue affects both the LML (2015-2016) and L5P (2017-2024) engines.
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View P0546 across all makes →Frequently Asked Questions
What does P0546 mean on GMC?▼
P0546 stands for "Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 1." This code means the engine computer detected an abnormally high voltage (or out-of-range high signal) from the exhaust gas temperature (EGT) sensor on Bank 1, Sensor 1. The EGT sensor monitors exhaust heat to protect components like the turbocharger, catalytic converter, and diesel particulate filter from overheating. A faulty reading can disable protective strategies and may put the engine into reduced-power mode. On GMC specifically, this code is documented across 1 model.
What causes P0546 on GMC vehicles?▼
Common causes on GMC: Faulty exhaust gas temperature sensor, Open or shorted EGT sensor wiring, Corroded or loose sensor connector, Damaged sensor from excessive exhaust heat, Exhaust leak near the sensor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0546 on a GMC?▼
Repair costs on GMC range from $800 to $2,500, depending on the specific model and root cause.
Which GMC models have P0546 documented?▼
Au7o has documented P0546 on 1 GMC model: Sierra 3500HD.