P0046 on GMC
Turbocharger/Supercharger Boost Control 'A' Circuit Range/Performance
P0046 on GMC vehicles indicates turbocharger/supercharger boost control 'a' circuit range/performance. Au7o has documented this code across 1 GMC model — most commonly on Sierra 3500HD. P0046 is a generic powertrain code indicating a range/performance problem in the turbocharger or supercharger boost-control 'A' circuit — the computer's commanded boost-control signal does not match the actual measured response. This means the boost-control solenoid or actuator is responding too slowly, sticking, or producing implausible feedback rather than a clean electrical short or open. The driver may notice reduced power, surging boost, or a limp mode along with a check engine light. It should be diagnosed to restore proper boost regulation and protect the engine. Typical repair costs on GMC range from $200 to $3,500, depending on the specific model and root cause.
Common Causes of P0046
- •Sticking or worn boost-control solenoid/actuator
- •Carbon-fouled or binding variable-geometry turbo vanes
- •Vacuum leak or restricted vacuum line to the actuator
- •Wiring/connector resistance affecting the control signal
- •Boost pressure sensor inaccuracy
- •Worn turbocharger affecting boost response
P0046 on GMC by Model
GMC Sierra 3500HD(1 issue)
- Turbocharger VGT Vane Sticking and Boost Control Failure (Duramax LML/L5P)2011-2022
The variable geometry turbocharger (Garrett GT3788VA on LML, and similar VGT on L5P) used on 6.6L Duramax engines develops carbon buildup on the variable vanes, causing them to stick and resulting in loss of boost control. Owners report surging, lack of power under load, black smoke, and check engine lights. This is a widely documented issue in Duramax owner communities and referenced in multiple TSBs including 16-NA-026.
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View P0046 across all makes →Frequently Asked Questions
What does P0046 mean on GMC?▼
P0046 stands for "Turbocharger/Supercharger Boost Control 'A' Circuit Range/Performance." P0046 is a generic powertrain code indicating a range/performance problem in the turbocharger or supercharger boost-control 'A' circuit — the computer's commanded boost-control signal does not match the actual measured response. This means the boost-control solenoid or actuator is responding too slowly, sticking, or producing implausible feedback rather than a clean electrical short or open. The driver may notice reduced power, surging boost, or a limp mode along with a check engine light. It should be diagnosed to restore proper boost regulation and protect the engine. On GMC specifically, this code is documented across 1 model.
What causes P0046 on GMC vehicles?▼
Common causes on GMC: Sticking or worn boost-control solenoid/actuator, Carbon-fouled or binding variable-geometry turbo vanes, Vacuum leak or restricted vacuum line to the actuator, Wiring/connector resistance affecting the control signal, Boost pressure sensor inaccuracy. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0046 on a GMC?▼
Repair costs on GMC range from $200 to $3,500, depending on the specific model and root cause.
Which GMC models have P0046 documented?▼
Au7o has documented P0046 on 1 GMC model: Sierra 3500HD.